Research ArticleUltra-Wideband Dielectric Resonator Antenna DesignBased on Multilayer Form
FanWang 1 Chuanfang Zhang 1 Houjun Sun1 and Yu Xiao2
1School of Information and Electronics Beijing Institute of Technology Beijing 100081 China2Department of Electronic Engineering Tsinghua University Beijing 100084 China
Correspondence should be addressed to Chuanfang Zhang zcfbiteducn
Received 15 January 2019 Revised 28 March 2019 Accepted 3 April 2019 Published 16 April 2019
Academic Editor Paolo Burghignoli
Copyright copy 2019 FanWang et alThis is an open access article distributed under theCreative CommonsAttribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
In this paper an ultra-wideband dielectric resonator antenna (DRA) is investigated It basically covers the bandwidth from 6GHz to16GHz and achieves a relative bandwidth of 909 It is found that a wide bandwidth can be reached with a small DRA by adoptingmultilayer form Thus the dimension of the designed DRA element which is composed of nine-element phased-scanning lineararray is as small as 69mm x 82mm x 11mmWhile the maximum stable zenith gain is 62dB the lobe width is 3 dBThe operatingfrequency range of the antenna array is from 542GHz to 165GHz achieving a 1011 relative bandwidth A large scanning angle ofplusmn60∘ is realized within the operating frequency band with good scanning pattern and cross polarization To verify the design andsimulation a 1 times 9 DRA array is fabricated and measurements are carried out
1 Introduction
Ultra-wideband technology as one of the key technologiesfor integrated radio frequency plays an important role inthe integrated radio frequency system It is an importantfoundation for the upgrading of avionics systems Over thepast decades the rapid development of microwave materialsand electromagnetic simulation technology has laid a goodfoundation for the research and development of the dielectricresonator antenna (DRA) The DRA is relatively simple tofabricate and easy to excite It has a lightweight as well asa compact structure The main radiation structure of theDRA is composed of the microwave material with very lowloss and the antenna is radiating through the surface ofthe entire resonator except the ground Since there is nometal material no conductor and surface wave loss existwhich induces a very high radiation efficiency The DRA hasa variety of structures and large degrees of design freedomwith three-dimensional structure The basic way to extendthe DRA bandwidth is to reduce the Q-factor of the antennaby lessening the permittivity of the dielectric material Thismethod is mainly suitable for a single mode of operation Inaddition the introduction of multimode resonance is also an
important approach to extend the bandwidth of the DRAA DRA working on a high operating bandwidth (exceeding65 fractional bandwidth) realized with a hollow dielectriccylinder equipped with a top-mount spherical cap-lens anda suitably shaped metal reflector is presented in [1] Thisantenna allows achieving a high-gain (exceeding 14 dBi)excellent linearcircular polarization purity and a high front-to-back ratio (better than 20 dB) while a cylindrical DRAwhich employs some layers of uniaxial anisotropic materialsto increase the directivity of the antenna in the boresightdirection is proposed in [2] A cylindrical structure DRAto expand the bandwidth is introduced in [3] Coaxial feedand aperture coupled feed are used for exciting the antennaThe impedance bandwidth is 268 for coaxial feed and237 for aperture coupled feed DRAs of four differentcone shape structures are designed in [4] It can be seenthat the bandwidth of the inverted cone structure is widerthan that of the noninverted cone structure Besides thesplit cone structure excites more modes than all the othercone structures and has a much wider bandwidth that almostreached 50 A dielectric material (120576119903 = 20) is used as theradiation body to design a DRA with the conical structurein [5] This antenna is fed through the micro-strip line
HindawiInternational Journal of Antennas and PropagationVolume 2019 Article ID 4391474 10 pageshttpsdoiorg10115520194391474
2 International Journal of Antennas and Propagation
h1
h2
h3
Dielectric AL
W
Dielectric B
Dielectric C
Coaxial Probe
Feeding PatchDielectric Substrate
Ground Plane
z
xy
0
Figure 1 Configuration of the DRA element
615Aε = Bε = 102 233Cε =Dielectric A Dielectric B Dielectric C
Figure 2 Prototype of three dielectric materials
which simultaneously excites the fundamental mode and thehigher order mode and finally achieves a bandwidth of 272-1136GHzMultilayer dielectric structure is used in [6ndash9] It isalso an effective way to extend the bandwidth of DRA An X-band wideband stair-shaped structure DRA is introduced in[10] By using the two-step stair-shaped structure the DRAobtains an impedance bandwidth (11987811 lt minus10119889119861) of 543Another effective way to extend the bandwidth is making useof hybrid radiating structure as shown in [11]
The phased array DRA with characteristics of minia-turization and ultra-wideband is designed and discussed inthe paper The DRA element is composed of nine-elementphased-scanning linear array and is expanded in a multilayerform The return loss is reduced by adding a metal patchThis DRA can be used for the terminal equipment of satellitecommunication system (87GHz X-band and 1411GHz Ku-band) as well as the weather radar system
2 DRA Element Design
Ultra-wideband is one of the important trends in the devel-opment of DRA For a single dielectric material DRA high-permittivity is required to reduce the size of the antennaHowever using high-permittivity dielectricmaterial is equiv-alent to improving the Q-factor of the dielectric resonatorwhich reduces the antenna operating bandwidth That is
miniaturization and ultra-wideband for a single dielectricmaterial DRA are contradictoryThus an additional approachneeds to be considered to overcome the problem To expandthe bandwidth of DRA using the multilayer forms such aslaminates composed of dielectrics with same cross-sectionaldimension and different permittivities or structures intro-ducing suitable air layers (120576119903 = 1) is an effective way Dueto different natural resonant frequencies of the dielectricmaterials multimode resonances will be generated and thebandwidth will be expanded
Compared with other geometric forms of DRA therectangular formDRA has the advantages of being fabricatedsimply and possessing high design freedom Thus the pro-posed antenna element is designed in this form According to[12] the resonant frequency of the fundamental mode of therectangular formed DRA can be approximately computed as
1198910= 15 [1198861 + 1198862 (1199082ℎ) + 016 (1199082ℎ)
2]119908120587radic120576119903 (1)
1198861= 257 minus 08 ( 1198892ℎ) + 042 (
1198892ℎ)2
minus 005 ( 1198892ℎ)3
(2)
1198862= 271 ( 1198892ℎ)
minus0282
(3)
International Journal of Antennas and Propagation 3
without patch with patch
6 8 10 12 14 16 184Frequency (GHz)
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 3 Return loss comparison (with and without metal patch) of the DRA element
Return Loss
6 8 10 12 14 16 184Frequency (GHz)
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 4 Return loss of the DRA element
Realized Gain
minus4
minus2
0
2
4
6
Real
ized
Gai
n (d
B)
6 8 10 12 14 16 184Frequency (GHz)
Figure 5 Realized gain of the DRA element
4 International Journal of Antennas and Propagation
minus15
H-Plane E-Plane
minus10
minus5
0
50
30
60
90
120
150180
210
240
270
300
330
minus10
minus5
0
5
(a)
H-Plane E-Plane
minus20
minus15
minus10
minus5
0
5
100
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
5
10
(b)
H-Plane E-Plane
minus35minus30minus25minus20minus15minus10
minus505
030
60
90
120
150180
210
240
270
300
330
minus35minus30minus25minus20minus15minus10
minus505
(c)
Figure 6 E-plane and H-plane radiation patterns of the DRA element (a) at 7GHz (b) at 12GHz and (c) at 15GHz
L1
W
D
(a) (b)
Figure 7 Configuration of the DRA array (a) Array elements arrangement diagram (b) Prototype of the proposed DRA array
International Journal of Antennas and Propagation 5
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
6 8 10 12 14 16 184Frequency (dB)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
Act
ive R
etur
n Lo
ss (d
B)
Figure 8 Active return loss of the DRA array
H-PlaneE-Plane
minus120 minus60 0 60 120 180minus180θ (deg)
minus50
minus40
minus30
minus20
minus10
0
10
20
Gai
n (d
B)
Figure 9 E-plane and H-plane radiation patterns of the DRA array at 12GHz
where d w h are the length width and height of therectangular resonator respectively
Considering the availability and resonance characteristicsof the dielectric three different dielectrics are chosen forDRAdesignThe initial dimensions of the antenna are designed by(1) (2) and (3) and the antenna dimensions and dielectricarrangement are optimized by simulation software Figure 1depicts the configuration of the optimized DRA element Asshown in Figure 1 the antenna consists of three dielectricsdielectric A dielectric B and dielectric CThey have the samecross-sectional dimensions and different permittivities Thedimensions are 119871 = 82119898119898 119882 = 69119898119898 ℎ1 = 43119898119898ℎ2 = 4119898119898 and ℎ3 = 25119898119898 respectively The permittivities
are 120576119860 = 615 120576119861 = 102 and 120576119862 = 233 respectively as shownin Figure 2 The thickness of dielectric substrate is 0813mmand the permittivity is 120576119878 = 355 The connector used toexcite the antenna is the SMP connector and the lengthand diameter of the electrical probe are 7mm and 04mmrespectively The diameter of the hole in the ground planewhich the probe passes through is 05mm The length andwidth of the ground plane are 15mm and 10mm respectivelyA copper piece (length andwidth are 39mm)with a thicknessof 003mm is added between the side of the antenna and thecoaxial probe as the feeding patch to improve the impedancematching between them and thereby optimizing the returnloss The commercial product used to glue the three layers
6 International Journal of Antennas and Propagation
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 10 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 7GHz
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=-60deg Scanning Angle=30deg Scanning Angle=60deg
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 11 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 12GHz
is All Purpose AA Extra-glue produced by ARON ALPHAThe effect of the metal patch on the return loss of the DRA isshown in Figure 3
The DRA element is analyzed and optimized by using theelectromagnetic simulation software HFSS Figure 4 showsthe simulated return loss of the DRA It is shown that thereturn loss is better than -8dB when the frequency rangesfrom 6GHz to 16GHz Figure 5 depicts the change ofsimulated realized gain of the DRA with frequency variationIt is clear that the zenith gain of the antenna keeps increasingto the peak of 621dB at 112 GHz and then gradually decreasesdue to the slight cracking of the antenna beam at highfrequencies
Figure 6 illustrates the E-plane (YOZ-plane) and H-plane (XOZ-plane) radiation patterns of the DRA element at7GHz 12GHz and 15GHz respectively From these graphsseveral conclusions can be drawn (a) the antenna has a gooddirectional radiation characteristic at 7GHz where the 3 dBlobe width is widely reaching plusmn91∘ and the zenith gain is0 dB (b) the antenna also shows a good directional radiationcharacteristic at 12GHz where the 3 dB lobe width reachesplusmn60∘ with the zenith gain being 586dB (c) the zenith gaindrops to 433dB at 15GHz and the antenna exhibits a slightbeam cracking due to the exciting of high-order mode (d)the front-to-back ratio of the DRA element is better than96dB
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
2 International Journal of Antennas and Propagation
h1
h2
h3
Dielectric AL
W
Dielectric B
Dielectric C
Coaxial Probe
Feeding PatchDielectric Substrate
Ground Plane
z
xy
0
Figure 1 Configuration of the DRA element
615Aε = Bε = 102 233Cε =Dielectric A Dielectric B Dielectric C
Figure 2 Prototype of three dielectric materials
which simultaneously excites the fundamental mode and thehigher order mode and finally achieves a bandwidth of 272-1136GHzMultilayer dielectric structure is used in [6ndash9] It isalso an effective way to extend the bandwidth of DRA An X-band wideband stair-shaped structure DRA is introduced in[10] By using the two-step stair-shaped structure the DRAobtains an impedance bandwidth (11987811 lt minus10119889119861) of 543Another effective way to extend the bandwidth is making useof hybrid radiating structure as shown in [11]
The phased array DRA with characteristics of minia-turization and ultra-wideband is designed and discussed inthe paper The DRA element is composed of nine-elementphased-scanning linear array and is expanded in a multilayerform The return loss is reduced by adding a metal patchThis DRA can be used for the terminal equipment of satellitecommunication system (87GHz X-band and 1411GHz Ku-band) as well as the weather radar system
2 DRA Element Design
Ultra-wideband is one of the important trends in the devel-opment of DRA For a single dielectric material DRA high-permittivity is required to reduce the size of the antennaHowever using high-permittivity dielectricmaterial is equiv-alent to improving the Q-factor of the dielectric resonatorwhich reduces the antenna operating bandwidth That is
miniaturization and ultra-wideband for a single dielectricmaterial DRA are contradictoryThus an additional approachneeds to be considered to overcome the problem To expandthe bandwidth of DRA using the multilayer forms such aslaminates composed of dielectrics with same cross-sectionaldimension and different permittivities or structures intro-ducing suitable air layers (120576119903 = 1) is an effective way Dueto different natural resonant frequencies of the dielectricmaterials multimode resonances will be generated and thebandwidth will be expanded
Compared with other geometric forms of DRA therectangular formDRA has the advantages of being fabricatedsimply and possessing high design freedom Thus the pro-posed antenna element is designed in this form According to[12] the resonant frequency of the fundamental mode of therectangular formed DRA can be approximately computed as
1198910= 15 [1198861 + 1198862 (1199082ℎ) + 016 (1199082ℎ)
2]119908120587radic120576119903 (1)
1198861= 257 minus 08 ( 1198892ℎ) + 042 (
1198892ℎ)2
minus 005 ( 1198892ℎ)3
(2)
1198862= 271 ( 1198892ℎ)
minus0282
(3)
International Journal of Antennas and Propagation 3
without patch with patch
6 8 10 12 14 16 184Frequency (GHz)
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 3 Return loss comparison (with and without metal patch) of the DRA element
Return Loss
6 8 10 12 14 16 184Frequency (GHz)
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 4 Return loss of the DRA element
Realized Gain
minus4
minus2
0
2
4
6
Real
ized
Gai
n (d
B)
6 8 10 12 14 16 184Frequency (GHz)
Figure 5 Realized gain of the DRA element
4 International Journal of Antennas and Propagation
minus15
H-Plane E-Plane
minus10
minus5
0
50
30
60
90
120
150180
210
240
270
300
330
minus10
minus5
0
5
(a)
H-Plane E-Plane
minus20
minus15
minus10
minus5
0
5
100
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
5
10
(b)
H-Plane E-Plane
minus35minus30minus25minus20minus15minus10
minus505
030
60
90
120
150180
210
240
270
300
330
minus35minus30minus25minus20minus15minus10
minus505
(c)
Figure 6 E-plane and H-plane radiation patterns of the DRA element (a) at 7GHz (b) at 12GHz and (c) at 15GHz
L1
W
D
(a) (b)
Figure 7 Configuration of the DRA array (a) Array elements arrangement diagram (b) Prototype of the proposed DRA array
International Journal of Antennas and Propagation 5
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
6 8 10 12 14 16 184Frequency (dB)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
Act
ive R
etur
n Lo
ss (d
B)
Figure 8 Active return loss of the DRA array
H-PlaneE-Plane
minus120 minus60 0 60 120 180minus180θ (deg)
minus50
minus40
minus30
minus20
minus10
0
10
20
Gai
n (d
B)
Figure 9 E-plane and H-plane radiation patterns of the DRA array at 12GHz
where d w h are the length width and height of therectangular resonator respectively
Considering the availability and resonance characteristicsof the dielectric three different dielectrics are chosen forDRAdesignThe initial dimensions of the antenna are designed by(1) (2) and (3) and the antenna dimensions and dielectricarrangement are optimized by simulation software Figure 1depicts the configuration of the optimized DRA element Asshown in Figure 1 the antenna consists of three dielectricsdielectric A dielectric B and dielectric CThey have the samecross-sectional dimensions and different permittivities Thedimensions are 119871 = 82119898119898 119882 = 69119898119898 ℎ1 = 43119898119898ℎ2 = 4119898119898 and ℎ3 = 25119898119898 respectively The permittivities
are 120576119860 = 615 120576119861 = 102 and 120576119862 = 233 respectively as shownin Figure 2 The thickness of dielectric substrate is 0813mmand the permittivity is 120576119878 = 355 The connector used toexcite the antenna is the SMP connector and the lengthand diameter of the electrical probe are 7mm and 04mmrespectively The diameter of the hole in the ground planewhich the probe passes through is 05mm The length andwidth of the ground plane are 15mm and 10mm respectivelyA copper piece (length andwidth are 39mm)with a thicknessof 003mm is added between the side of the antenna and thecoaxial probe as the feeding patch to improve the impedancematching between them and thereby optimizing the returnloss The commercial product used to glue the three layers
6 International Journal of Antennas and Propagation
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 10 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 7GHz
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=-60deg Scanning Angle=30deg Scanning Angle=60deg
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 11 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 12GHz
is All Purpose AA Extra-glue produced by ARON ALPHAThe effect of the metal patch on the return loss of the DRA isshown in Figure 3
The DRA element is analyzed and optimized by using theelectromagnetic simulation software HFSS Figure 4 showsthe simulated return loss of the DRA It is shown that thereturn loss is better than -8dB when the frequency rangesfrom 6GHz to 16GHz Figure 5 depicts the change ofsimulated realized gain of the DRA with frequency variationIt is clear that the zenith gain of the antenna keeps increasingto the peak of 621dB at 112 GHz and then gradually decreasesdue to the slight cracking of the antenna beam at highfrequencies
Figure 6 illustrates the E-plane (YOZ-plane) and H-plane (XOZ-plane) radiation patterns of the DRA element at7GHz 12GHz and 15GHz respectively From these graphsseveral conclusions can be drawn (a) the antenna has a gooddirectional radiation characteristic at 7GHz where the 3 dBlobe width is widely reaching plusmn91∘ and the zenith gain is0 dB (b) the antenna also shows a good directional radiationcharacteristic at 12GHz where the 3 dB lobe width reachesplusmn60∘ with the zenith gain being 586dB (c) the zenith gaindrops to 433dB at 15GHz and the antenna exhibits a slightbeam cracking due to the exciting of high-order mode (d)the front-to-back ratio of the DRA element is better than96dB
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
International Journal of Antennas and Propagation 3
without patch with patch
6 8 10 12 14 16 184Frequency (GHz)
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 3 Return loss comparison (with and without metal patch) of the DRA element
Return Loss
6 8 10 12 14 16 184Frequency (GHz)
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 4 Return loss of the DRA element
Realized Gain
minus4
minus2
0
2
4
6
Real
ized
Gai
n (d
B)
6 8 10 12 14 16 184Frequency (GHz)
Figure 5 Realized gain of the DRA element
4 International Journal of Antennas and Propagation
minus15
H-Plane E-Plane
minus10
minus5
0
50
30
60
90
120
150180
210
240
270
300
330
minus10
minus5
0
5
(a)
H-Plane E-Plane
minus20
minus15
minus10
minus5
0
5
100
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
5
10
(b)
H-Plane E-Plane
minus35minus30minus25minus20minus15minus10
minus505
030
60
90
120
150180
210
240
270
300
330
minus35minus30minus25minus20minus15minus10
minus505
(c)
Figure 6 E-plane and H-plane radiation patterns of the DRA element (a) at 7GHz (b) at 12GHz and (c) at 15GHz
L1
W
D
(a) (b)
Figure 7 Configuration of the DRA array (a) Array elements arrangement diagram (b) Prototype of the proposed DRA array
International Journal of Antennas and Propagation 5
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
6 8 10 12 14 16 184Frequency (dB)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
Act
ive R
etur
n Lo
ss (d
B)
Figure 8 Active return loss of the DRA array
H-PlaneE-Plane
minus120 minus60 0 60 120 180minus180θ (deg)
minus50
minus40
minus30
minus20
minus10
0
10
20
Gai
n (d
B)
Figure 9 E-plane and H-plane radiation patterns of the DRA array at 12GHz
where d w h are the length width and height of therectangular resonator respectively
Considering the availability and resonance characteristicsof the dielectric three different dielectrics are chosen forDRAdesignThe initial dimensions of the antenna are designed by(1) (2) and (3) and the antenna dimensions and dielectricarrangement are optimized by simulation software Figure 1depicts the configuration of the optimized DRA element Asshown in Figure 1 the antenna consists of three dielectricsdielectric A dielectric B and dielectric CThey have the samecross-sectional dimensions and different permittivities Thedimensions are 119871 = 82119898119898 119882 = 69119898119898 ℎ1 = 43119898119898ℎ2 = 4119898119898 and ℎ3 = 25119898119898 respectively The permittivities
are 120576119860 = 615 120576119861 = 102 and 120576119862 = 233 respectively as shownin Figure 2 The thickness of dielectric substrate is 0813mmand the permittivity is 120576119878 = 355 The connector used toexcite the antenna is the SMP connector and the lengthand diameter of the electrical probe are 7mm and 04mmrespectively The diameter of the hole in the ground planewhich the probe passes through is 05mm The length andwidth of the ground plane are 15mm and 10mm respectivelyA copper piece (length andwidth are 39mm)with a thicknessof 003mm is added between the side of the antenna and thecoaxial probe as the feeding patch to improve the impedancematching between them and thereby optimizing the returnloss The commercial product used to glue the three layers
6 International Journal of Antennas and Propagation
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 10 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 7GHz
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=-60deg Scanning Angle=30deg Scanning Angle=60deg
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 11 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 12GHz
is All Purpose AA Extra-glue produced by ARON ALPHAThe effect of the metal patch on the return loss of the DRA isshown in Figure 3
The DRA element is analyzed and optimized by using theelectromagnetic simulation software HFSS Figure 4 showsthe simulated return loss of the DRA It is shown that thereturn loss is better than -8dB when the frequency rangesfrom 6GHz to 16GHz Figure 5 depicts the change ofsimulated realized gain of the DRA with frequency variationIt is clear that the zenith gain of the antenna keeps increasingto the peak of 621dB at 112 GHz and then gradually decreasesdue to the slight cracking of the antenna beam at highfrequencies
Figure 6 illustrates the E-plane (YOZ-plane) and H-plane (XOZ-plane) radiation patterns of the DRA element at7GHz 12GHz and 15GHz respectively From these graphsseveral conclusions can be drawn (a) the antenna has a gooddirectional radiation characteristic at 7GHz where the 3 dBlobe width is widely reaching plusmn91∘ and the zenith gain is0 dB (b) the antenna also shows a good directional radiationcharacteristic at 12GHz where the 3 dB lobe width reachesplusmn60∘ with the zenith gain being 586dB (c) the zenith gaindrops to 433dB at 15GHz and the antenna exhibits a slightbeam cracking due to the exciting of high-order mode (d)the front-to-back ratio of the DRA element is better than96dB
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
4 International Journal of Antennas and Propagation
minus15
H-Plane E-Plane
minus10
minus5
0
50
30
60
90
120
150180
210
240
270
300
330
minus10
minus5
0
5
(a)
H-Plane E-Plane
minus20
minus15
minus10
minus5
0
5
100
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
5
10
(b)
H-Plane E-Plane
minus35minus30minus25minus20minus15minus10
minus505
030
60
90
120
150180
210
240
270
300
330
minus35minus30minus25minus20minus15minus10
minus505
(c)
Figure 6 E-plane and H-plane radiation patterns of the DRA element (a) at 7GHz (b) at 12GHz and (c) at 15GHz
L1
W
D
(a) (b)
Figure 7 Configuration of the DRA array (a) Array elements arrangement diagram (b) Prototype of the proposed DRA array
International Journal of Antennas and Propagation 5
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
6 8 10 12 14 16 184Frequency (dB)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
Act
ive R
etur
n Lo
ss (d
B)
Figure 8 Active return loss of the DRA array
H-PlaneE-Plane
minus120 minus60 0 60 120 180minus180θ (deg)
minus50
minus40
minus30
minus20
minus10
0
10
20
Gai
n (d
B)
Figure 9 E-plane and H-plane radiation patterns of the DRA array at 12GHz
where d w h are the length width and height of therectangular resonator respectively
Considering the availability and resonance characteristicsof the dielectric three different dielectrics are chosen forDRAdesignThe initial dimensions of the antenna are designed by(1) (2) and (3) and the antenna dimensions and dielectricarrangement are optimized by simulation software Figure 1depicts the configuration of the optimized DRA element Asshown in Figure 1 the antenna consists of three dielectricsdielectric A dielectric B and dielectric CThey have the samecross-sectional dimensions and different permittivities Thedimensions are 119871 = 82119898119898 119882 = 69119898119898 ℎ1 = 43119898119898ℎ2 = 4119898119898 and ℎ3 = 25119898119898 respectively The permittivities
are 120576119860 = 615 120576119861 = 102 and 120576119862 = 233 respectively as shownin Figure 2 The thickness of dielectric substrate is 0813mmand the permittivity is 120576119878 = 355 The connector used toexcite the antenna is the SMP connector and the lengthand diameter of the electrical probe are 7mm and 04mmrespectively The diameter of the hole in the ground planewhich the probe passes through is 05mm The length andwidth of the ground plane are 15mm and 10mm respectivelyA copper piece (length andwidth are 39mm)with a thicknessof 003mm is added between the side of the antenna and thecoaxial probe as the feeding patch to improve the impedancematching between them and thereby optimizing the returnloss The commercial product used to glue the three layers
6 International Journal of Antennas and Propagation
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 10 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 7GHz
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=-60deg Scanning Angle=30deg Scanning Angle=60deg
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 11 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 12GHz
is All Purpose AA Extra-glue produced by ARON ALPHAThe effect of the metal patch on the return loss of the DRA isshown in Figure 3
The DRA element is analyzed and optimized by using theelectromagnetic simulation software HFSS Figure 4 showsthe simulated return loss of the DRA It is shown that thereturn loss is better than -8dB when the frequency rangesfrom 6GHz to 16GHz Figure 5 depicts the change ofsimulated realized gain of the DRA with frequency variationIt is clear that the zenith gain of the antenna keeps increasingto the peak of 621dB at 112 GHz and then gradually decreasesdue to the slight cracking of the antenna beam at highfrequencies
Figure 6 illustrates the E-plane (YOZ-plane) and H-plane (XOZ-plane) radiation patterns of the DRA element at7GHz 12GHz and 15GHz respectively From these graphsseveral conclusions can be drawn (a) the antenna has a gooddirectional radiation characteristic at 7GHz where the 3 dBlobe width is widely reaching plusmn91∘ and the zenith gain is0 dB (b) the antenna also shows a good directional radiationcharacteristic at 12GHz where the 3 dB lobe width reachesplusmn60∘ with the zenith gain being 586dB (c) the zenith gaindrops to 433dB at 15GHz and the antenna exhibits a slightbeam cracking due to the exciting of high-order mode (d)the front-to-back ratio of the DRA element is better than96dB
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
International Journal of Antennas and Propagation 5
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
6 8 10 12 14 16 184Frequency (dB)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
Act
ive R
etur
n Lo
ss (d
B)
Figure 8 Active return loss of the DRA array
H-PlaneE-Plane
minus120 minus60 0 60 120 180minus180θ (deg)
minus50
minus40
minus30
minus20
minus10
0
10
20
Gai
n (d
B)
Figure 9 E-plane and H-plane radiation patterns of the DRA array at 12GHz
where d w h are the length width and height of therectangular resonator respectively
Considering the availability and resonance characteristicsof the dielectric three different dielectrics are chosen forDRAdesignThe initial dimensions of the antenna are designed by(1) (2) and (3) and the antenna dimensions and dielectricarrangement are optimized by simulation software Figure 1depicts the configuration of the optimized DRA element Asshown in Figure 1 the antenna consists of three dielectricsdielectric A dielectric B and dielectric CThey have the samecross-sectional dimensions and different permittivities Thedimensions are 119871 = 82119898119898 119882 = 69119898119898 ℎ1 = 43119898119898ℎ2 = 4119898119898 and ℎ3 = 25119898119898 respectively The permittivities
are 120576119860 = 615 120576119861 = 102 and 120576119862 = 233 respectively as shownin Figure 2 The thickness of dielectric substrate is 0813mmand the permittivity is 120576119878 = 355 The connector used toexcite the antenna is the SMP connector and the lengthand diameter of the electrical probe are 7mm and 04mmrespectively The diameter of the hole in the ground planewhich the probe passes through is 05mm The length andwidth of the ground plane are 15mm and 10mm respectivelyA copper piece (length andwidth are 39mm)with a thicknessof 003mm is added between the side of the antenna and thecoaxial probe as the feeding patch to improve the impedancematching between them and thereby optimizing the returnloss The commercial product used to glue the three layers
6 International Journal of Antennas and Propagation
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 10 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 7GHz
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=-60deg Scanning Angle=30deg Scanning Angle=60deg
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 11 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 12GHz
is All Purpose AA Extra-glue produced by ARON ALPHAThe effect of the metal patch on the return loss of the DRA isshown in Figure 3
The DRA element is analyzed and optimized by using theelectromagnetic simulation software HFSS Figure 4 showsthe simulated return loss of the DRA It is shown that thereturn loss is better than -8dB when the frequency rangesfrom 6GHz to 16GHz Figure 5 depicts the change ofsimulated realized gain of the DRA with frequency variationIt is clear that the zenith gain of the antenna keeps increasingto the peak of 621dB at 112 GHz and then gradually decreasesdue to the slight cracking of the antenna beam at highfrequencies
Figure 6 illustrates the E-plane (YOZ-plane) and H-plane (XOZ-plane) radiation patterns of the DRA element at7GHz 12GHz and 15GHz respectively From these graphsseveral conclusions can be drawn (a) the antenna has a gooddirectional radiation characteristic at 7GHz where the 3 dBlobe width is widely reaching plusmn91∘ and the zenith gain is0 dB (b) the antenna also shows a good directional radiationcharacteristic at 12GHz where the 3 dB lobe width reachesplusmn60∘ with the zenith gain being 586dB (c) the zenith gaindrops to 433dB at 15GHz and the antenna exhibits a slightbeam cracking due to the exciting of high-order mode (d)the front-to-back ratio of the DRA element is better than96dB
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
6 International Journal of Antennas and Propagation
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 10 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 7GHz
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=-60deg Scanning Angle=30deg Scanning Angle=60deg
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 11 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 12GHz
is All Purpose AA Extra-glue produced by ARON ALPHAThe effect of the metal patch on the return loss of the DRA isshown in Figure 3
The DRA element is analyzed and optimized by using theelectromagnetic simulation software HFSS Figure 4 showsthe simulated return loss of the DRA It is shown that thereturn loss is better than -8dB when the frequency rangesfrom 6GHz to 16GHz Figure 5 depicts the change ofsimulated realized gain of the DRA with frequency variationIt is clear that the zenith gain of the antenna keeps increasingto the peak of 621dB at 112 GHz and then gradually decreasesdue to the slight cracking of the antenna beam at highfrequencies
Figure 6 illustrates the E-plane (YOZ-plane) and H-plane (XOZ-plane) radiation patterns of the DRA element at7GHz 12GHz and 15GHz respectively From these graphsseveral conclusions can be drawn (a) the antenna has a gooddirectional radiation characteristic at 7GHz where the 3 dBlobe width is widely reaching plusmn91∘ and the zenith gain is0 dB (b) the antenna also shows a good directional radiationcharacteristic at 12GHz where the 3 dB lobe width reachesplusmn60∘ with the zenith gain being 586dB (c) the zenith gaindrops to 433dB at 15GHz and the antenna exhibits a slightbeam cracking due to the exciting of high-order mode (d)the front-to-back ratio of the DRA element is better than96dB
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
International Journal of Antennas and Propagation 7
Scanning Angle=-60deg Scanning Angle=-30deg Scanning Angle=0deg Scanning Angle=30deg Scanning Angle=60deg
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180θ (deg)
Figure 12 H-plane radiation patterns at 120579 = 0∘ plusmn30∘ plusmn60∘ of the DRA array at 15GHz
Table 1 Main technical specification of the DRA array
Technical indicator RequirementOperating frequency band 6119866119867119911 119905119900 16119866119867119911Active standing wave ratio 120588 lt 3Scan angle 120579 gt 60∘6119866119867119911 119905119900 12119866119867119911
120579 gt 30∘12119866119867119911 119905119900 16119866119867119911
3 DRA Array Design
The proposed DRA element is extended to a linear array with1 times 9 elements The main technical requirements of the DRAarray are shown in Table 1
In order to avoid the grating lobes of the antenna arrayduring scanning the element spacing 119889 needs to follow
119889 le (1 minus 1119873) 1205821 + 1003816100381610038161003816sin 1205791198781003816100381610038161003816 (4)
where 120582 is the free-space wavelength corresponding to thehighest operation frequency of the antenna array 120579
119878is the
maximum scan angle of the antenna array 119873 is the numberof the elements
According to (4) and Table 1 it can be obtained that 119889 le125119898119898
Figure 7 shows the configuration of the DRA array NineDRA elements are placed on the dielectric substrate at equalintervals along the H-plane The dimensions of the array are1198711 = 100119898119898119882 = 15119898119898 and119863 = 10119898119898 respectively
Figure 8 depicts the active return loss of the DRA arrayat the scan angles of 120579 = 0∘ plusmn30∘ plusmn60∘ It can be seen thatall active return losses are better than -6dB The E-plane andH-plane radiation patterns at 12GHz without scanning areshown in Figure 9 The maximum gain of the DRA arrayexceeds 14 dB When the operating frequencies are 7GHz
12GHz and 15GHz the H-plane radiation patterns of theDRA array at different scan angles are given from Figures10ndash12 Taking the case when the scan angle is 60∘ the arraygains are 749dB 1177dB and 625dB when the operatingfrequencies are 7GHz 12GHz and 15GHz respectively
The primary polarization and cross polarization of theDRA array are shown in Figure 13The E-plane cross-polarization level of the DRA array is less than -296dB andthe H-plane cross-polarization level is less than -156dB in allcases
4 Experiments and Discussions
To verify the feasibility of the design a DRA array is fabri-cated and measured in microwave anechoic chamber Due tothe limitations of the test conditions the characteristics of theelement in the array are mainly measured The comparisonsbetween the measurement results and the simulation resultsare shown in Figures 14 and 15
Figure 14 shows the comparison of the return lossbetween measurement and simulation As seen clearly inthe graph actual measured result of the antenna return lossis basically better than 10 dB when the frequency rangesfrom 6GHz to 16GHz However there is a slight differencefrom the simulation result that the resonance point ofthe measured result is slightly increased The main reasonfor this result is that the air gap is introduced when theuneven application of the glue occurs during fabricatingthe dielectric block which causes multiple resonances ofthe antenna Figure 15 depicts the comparison of radiationpatterns between measurement and simulation The mea-sured radiation patterns of the antenna have some differencesfrom the simulation results mainly because of the fabricatingtolerances of the antenna and the permittivity deviations ofthe dielectric plate Moreover measurement errors and effect
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
8 International Journal of Antennas and Propagation
EXP ECP
minus60
minus50
minus40
minus30
minus20
minus10
0
10Re
aliz
ed G
ain
(dB)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(a)
HXP HCP
minus70
minus60
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(b)
EXP ECP
minus80
minus60
minus40
minus20
0
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(c)
HXP HCP
minus120 minus60 0 60 120 180minus180Frequency (GHz)
minus60
minus50
minus40
minus30
minus20
minus10
0
10
20Re
aliz
ed G
ain
(dB)
(d)
EXP ECP
minus50
minus40
minus30
minus20
minus10
0
10
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(e)
HXP HCP
minus40
minus30
minus20
minus10
0
10
20
Real
ized
Gai
n (d
B)
minus120 minus60 0 60 120 180minus180Frequency (GHz)
(f)
Figure 13 Primary polarization and cross polarization of the DRA array (a) E-plane at 7GHz (b) H-plane at 7GHz (c) E-plane at 12GHz(d) H-plane at 12GHz (e) E-plane at 15GHz (f) H-plane at 15GHz
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
International Journal of Antennas and Propagation 9
Simulation Measurement
9 12 15 186Frequency (GHz)
minus35
minus30
minus25
minus20
minus15
minus10
minus5
0
Retu
rn L
oss (
dB)
Figure 14 Comparison of return loss between measurement and simulation
minus25minus20minus15minus10
minus50
030
60
90
120
150180
210
240
270
300
330
minus30minus25minus20minus15minus10
minus50
SimulationMeasurement
(a)
minus20
minus15
minus10
minus5
00
30
60
90
120
150180
210
240
270
300
330
minus15
minus10
minus5
0
SimulationMeasurement
(b)
minus30minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus25minus20minus15minus10
minus505
10
SimulationMeasurement
(c)
minus25minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(d)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus15minus10
minus505
10
Simulation Measurement
(e)
minus20minus15minus10
minus505
100
30
60
90
120
150180
210
240
270
300
330
minus20minus15minus10
minus505
10
SimulationMeasurement
(f)
Figure 15 Comparison of radiation patterns between measurement and simulation (a) E-plane at 6GHz (b) H-plane at 6GHz (c) E-planeat 11 GHz (d) H-plane at 11 GHz (e) E-plane at 16GHz (f) H-plane at 16GHz
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
10 International Journal of Antennas and Propagation
of the SMP connector also lead the discrepancy between thesimulation and measurement results Such discrepancies arealso observed in [2 13 14]
5 Conclusions
When studying an ultra-wideband DRA covering the band-width from6GHz to 16GHz it is found that theDRAelementcan achieve a relative bandwidth of 909 by adoptingmultilayer form The designed DRA element composed ofa nine-element phased-scanning linear array can finallyachieve a 1011 relative bandwidth By both simulating withANSYS HFSS and carrying out experiments the correctnessof the simulation is verified and the actual performance isacceptable
Data Availability
The data used to support the findings of this study areincluded within the article
Conflicts of Interest
The authors declare that there are no conflicts of interestregarding the publication of this paper
References
[1] R Cicchetti A Faraone EMiozzi R Ravanelli andO Testa ldquoAhigh-gain mushroom-shaped dielectric resonator antenna forwidebandwireless applicationsrdquo IEEETransactions onAntennasand Propagation vol 64 no 7 pp 2848ndash2861 2016
[2] S FakhteHOraizi LMatekovits andGDassano ldquoCylindricalanisotropic dielectric resonator antenna with improved gainrdquoInstitute of Electrical and Electronics Engineers Transactions onAntennas and Propagation vol 65 no 3 pp 1404ndash1409 2017
[3] R Chair A A Kishk and K F Lee ldquoWideband simplecylindrical dielectric resonator antennasrdquo IEEE Microwave andWireless Components Letters vol 15 no 4 pp 241ndash243 2005
[4] A A Kishk Y Yin and A W Glisson ldquoConical dielectric res-onator antennas for wide-band applicationsrdquo IEEE Transactionson Antennas and Propagation vol 50 no 4 pp 469ndash474 2002
[5] G Varshney P Praveen R S Yaduvanshi and V S PandeyldquoConical shape dielectric resonator antenna for ultra wide bandapplicationsrdquo in Proceedings of the 2015 International Conferenceon Computing Communication and Automation ICCCA 2015pp 1304ndash1307 India May 2015
[6] Y Ge K P Esselle and T S Bird ldquoCompact dielectricresonator antennas with ultrawide 60ndash110 bandwidthrdquo IEEETransactions on Antennas and Propagation vol 59 no 9 pp3445ndash3448 2011
[7] G D Makwana and D Ghodgaonkar ldquoWideband stacked rect-angular dielectric resonator antenna at 52 GHzrdquo InternationalJournal of Electromagnetics and Applications vol 2 no 3 pp41ndash45 2012
[8] W Huang and A A Kishk ldquoCompact wideband multi-layercylindrical dielectric resonator antennasrdquo IET MicrowavesAntennas amp Propagation vol 1 no 5 pp 998ndash1005 2007
[9] Y M Pan and S Y Zheng ldquoA low-profile stacked dielectricresonator antenna with high-gain and wide bandwidthrdquo IEEE
Antennas and Wireless Propagation Letters vol 15 pp 68ndash712016
[10] R Chair A A Kishk and K F Lee ldquoWideband stair-shapeddielectric resonator antennas in IET Microwavesrdquo Antennas ampPropagation vol 1 no 2 pp 299ndash305 April 2007
[11] M Lapierre Y M M Antar A Ittipiboon and A PetosaldquoUltra wideband monopoledielectric resonator antennardquo IEEEMicrowave and Wireless Components Letters vol 15 no 1 pp7ndash9 2005
[12] A Petosa ielectric Resonator Antenna Handbook (Artech HouseAntennas and Propagation Library) Artech House NorwoodMA USA 2007
[13] P Gupta D Guha andC Kumar ldquoDielectric resonator workingas feed as well as antenna new concept for dual-mode dual-band improved designrdquo IEEE Transactions on Antennas andPropagation vol 64 no 4 pp 1497ndash1502 2016
[14] S Fakhte H Oraizi and L Matekovits ldquoHigh gain rectangulardielectric resonator antenna using uniaxial material at funda-mental moderdquo IEEE Transactions on Antennas and Propagationvol 65 no 1 pp 342ndash347 2017
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom
International Journal of
AerospaceEngineeringHindawiwwwhindawicom Volume 2018
RoboticsJournal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Active and Passive Electronic Components
VLSI Design
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Shock and Vibration
Hindawiwwwhindawicom Volume 2018
Civil EngineeringAdvances in
Acoustics and VibrationAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Electrical and Computer Engineering
Journal of
Advances inOptoElectronics
Hindawiwwwhindawicom
Volume 2018
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
Control Scienceand Engineering
Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom
Journal ofEngineeringVolume 2018
SensorsJournal of
Hindawiwwwhindawicom Volume 2018
International Journal of
RotatingMachinery
Hindawiwwwhindawicom Volume 2018
Modelling ampSimulationin EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Chemical EngineeringInternational Journal of Antennas and
Propagation
International Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Navigation and Observation
International Journal of
Hindawi
wwwhindawicom Volume 2018
Advances in
Multimedia
Submit your manuscripts atwwwhindawicom