HighGainArrayofMonopoles-CoupledAntennasfor ...International Journal of Antennas and Propagation 3...

Hindawi Publishing CorporationInternational Journal of Antennas and PropagationVolume 2012, Article ID 725745, 8 pagesdoi:10.1155/2012/725745

Research Article

High Gain Array of Monopoles-Coupled Antennas forWireless Applications

Ahmad El Sayed Ahmad,1 Marc Thevenot,2 Jean-Marie Floc’h,1 and Mohamad Mantash1

1 IETR, CNRS, UMR 6164, 20 Avenue des Buttes de Coesmes, 35043 Rennes, France2 XLIM, CNRS, UMR 6172, 123 Avenue Albert Thomas, 87060 Limoges, France

Correspondence should be addressed to Ahmad El Sayed Ahmad, [email protected]

Received 7 June 2012; Revised 27 September 2012; Accepted 11 October 2012

Academic Editor: Huanhuan Gu

Copyright © 2012 Ahmad El Sayed Ahmad et al. This is an open access article distributed under the Creative CommonsAttribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work isproperly cited.

An array of monopole antennas over a ground plane that radiates a directive lobe in the end-fire direction are described in thispaper. The design uses the rigorous method described by Drouet et al. 2008 in order to synthesize the radiation through thestrong cumulative coupling between the monopoles. A gain higher than 20 dB was achieved in the end-fire direction over a 4.5%bandwidth. However, the antenna has been tilted in order to compensate the beam deviation caused by the edge diffraction. Aprototype with 12 elements has been manufactured in order to validate the antenna principle and the whole antenna is successfullymeasured. The prototype was studied with the software CST-Microwave Studio and the feed network has been designed withAgilent ADS.

1. Introduction

This paper deals with the design of the vehicular antennathat must satisfy some particular requirements. Firstly, thisantenna has to be integrated on the roof that induces a low-profile antenna working over a ground plane. Secondly, anend-fire antenna which radiates toward the horizon mustbe used to communicate with the base stations. Finally, theantenna gain must be high in order to reduce the number ofbase stations. The design of an antenna that satisfies all thesespecifications is very difficult to perform.

Linear monopole arrays are extensively used in manyantenna systems due to their simplicity, low cost, polar-ization purity, reasonable bandwidth, and power-handlingcapability [1]. However, the strong mutual coupling betweenneighbored antenna elements also results in radiation pat-terns and matching degradations. The feed network can alsobe directly affected. It has been theoretically demonstratedthat mutual coupling effects on radiation patterns can bereduced with appropriate loads [2–5].

The aim of this paper is to design a linear arrayof monopoles by managing the coupling. Moreover, theantenna design must be robust and easy to manufacture in

order to be integrated on a vehicle roof, and, thus, to undergooutdoor conditions such as rain and wind.

In the first part, the global design method will bebriefly explained. Then, the principle, the design, and theperformances of a linear array of 12 monopoles will be given.In the second part, an array of 4 × 12 monopoles fed by afeed network will be described. The last section discusses thedesign of 4 × 12 monopoles that would be compared to aYagi antenna.

2. Basic Structure

2.1. Principle. The basic structure is composed of twelvemonopoles and a feed network. The strong interactionsbetween the monopoles need to design the feed network witha great accuracy in order to optimize the directivity.

The objective consists of the determination of theimpedance matching and the incident power to reach boththe objective radiation pattern and the best matching for themonopole array.

We employ the method described in [6] for the designof the array antenna with strong coupling: by using CST-Microwave studio we compute the [S] matrix and the 12

2 International Journal of Antennas and Propagation

radiation patterns when the 12 monopoles are successivelyfed. These radiation patterns are φ1 to φ12 (1). An objectiveradiation pattern φobj is proposed. This objective radiationpattern can be the linear combination of the radiationpattern of one monopole on its limited ground planemultiplied by an array factor (2). In this relation, d is thedistance between each monopole and ϕi is the phase of theith monopole.

Equation (1) provides the weights that must be applied tothe monopoles’ radiation pattern. Equation (3) leads to theantenna impedances to be considered as a reference (Zref) inorder to reach the matching and (4) gives the input wavesthat the feed network must achieve:

[φ1φ2 · · ·φi

]

⎛

⎜⎜⎜⎜⎝

β1β2...βi

⎞

⎟⎟⎟⎟⎠≈ φobj with 1 ≤ i ≤ 12 (1)

φobj =12∑

i=1exp

[−(k0 · d · sin(θ) + ϕi) · i] · φmonopole (2)

Zref i =(

50 · [I + S](β)[I − S](β)

)∗(3)

ai =√

50 · [I + S](β)√�(Zref i)Z∗ref i

, (4)

where φi is the ith monopole radiation pattern, φobj is theobjective radiation pattern, βi is the weight that must beapplied to the ith monopole radiation pattern, d is thedistance between each monopole, k0 = 2π/λ0 (λ0 free spacewavelengths), ϕi is the phase shift at ith monopole, and [S] isthe coupling matrix.

2.2. Design and Performances of the Array of 12 Monopoles. Asexplained in Section 1, the application is a communicationsystem that uses the WIMAX protocol between a vehicleand base stations. The objective is to establish a high-gain monopole array that radiates a directional beam inthe azimuthal plane within the frequency band 5.47 GHz–5.725 GHz. In this section, we propose the complete designof the array of monopoles with its feed network. Theoptimization frequency is 5.6 GHz.

In order to achieve a radiation with a single lobe inthe direction of the array alignment, the space between twonearby monopoles must stay lower than 0.5 λ0: we havechosen 0.45 λ0 (24.12 mm) for our design. Twelve monopolesare set on a ground plane whose dimensions are Lx = 100 mmand Ly = 330 mm (Figure 1). The monopole lengths arelisted into Table 1 (length) and their diameter is 2.53 mm.The connections between the monopoles and the feednetwork’s ports are achieved with 50Ω coaxial transitionswhich are drilled through the ground plane (Figure 2). Thefeed network is printed back to the antenna ground plane,onto a 0.508 mm thick Duroı̈d 6002 substrate (εr = 2.94,tgδ = 0.0012).

The array of monopoles is positioned on a limitedground plane. In the limited ground plane size case, the

X

Y

Z

Figure 1: The array antenna is composed of 12 monopoles.

Teflon εr: 2.08

radiusIn: 0.5 mmOut: 1.7 mm

7.5 mm1.2 mmGround plane

height: 5 mm

24.12 mm

Diameter: 2.53 mm

50 Ω stripline

50 Ω coaxial wave guide

L

Figure 2: The monopoles are fed by a coaxial guide drilled throughthe ground.

well-known scattering effects on the ground plane edgesalter the radiation pattern [7–9] (Figure 3). First of all,the interferences induce maxima and minima field on theradiation pattern. Their angular position is obviously relatedto the ground plane size. Then, we can observe the classicbeam deviation in the elevation plane, which is caused by thescattering on the edges of the limited ground plane, since themain beam direction does not coincide with the horizon. Toachieve the objective radiation pattern (we defined an angleθ = 75◦), we apply the array factor (2) with

k0 · d · sin(θ) + ϕi = m · 2 · π =⇒ ϕi = 203◦. (5)

It should to be stressed that these results are approximationssince the analysis considers the monopoles do not interferewith each other. The radiation pattern illustrated in Figure 4(monopole x-array factor) can be used as the objectiveradiation pattern φobj. In the next step, we have used CSTMicrowave studio to achieve the full-wave analysis of thewhole antenna structure. As an example, only 3 monopoleradiation patterns are plotted in Figure 3.

According to (1), the weights β are deduced and writtenin Table 1. Thus, Figure 4 points out the resemblancebetween the objective radiation pattern and the linear com-bination of the radiation patterns of monopoles weighted bythe coefficients β.

Figures 5 and 6 show the scattering matrix of themonopole antenna. Regarding Figure 6, these interactionsshould not be omitted when connecting the array monopoleswith the feed network. The coupling between nearbymonopoles is greater than −13 dB.

The optimum weights (ai) and the input impedances(Zref i) which simultaneously perform the objective radiation

International Journal of Antennas and Propagation 3

−15−12−9−6−3

0

3

6

9

−180 −120 −60 0 60 120 180

dB

Directivity (ϕ = 90◦)

Monopole1

Monopole6Monopole12

θ

Figure 3: Radiation patterns of monopoles when the monopolesare successively fed.

−9−6−3

0

3

6

9

12

15

−180 −120 −60 0 60 120 180

dB


Linear combination (Eq.1)

θ

Monopole ∗ array factor (objective)

Figure 4: Comparison of the objective radiation pattern (radiationpattern of monopole x-array factor) with the linear combination ofthe radiation patterns of monopoles ( f = 5.6 GHz).

−15

−12

−9

−6

−3

0

5.4 5.5 5.6 5.7 5.8

dB

Frequency (GHz)

S2,2S3,3S4,4

S5,5S6,6

Figure 5: Some Sii parameters of the array of monopoles.

−15

−14

−13

−12

−11

−10

−9

5.4 5.5 5.6 5.7 5.8

dB

Frequency (GHz)

S1,2S5,6

S7,6S11,12

Figure 6: Some Si j parameters of the array of monopoles.

Figure 7: The feed network is designed to maximize the efficiencyof the strongly coupled monopoles.

and the matching of all the feeding ports can be calculatedusing (3), (4), the scattering matrix [S], and the β vector.These values are given in Table 1 (columns 4 and 5) with theoptimized monopole lengths. These have been set to complywith the different impedance values resulting from thesynthesis procedure and to minimize the feed distributionnetwork complexity.

The design of the microstrip feed network has beenmade with the Agilent ADS software in order to performthe weights and the impedance matching specified in Table 1.The realized feed network is shown in Figure 7.

In order to perform the numerical validation, themonopole simulation and the feed network design arenumerically connected together. Using the CST software,this entire structure simulation provides the performancesof the whole array antenna (the 12 monopoles and the feednetwork). The radiation pattern, the gain, and the returnloss are computed. Figure 8 plots the radiation pattern inthe plane phi = 90◦. This is the plane which is parallel tothe array alignment. We can observe that the entire structuresimulation agrees very well with the objective radiationpattern (linear combination of the radiation patterns of themonopoles). So, the feed network operates properly throughthe couplings. Figure 9 presents the radiation pattern in 3Dat 5.6 GHz; the maximum simulated directivity is 15.6 dB.The main beam direction does not coincide with the horizon(θ = 90◦); it will be necessary to compensate this deviationby an inclination of the whole antenna. Indeed, it is essentialfor our application that the maximum gain is radiated in thebase stations direction.


Table 1: Normalized incident waves and reference impedances which optimize the efficiency of the array antenna for a specified radiationpattern (5.6 GHz).

MonopolesLength(mm)

β (= weights for the coupled radiation patterns)Normalized incident waves (ai) and antenna

impedances (Zref i) that optimize the efficiency

ai Zref i

1 10.8 0.286 · exp(− j∗48◦) 0.288 · exp(− j∗49◦) 29 + j∗132 9.8 0.293 · exp( j∗155◦) 0.30 · exp( j∗152◦) 32 + j∗103 9.3 0.279 · exp(− j∗3◦) 0.286 · exp(− j∗6◦) 31 + j∗94 9.3 0.284 · exp(− j∗155◦) 0.291 · exp(− j∗146◦) 30 + j∗15 9.3 0.284 · exp( j∗47◦) 0.287 · exp( j∗35◦) 27− j∗26 8.8 0.280 · exp(− j∗120◦) 0.283 · exp(− j∗124◦) 29 + j∗7.57 8.8 0.266 · exp( j∗82◦) 0.262 · exp( j∗79◦) 24 + j∗8.58 8.8 0.264 · exp(− j∗74◦) 0.251 · exp(− j∗77◦) 20 + j∗8.59 8.8 0.254 · exp( j∗131◦) 0.227 · exp( j∗124◦) 15 + j∗310 8.8 0.275 · exp(− j∗24◦) 0.257 · exp(− j∗35◦) 18− j∗1.511 8.8 0.319 · exp( j∗180◦) 0.323 · exp( j∗165◦) 28− j∗712 8.3 0.361 · exp( j∗0◦) 0.377 · exp( j∗0◦) 48 + j∗17

−9−6−3

0

3

6

9

12

15

−180 −120 −60 0 60 120 180

dB


Bac

kwar

d ra

diat

ion

Bac

kwar

d ra

diat

ion

θ

Linear combination of the element pattern (Eq.1)Entire structure simulation (feed networkconnected with the monopoles)

Figure 8: Simulated radiation pattern (directivity) comparison atf = 5.6 GHz.

The return loss at the input of the feed network is plottedin Figure 10 (simulation). The level is lower than −15 dBover the operating frequency bandwidth. This numericalvalidation shows that the radiation pattern is successfullysynthesized as well as the impedance matching of everyantenna port through the couplings. Although the feednetwork has been optimized to deal with the antennacouplings at 5.6 GHz, we have evaluated the performances ofthe entire structure (12 monopoles connected with the feednetwork) from 5.47 GHz to 5.725 GHz.

The antenna gain is 14.7 dB over the 5.47 GHz–5.725 GHz operating bandwidth (Figure 11). The directivityand the gain difference are mainly due to the dielectric lossesin the strip line circuit.

2.3. Measurements. The array of monopoles and the feednetwork were manufactured (Figures 1 and 7). The feed

15.6

10.1

6.44

2.760

−7.17−12.9

X

Y

Z

θ

−18.6−24.4

dBi

Output = directivityFrequency = 5.5975Rad. effic. = 0.8406

Dir. = 15.63 dBiTot. effic. = 0.8362

ϕ

Figure 9: Simulated radiation pattern in 3D (directivity) at f =5.6 GHz.

network is glued back to the ground plane and screws wereadded to secure the RF contacts. We have checked thatinteractions between the screws and the circuit are negligible.An SMA connector is at the input port.

Measurements were achieved in an anechoic chamber.The return loss of the tested antenna is in Figure 10(measurement). This measurement is compared with thesimulation: both S11 are close to −15 dB over the operatingfrequency bandwidth. A slight discrepancy of 50 MHz canbe observed compared to the simulation, but it representsonly 0.9% of the frequency shift that can be due to themesh accuracy during simulation or manufacture tolerance.Figure 12 compares the measured radiation pattern with the


−35−30−25−20−15−10−5

0

5.4 5.5 5.6 5.7 5.8

dB

Frequency (GHz)

Simulated S11Measured S11

Figure 10: Comparison of the S11 of the entire structure simulation(12 monopoles connected with the feed network) with the realizedstructure.

14

14.25

14.5

14.75

15

15.25

15.5

15.75

16

5.4 5.5 5.6 5.7 5.8

dB

Directivity

Gain

Frequency (GHz)

Figure 11: Directivity and gain versus the frequency (θ = 75◦, ϕ =90◦).

0

3

6

9

12

15

0 60 120 180

dB

Simulation

Measurement

Bac

kwar

d ra

diat

ion

Bac

kwar

d ra

diat

ion

θ

−9−6−3

−180 −120 −60

Gain (ϕ = 90◦)

Figure 12: Comparison of the objective radiation pattern simulatedwith the radiation pattern measured at f = 5.6 GHz.

67 mm

67 mm

335 mm

325 mm

67 mm

Z

X

Y

Figure 13: Array of 4 × 12 monopoles designed with CST Mwsseparated by 0.45 λ0 along [oy] and 1.25 λ0 along [ox].

67 mm

67 mm

67 mm

Input 50 Ω

divider

divider

divider

3 dB power

3 dB power

3 dB power

Figure 14: The feed network is designed to the four-subarrayantenna.

theoretical one over 360◦ in the plane of the array alignment(ϕ = 90◦). The measured gain agrees very well with theprediction. We can conclude that the design is reliable. Thefeed network operates properly through the couplings. Thedifferences between the simulated and the measured gainsare lower than 0.5 dB. Metallic losses in the feed networkand the uncertainty accuracy of our anechoic chamber canbe responsible for this discard.

3. 2D Array of 4× 12 Monopoles (4 Subarrays)The well-behaved experimental results validate the principleof the 12-monopole linear array. The linear array of twelvemonopoles (along [oy]) provided a gain of 14.7 dB at5.6 GHz. Figure 9 shows that the radiation pattern containslow side lobes in the perpendicular plane [ox] to the arrayof monopole plane alignment [oy]. In order to increasethe gain, a 2D array of 4 × 12 monopoles was designed(Figure 13). Four sub-arrays, where each of them is describedin Section 2, have been used to make the 48-monopole array.Therefore, the 4 sub-arrays are 1.25 λ0 spaced out in order toavoid the interferences in these directions. Obviously, thesesub-arrays alignment allow the constructive interference andso increase the gain in the end-fire direction.


−40

−30

−20

−10

0

5.4 5.5 5.6 5.7 5.8

dB

Frequency (GHz)

Figure 15: Modulus of S11.

20.8

15.9

11

6.1

0

−5.66−10.2

X

Y

Z

−14.7−19.2

dBi

θ

Output = directivityFrequency = 5.5975Rad. effic. = 0.8759

Dir. = 20.76 dBiTot. effic. = 0.8602

ϕ

Figure 16: Simulated radiation pattern in 3D (directivity) of 4× 12monopoles at 5.6 GHz.

3 dB power dividers have been designed to connect thefeed networks. 1.25 λ0 (67 mm) is sufficient in order to avoidthe interferences between the lines of the feed network.The corresponding layout of the feed network of 4 × 12monopoles is shown in Figure 14. The return loss at the inputof the feed network is plotted in Figure 15. The level is lowerthan −15 dB over the operating frequency bandwidth. The3D (Figure 16) radiation pattern shows a very directive lobe.A 20.8 dB maximum directivity is obtained at the end-firedirection. An increase of 5.2 dB has been obtained comparedto the case with a single subarray (12 monopoles) (Figure 9).The antenna gain is 20 dB over the 5.47 GHz–5.725 GHzoperating bandwidth (Figure 17). The directivity and thegain difference are mainly due to the dielectric losses inthe strip line circuit. Indeed, the insertion losses are verylow because the antenna reflection coefficient is lower than−15 dB over the 5.47 GHz–5.725 GHz band (Figure 15).

The 4 ×12 monopoles are sufficient to have the gainrequired in the specifications. The antenna was 15◦ tilted togive back the main beam deviation caused by the scatteringat the ground plane edges.

19.5

19.75

20

20.25

20.5

5.4 5.5 5.6 5.7 5.8

dB

Gain (ϕ = 90◦)

Frequency (GHz)

Figure 17: Gain versus the frequency (θ = 75◦, ϕ = 90◦).

330 mm100 mm

DirectorsDriver

35 mm

Reflector

Figure 18: Proposed Yagi antenna.

4. Yagi Antenna

In order to check the interest to develop the complete methodfor the conception, we have made another antenna. Theproposed antenna is a Yagi-Uda antenna.

Yagi antennas of three or more elements are widelyused, although a thorough study is lacking today because ofthe many parameters, each element having three variables,length, spacing, and the diameter of conductor. Almost allmultielement Yagis are invariably designed empirically. In[10], Yagi antenna of three elements was presented. It hasbeen shown the gain over a half-wave dipole of a threeelement Yagi with various director lengths and spacing. Thisstudy shows that as the spacing between director and driverdecreases, the optimum length of the director increases.

It has been documented in [11–13] that the dimensionratio of the reflector to the driven element can be somewherebetween 1.1 and 1.3. The dimension ratio of the director tothe driven element can be between 0.8 and 0.95. The distancebetween the centers of the reflector and the driven elementshould be about 0.25 free-space wavelengths, while theseparation between the centers of the director and the drivenelement and the separation between the directors themselvesshould be between 0.3 and 0.4 free-space wavelengths.

The antenna characteristics such as gain, front-to-backratio, beamwidth, and center frequency can be altered bychanging the length of the driven element, the length of theparasitic elements, spacing between reflector and dipole, andspacing between director and dipole [14].


−20

−15

−10

−5

5.2 5.4 5.6 5.8 6

dB

0

5

Frequency (GHz)

Figure 19: S11 of the Yagi antenna.

14.4

10.8

7.18

3.59

0

−6.41−12.8

XY

Z

θ

(dBi)

−19.2−25.6

Output = directivityFrequency = 5.5975

Dir. = 14.37 dBi

ϕ

Rad. effic. = 0.01509 dBTot. effic. = −0.03811 dB

Figure 20: Simulated radiation pattern in 3D (directivity) of Yagiantenna at 5.6 GHz.

The proposed antenna consists of a monopole as adriven element, a reflector, and eleven directors as shown inFigure 18. To facilitate the design, this antenna is designedusing the same size of the prototype described in Section 2.Since our application requires only one high-gain radiationdirection, it is proceeded to prohibit the radiation inthe half space behind the antenna. The backfire radiationcan be avoided with some non excited elements named“reflectors” or with a vertical metallic plane. Intended forsimplicity constraints, the second solution is selected. So, thedriver monopole must be spaced out of a λ0/4 (13.4 mm)distance from the reflector plane. This separation allows aconstructive interference between the reflected fields and thedirect waves. In this case and according to the images theory,the antenna gain should be 3 dB increased at the end-firedirection.

The separation between the centers of the director andthe driven element and the separation between the directorsthemselves is 0.45 free-space wavelength (24.12 mm). Thedirector lengths are 6.7 mm (λ0/8) and their diameters are

67 mm

67 mm

67 mm

335 mm

325 mm

Figure 21: Array of 4×Yagi antenna.

18.6

13.9

9.28

4.64

0

−5.36−10.7

X Y

Z

−16.1−21.4

(dBi)

Side lobes

θ

Output = directivityFrequency = 5.5975

Dir. = 18.56 dBi

ϕ

Rad. effic. = 0.006677 dBTot. effic. = −0.0915 dB

Figure 22: Simulated radiation pattern in 3D (directivity) of4×Yagi antenna at 5.6 GHz.

2.53 mm. These directors are shortcircuited with the groundplane. The length of the driver monopole is 10.32 mm; itsdiameter is 4.53 mm.

The yagi antenna is matched to −18 dB in simulationover a bandwidth 5.47 GHz–5.725 GHz (Figure 19). Thesimulated radiation pattern in 3D is presented in Figure 20;the maximum directivity is 14.3 dB at the end-fire direction.

In order to increase the directivity, a 2D array of4×Yagi antenna was designed (Figure 21). The antenna wasdesigned using the same size of the prototype described inSection 3 to make a true comparison between the array ofmonopole antenna and the Yagi antenna. Figure 22 presentsthe radiation pattern at 5.6 GHz. We obtain a maximumdirectivity of 18.5 dB. The comparison of radiation in theCartesian plane between the array of monopoles and theyagi antenna is shown in Figure 23. The radiation pattern iscompared versus ϕ at θ = 75◦ (maximum radiation). We canobserve the first side lobe level of yagi radiation pattern isaround 12 dB; it is−6 dB below the main lobe which explainsthe maximum directivity of yagi antenna is 2.3 dB lower thanthe radiation of the monopole array.


−12−9−6−3

0369

12151821

−180 −120 −60 0 60 120 180

dB

Directivity (θ = 75◦)

Monopole antennaYagi antenna

ϕ

Side lobes2.3 dB

Figure 23: Comparison of the radiation pattern of 4 × 12 monop-oles with the 4×Yagi array antenna.

The advantages of the monopole antenna compared tothe Yagi antenna are

(1) the array of monopole antenna designed in Section 3does not need to a reflector plane to radiate on theend-fire direction,

(2) the radiation pattern of monopole antenna does notcontain significant side lobes levels,

(3) the maximum level of radiation of the monopolesantenna is greater than the yagi,

The disadvantages of the monopole antenna compared tothe Yagi antenna is the feed network.

5. Conclusion

In this paper, a low-profile antenna with a ground planehas been presented. The purpose was to design a high-gainantenna (single end-fire beam) which must be positionedon a vehicle roof in order to communicate with the farbase stations. As a first step, an array of 12 monopoleswas designed. In such a structure, the monopoles stronglyinteract with each other.

In our study, the feed network has been designed todeal with the couplings by considering as a reference theimpedances and the input waves that optimize the efficiencyof the antenna.

The feed network and the monopole array were man-ufactured. The whole antenna was successfully tested. Theantenna was tilted to give back the main beam deviationcaused by the scatterings on the ground plane edges.

As a second step, an array of 4 × 12 monopoles has beendesigned in order to increase the gain. A gain higher than20 dB has been achieved over a 4.5% bandwidth.

Finally, in order to check the interest to develop thecomplete method for the conception, we have made anotherantenna. The proposed antenna is a Yagi-Uda antenna. Theradiation of this antenna presents high side lobe levels.The maximum radiation on the end fire is lower than

the radiation of the monopole array. In conclusion, as themethod takes into account couplings, a particular beampointing with reduced or controlled side lobes can beachieved easily.

References

[1] B. Tomasic and A. Hessel, “Linear array of coaxially fedmonopole elements in a parallel plate waveguide-I: theory,”IEEE Transactions on Antennas and Propagation, vol. 36, no.4, pp. 449–462, 1988.

[2] D. M. Pozar, “The active element pattern,” IEEE Transactionson Antennas and Propagation, vol. 42, no. 8, pp. 1176–1178,1994.

[3] J. P. Daniel and C. Terret, “Mutual coupling between anten-nas optimization of transistor parameters in active antennadesign,” IEEE Transactions on Antennas and Propagation, vol.AP-23, no. 4, pp. 513–516, 1975.

[4] A. K. Bhattacharyya, Phased Array Antennas: Floquet Analysis,Synthesis, BFNs, and Active Array Systems, John Wiley & Sons,Hoboken, NJ, USA, 2006.

[5] R. J. Mailloux, Electronically Scanned Array. Synthesis Lectureon Antennas, Morgan & Claypool Publishers, ConstantineBalanis, Ariz, USA, 2007.

[6] J. Drouet, M. Thevenot, R. Chantalat et al., “Global synthesismethod for the optimization of multi feed EBG antennas,”International Journal of Antennas and Propagation, vol. 2008,Article ID 790358, 6 pages, 2008.

[7] S. K. Sharma and L. Shafai, “Beam focusing properties ofcircular monopole array antenna on a finite ground plane,”IEEE Transactions on Antennas and Propagation, vol. 53, no.10, pp. 3406–3409, 2005.

[8] C. Phongcharoenpanich, S. Suriya, T. Lertwiriyaprapa, P.Ngamjanyaporn, and M. Krairiksh, “Analysis of circular arrayof monopole on the ground plane radiating linearly polarizedconical beam for wireless LAN applications,” in Proceedings ofthe 5th International Symposium on Antennas, Propagation andEM Theory, pp. 646–649, Beijing, China, August 2000.

[9] V. Volski and G. A. E. Vandenbosch, “Modelling of microstripantennas on a finite ground plane using the 2D physical opticsmodel,” Microwave and Optical Technology Letters, vol. 40, no.1, pp. 26–29, 2004.

[10] H. Jasik, Antenna Engineering Handbook, McGraw-Hill BookCompany, New York, NY, USA, 1961.

[11] J. Huang and A. C. Densmore, “Microstrip Yagi array antennafor mobile satellite vehicle application,” IEEE Transactions onAntennas and Propagation, vol. 39, no. 7, pp. 1024–1030, 1991.

[12] H. Yagi, “Beam transmission of the ultra short waves,” IREProceedings, vol. 16, no. 6, pp. 715–740, 1928.

[13] C. A. Balanis, Antenna Theory. Analysis and Design, John Wiley& Sons, New York, NY, USA, 1997.

[14] S. K. Padhi and M. E. Bialkowski, “Parametric study of amicrostrip Yagi antenna,” in Proceedings of the Asia-PacificMicrowave Conference, pp. 715–718, Sydney, NSW, Australia,December 2000.

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttp://www.hindawi.com Volume 2010

RoboticsJournal of

Hindawi Publishing Corporationhttp://www.hindawi.com Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation http://www.hindawi.com

Journal ofEngineeringVolume 2014

Submit your manuscripts athttp://www.hindawi.com

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation http://www.hindawi.com

Volume 2014

The Scientific World JournalHindawi Publishing Corporation http://www.hindawi.com Volume 2014

SensorsJournal of


Modelling & Simulation in EngineeringHindawi Publishing Corporation http://www.hindawi.com Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks


Date post:	10-Feb-2021
Category:	Documents
Upload:	others
View:	1 times
Download:	0 times

HighGainArrayofMonopoles-CoupledAntennasfor ...International Journal of Antennas and Propagation 3...

Documents