27096d1192166774-cst_application_note__periodic_arraysfss_pbg__1052.pdf

8/9/2019 27096d1192166774-cst_application_note__periodic_arrays__fss___pbg__1052.pdf

1/25

1

Frequency SelectivUnit CellComplimentary Arr

Tips + TricksMetamaterialsDispersion Diagram

CST STUDIO SUITE 2006BApplication Note

Perodic Arrays : FSS / PBG /

mja / v1.0 / 09. Nov 2006


2/25

2

Periodic Arrays

Frequency Selective Surfaces (FSS)?

Periodic assemblies of identical elements arranged in a or two-dimensional array.

These periodic structures are either an array of aperturea thin metallic sheet or metallic patches on a diesubstrate

D x

D y

w

Rint g

s


3/25


4/25

4

Conducting and Aperture Arrays

Complimentary Arrays

Combination of conducting and aperture arrays of sshape when put one on top of each other forms a comp

perfectly conducting plane

Band Stop Band


5/25

5

Typical FSS Elements

Single polarelements

Dual polarelements

Resonant wavelength r for element without substrate

Dipoles = l/2

Rings=2 (Rin + 0.5w)

With a substrate the resonant wa

= r r


6/25

6

The Unit Cell

Dx )

Dy

u

The unit cell can be defined as the basic buildingblock (can be an arbitrary resonant shape) of thearray that repeats itself infinitely defined by theperiodicity Dx, Dy and the angle in-between


7/25

7

Passive and Active Arrays

Methods of Excitation

Fundamentally any periodic array can be excited inways:

Incident Plane wave i (passive array)

Individual Generators connected to each ele(active array)

For an active array the voltage generators must have thesame amplitude and a linear phase variation across the acarray in order to qualify as a periodic array


8/25

8

CST MWS Example ( F So


9/25

9

Floquet Ports


10/25

10

Unit Cell Boundaries

Unit cell boundaries allowplane waves at arbitrary angles


11/25

11

Plane Wave Incidenceat arbitary Angles


12/25

12

Transmission CoefficientIn-band (transmission through)

Out of band ( No transmission) Out of band ( No transmission)

resonance 2 resonance

S p a r a m e

t e r m a g n

i t u

d e

( d B )

E field animation at 1GHz E field animation at 10GHz

RingResonator_FrequencyDomain.zip


13/25

13

Coupling Modes & Casacaded Array

Cascaded aBW and theto control th

E

E

E

Coupling TE and TM modes by nesting rings allowfor dual polar dual frequency filters to be designed


14/25

14

Unit Cell ( T Solver )

Unit cell withwaveguide ports

RingResonator_TimeDomain.zip


15/25

15

Metamaterials

AMC

LH

D

PBG

EBG

(Artificial MagneticConductor)

(Doub

(Left HandedElectromagnetic Bandgap

(Photonic Bandgap)


16/25

16

AMC

PEC: reflect incident waves with 180o

phase sPMC : Would reflect waves with 0 o (dual)

S

Source

PRS

Direct wave

Reflected wave

1

2

PEC

S

Source

PRS

Direct wave

Reflected wave

1

2

PEC

S

Source

PRS

Direct wave

Reflected wave

1

2

PEC

- Direct wave 1- Reflected wave

Transmissionphaseof the FSS

Phasedelayalong S

ReflphasPEC

Resonance Condition:

2 = 2 T - 2 2S

2 1 = 2 T - 2

An AMC can be generated by having a ground planclose proximity to the FSS. The combination provid0 phase shift from the reflected wave


17/25

17

Plane Wave Incidence ( T S

0 phase AMC region

Incident plane waveonto a unit cell(difference betweenphase diagram with

and without AMCstructure)

probe


18/25

18

EBG and PBG

EBG are the Electromagnetic equivalent of Photonic Gaps (PBG). PBG are dielectric structures with a forbgap for electromagnetic waves.

Surface waves on a periodic array are suppressed propagating at the band gap frequency

Dispersion diagrams can be used to identify EBGregions


19/25

19

Unit Cell Modelling ( E Sol

Periodic boundary condition

model the whole crystal strucZ axis boundaries are either

in order to obtain TE and TM


20/25

20

Dispersion Diagram

Each third of the overall dispercan be reproduced by plottEigen solutions againstcondition phases

Eigen mode solver parametersweep is used to stepthrough the phase assignedto the periodic boundaries

Band Gap


21/25

21

LHM

All transparent or translucent materials that we knpossess positive refractive index

Materials with simultaneously negative frequently referred to as left handed, negative refr

index and double negative materials

In these materials, the group velocity and phase velare anti-parallel

Artificially structured materials mimic the negativeSRR and the negative by an array of conductwhere the unit cell dimensions are


22/25

22

LHM Split Ring Resonator

An edge-coupled SRR design withwaveguide ports

Port excitation from left to right bphase propagation in the SRR region

Application note on the web (http://www.cst.com/Content/Articles/article246.aspx)


23/25

23

Summary

Passive and Active FSS arrays exhibit band stoppass filter responses

T solver with E and H boundaries (and waveguide can be used to model 0 degree incidence

F solver with unit cell boundaries allow arbitrary anincidence with Plane wave incidence

Unit cell with appropriate boundary conditions alaccurately model an infinite periodic array

E solver with periodic boundaries is used to step ththe phase assigned to the periodic boundaries to solve the Eigen modes against phase


24/25

http://www.edatop.com

(www.edatop.com)

2006 EDA (www.mweda.com)

ADS HFSS

http://www.edatop.com/peixun/rfe/129.html

30 3

http://www.edatop.com/peixun/rfe/110.html

ADS

ADS 10 ADS

ADS

ADS

ADS

ADS ADS ...

http://www.edatop.com/peixun/ads/13.html

HFSS

HFSS

HFSS HFSS

3

HFSS

http://www.edatop.com/peixun/hfss/11.html

`


25/25


CST

EDA

CST

CST

3

http://www.edatop.com/peixun/cst/24.html

HFSS

6 1

HFSS

HFSS

HFSS http://www.edatop.com/peixun/hfss/122.html

13.56MHz NFC/RFID

4 13.56MHz

13.56MHz

HFSS CST

13.56MHz

13.56MHz

http://www.edatop.com/peixun/antenna/116.html

2004 10


EDA http://www.mweda.com

http://shop36920890.taobao.com


Date post:	01-Jun-2018
Category:	Documents
Upload:	pham-tuyen
View:	218 times
Download:	0 times

27096d1192166774-cst_application_note__periodic_arrays__fss___pbg__1052.pdf

Documents

27096d1192166774-cst_application_note__periodic_arraysfss_pbg__1052.pdf