SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE SIMULATION OF WAVEGUIDE

CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS CIRCUITS AND ANTENNAS

WITH MMTWITH MMTWITH MMTWITH MMTWITH MMTWITH MMTWITH MMTWITH MMT--------BASED BASED BASED BASED BASED BASED BASED BASED

MODULAR SOFTWAREMODULAR SOFTWAREMODULAR SOFTWAREMODULAR SOFTWAREMODULAR SOFTWAREMODULAR SOFTWAREMODULAR SOFTWAREMODULAR SOFTWARE

Dept. Computational ElectromagneticsInstitute for Radio-Physics and Electronics NASU

Kharkov, Ukraine

A. Nosich

with inputs from A. Kirilenko and L. Rud

Examples of simulated waveguide circuits

Main ideas and parts1.1. Segmentation:Segmentation: decompose any decompose any

waveguide circuit into a sequence of waveguide circuit into a sequence of

regular segments of simple and multiregular segments of simple and multi--

connected waveguides,connected waveguides,

2.2. Modes: Modes: find vector modal base of each find vector modal base of each

segment,segment,

3.3. Matching: Matching: join segments via plane join segments via plane

junctions and calculate corresponding junctions and calculate corresponding

SS--matrices,matrices,

4.4. Assembling:Assembling: build the Sbuild the S--matrix of the matrix of the

whole circuitwhole circuit

Example of simulated filter configuration

SegmentationSegmentationSegmentation

Longitudinal segmentation

1.1. Reveal possible Reveal possible symmetriessymmetries,,

2.2. Determine Determine connectivityconnectivity of crossof cross--

sections,sections,

3.3. Introduce Introduce virtual segmentsvirtual segments of zero of zero

lengths,lengths,

4.4. Determine domains of Determine domains of overlappingoverlapping of of

the crossthe cross--sections of segments joint at sections of segments joint at

plane junctionsplane junctions

3D graphic editor based on AutoCADwire model. Example of editing

SegmentationSegmentationSegmentation

Search of modal bases

1.1. Split to Split to classesclasses of symmetry,of symmetry,

2.2. Introduce rectangular or circular subIntroduce rectangular or circular sub--

domains and domains and series expansionsseries expansions,,

3.3. Satisfy Satisfy matchingmatching conditions at subconditions at sub--

domain boundaries,domain boundaries,

4.4. Reduce the Reduce the eigenvalueeigenvalue problem to a problem to a

determinantdeterminant equationequation

5.5. If connectivity >1, findIf connectivity >1, find TEM modesTEM modes

from electrostatic problemfrom electrostatic problem

Modal basesModal basesModal bases

Electromagnetic solver interfaceAnalysis of the field patterns

Generalized S-matrices

For each junction:For each junction:

�� Input:Input: coordinates of overlapping coordinates of overlapping

domains,domains,

�� Method:Method: modemode--matching and matching and

coupling integrals,coupling integrals,

�� Output:Output: SS--matrix of a junction,matrix of a junction,

Final step: Final step:

automatic assembling of the full automatic assembling of the full

SS--matrix of the whole circuitmatrix of the whole circuit

3D graphic editor based on AutoCADSolid model

Plane junctionsPlane junctionsPlane junctions

Overall SOverall SOverall S---matrixmatrixmatrix

Electromagnetic solver interfaceAnalysis of the filter characteristics

EvanescentEvanescent--mode mode bandpassbandpass filtersfilters on singleon single-- and and doubledouble--ridged waveguidesridged waveguides

Improved stop Improved stop

band performanceband performance

Filters

Filters - interface

Specification windowFilter geometryFrequency responsesParasitic bandwidths analysis

EvanescentEvanescent--mode lowmode low--pass filter configurations and pass filter configurations and performance of an 11performance of an 11--pole doublepole double--ridge filterridge filter

Filters

Bandwidth

26-40 GHz

BandstopBandstop filters on the Efilters on the E--plane stubsplane stubs and and characteristics of a 5characteristics of a 5--pole filterpole filter

Filters

Mode converter

TETE1010→→TTEEn0n0 mode converter built on the Hmode converter built on the H--plane nonsymmetrical plane nonsymmetrical

truncated angled bend truncated angled bend ((input waveguideinput waveguide 2323хх10 10 mmmm))

Square waveguide

polarizer

NarrowNarrow--band polarizer built on a square waveguide with band polarizer built on a square waveguide with

squaresquare--corner cuts and its characteristicscorner cuts and its characteristics

Circular waveguide polarizer with rectangular ridges and Circular waveguide polarizer with rectangular ridges and

characteristics of the optimized 4characteristics of the optimized 4--element polarizerelement polarizer

Circular waveguide

polarizer

DualDual--mode mode bandpassbandpass filtersfilterswithwith tilted rectangular coupling irisestilted rectangular coupling irises

4

-

6

-

8

-

pole

Filters

Filters

4-1 8-2

Frequency responses of the designed 4Frequency responses of the designed 4-- and 8and 8--pole pole

dualdual--mode bandmode band--pass filterspass filters

Vacuum window in

circular waveguide

Vacuum windows with one and two dielectric plates in a Vacuum windows with one and two dielectric plates in a

circular waveguide and their characteristicscircular waveguide and their characteristics

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5

1.00

1.02

1.04

1.06

1.08

1.10

VS

WR

Frequency, GHz

Waveguide28.5х12.6 мм

8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0

1.0

1.5

2.0

2.5

3.0

Theory

Measurement

Waveguide23.0х10.0 мм

VS

WR

Frequency, GHz

TE01

TE02

EE--plane bifurcation diplexersplane bifurcation diplexers

withwith oneone--step transitionstep transition

Diplexers

HH--plane bifurcation diplexersplane bifurcation diplexers

withwith oneone--step transitionstep transition

Diplexers

EE--tee based diplexerstee based diplexers

Diplexers

HH--tee based diplexerstee based diplexers

Diplexers

Diplexers

Frequency responses of the designed EFrequency responses of the designed E--tee based diplexer and tee based diplexer and

channel filters on symmetrical inductive iriseschannel filters on symmetrical inductive irises

Crossed slot coupler

CrossCross--slot coupler (Moreno coupler) and its characteristics for slot coupler (Moreno coupler) and its characteristics for

varying thickness of irises varying thickness of irises tt and angles of their rotation, and angles of their rotation, αα1,21,2

Multilayer lowpass filter

Multilayer lowMultilayer low--pass filter, waveguides whose mode bases have to pass filter, waveguides whose mode bases have to

be calculated during the filter analysis, and the filter responsbe calculated during the filter analysis, and the filter responses es

(black) compared with the moment method results (red)(black) compared with the moment method results (red)

1 2 3 4 5 6 7 8 9

60

50

40

30

20

10

0

|S11

|

|S21

||S11|, |S

21|, dB

Frequency, GHz

Dual-band septum

polarizer

DualDual--band septum polarizer and an example of its band septum polarizer and an example of its

characteristicscharacteristics

Dual-band orthomode

transducer

DualDual--band band orthomodeorthomode transducer and its characteristics transducer and its characteristics

within the Intelsat operation bandswithin the Intelsat operation bands

Dual-band corrugated

circular horn antenna

r

R

( )i

cb

( )i

ca

( )i

cg

( )i

ct

α

g t

( )n

ha( )n

hb

l

Fig. 1. Parameters of corrugated horn structure. Half of crossHalf of cross--section of a section of a

dualdual--band corrugated hornband corrugated horn

Antenna analysis:Antenna analysis:

•• Horn is considered as a Horn is considered as a

cascade of circular waveguide cascade of circular waveguide

junctionsjunctions

•• SS--matrices are determined matrices are determined

and assembled togetherand assembled together

•• Horn opens into a wide Horn opens into a wide

circular waveguide and circular waveguide and

radiation patterns are found by radiation patterns are found by

aperture integrationaperture integration

Dual-band corrugated

circular horn antenna

r

R

( )i

cb

( )i

ca

( )i

cg

( )i

ct

α

g t

( )n

ha( )n

hb

l

Fig. 1. Parameters of corrugated horn structure. Input dimensions: Input dimensions: rr=5 mm, =5 mm,

RR=27.5 mm, =27.5 mm, tt=0.4mm, =0.4mm,

NN1=4 slots in the throat and 1=4 slots in the throat and

NN2=25 slots in the flare 2=25 slots in the flare

sections, sections, αα=15deg=15deg

Antenna synthesis by numerical Antenna synthesis by numerical

gradients:gradients:

•• At first, return loss is minimized At first, return loss is minimized

over two operating bandsover two operating bands

•• Then, polarization purity and Then, polarization purity and

radiation pattern symmetry are radiation pattern symmetry are

tuned to prescribed valuestuned to prescribed values

•• Task example:Task example:TE11 mode incidence, horn bands: TE11 mode incidence, horn bands: 2020--21.5 GHz21.5 GHz & & 29.529.5--31.5 GHz31.5 GHz

inin--band return loss band return loss --25 dB, 25 dB,

peak peak XPolXPol --40 dB, pattern non40 dB, pattern non--uniformityuniformity

0.25 dB within 300.25 dB within 30--deg sectordeg sector

FarFar--field patterns and return loss vs. frequencyfield patterns and return loss vs. frequency

Dual-band corrugated

circular horn antenna

Conclusions

1.1. At IREAt IRE--KharkovKharkov, a modular full, a modular full--wave GMM software for the wave GMM software for the

waveguide circuits analysis, synthesis and optimization has waveguide circuits analysis, synthesis and optimization has

been developed since the 1980s.been developed since the 1980s.

2.2. This software can be adapted to the efficient and accurate This software can be adapted to the efficient and accurate

analysis and synthesis of certain types of antennas.analysis and synthesis of certain types of antennas.

3.3. The corrugated circular horn configurations that provide The corrugated circular horn configurations that provide

specified return loss, polarization purity, and radiation specified return loss, polarization purity, and radiation

pattern symmetry over 2 widely separated bands have pattern symmetry over 2 widely separated bands have

been demonstratedbeen demonstrated..

•• IEEE Trans. on MTT (IEEE Trans. on MTT (66))

•• Microwave and Optical Technology Letters (Microwave and Optical Technology Letters (44))

•• Int. J. RadioInt. J. Radio--Frequency and Microwave Computer Aided Frequency and Microwave Computer Aided

Engineering (Engineering (33))

•• J. Telecommunications Technology and ElectronicsJ. Telecommunications Technology and Electronics ((55))

•• Proc. European Microwave Conferences (Proc. European Microwave Conferences (1010))

•• IEEE MTTIEEE MTT--S Symposium Digests (S Symposium Digests (66))

•• Proc. Int. Polish Conferences on Microwaves and Radars (Proc. Int. Polish Conferences on Microwaves and Radars (77))

•• Proc. Int. Conferences Mathematical Methods in EM Theory (Proc. Int. Conferences Mathematical Methods in EM Theory (1515))

•• Proc. Int. Proc. Int. SympSymp. Physics and . Physics and EngnEngn. MM and Sub. MM and Sub--MM Waves (MM Waves (1616))

Relevant Publications on

Waveguide and Antenna Analysis,

Synthesis, and Design since 1994