Synthesis and Tuning of Modern Microwave Filters and Tuning of Modern Microwave Filters Vratislav...
Transcript of Synthesis and Tuning of Modern Microwave Filters and Tuning of Modern Microwave Filters Vratislav...
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Synthesis and Tuning of Modern
Microwave Filters
Vratislav Sokol, CST
CST – COMPUTER SIMULATION TECHNOLOGY | www.cst.com
Introduction – CST tools, Workflow
Planar filter synthesis (Nuhertz)
Planar filter tuning (BF/SM)
Cavity filter synthesis (Constr. macro)
Cavity filter tuning (BF/GD/invZ, SAM)
Examples
CST key features for the filter design
Conclusion
Agenda
Courtesy of C-COM Ltd.
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Construction macro
Cross-coupling
Automatic tuning (SAM)
CST Tools for Microwave Filter Design
NuHertz
Box resonances
Anisotropic dispersive
material properties
Planar Filters
Cavity Filters
Project Template
Arbitrary topology
Full 3D geometry
MOR/FEM solver
Optimizers (e.g. TRF)
Multiphysics (thermal
and mechanical)
Sensitivity and yield
All Structures
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Microwave Filter
Planar
Nuhertz Synthesis
Tuning Yield
General Design Input/Output
Coupling (Qext)
Interresonator Coupling
Tuning Yield
Cavity
Construct. Macro Tuning Yield
General Design Input/Output
Coupling (Qext)
Interresonator Coupling
Tuning Yield
Workflow
Type Synthesis Tuning Result
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Planar Filter Synthesis
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Nuhertz - Filter Quick
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Nuhertz Link to CST
layout
CST DS layout
CST MWS model
3D simulation results
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First-Iteration Filter
Parameters
Tuning
Prototype
Final design
b=572 m
il
S1=35 mil
S2=44 mil
L=435 mil
Tap= 91.6 mil
a= 512 mil
W= 50 mil goal
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Planar Filter – Tuning Parameters
Tuning
Prototype
Final design
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CMA Evolution optimizer
global optimizer
very good convergence
Example: Filter Optimization
S1
S2 L3
L2
L1
Frequency in GHz
|S11| i
n d
B
Excellent response
Parameters
Tuning
Prototype
Final design
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Trust Region Framework optimizer
local optimizer
can exploit sensitivity information
Example: Filter Optimization
Frequency in GHz
|S11| i
n d
B
Good result in fewer iterations
(20 x faster in this case)
Parameters
Tuning
Prototype
Final design
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Port-Tuning Technique
C1 ... L1, C2 ... L2
C3 ... L3, C4 ... S1
C5 ... S2
S-parameters of the filter
including discrete ports
Fast circuit
optimisation
of C1-C5
Update
L1-L3,
S1-S2
OK?
End
3D EM
1
2
3
4 5
See application note on support website!
Parameters
Tuning
Prototype
Final design
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TSM–Sensitivity Surrogate Model
'
2
'
1
'
3
'
2
'
111
'
11 2
11
1
11
3
11
2
11
1
11 SSLLLSSS
S
S
S
L
S
L
S
L
S
• CMA-ES Post-processing optimization on the surrogate model using virtual S-parameters.
• Only a few 3D EM simulations needed for getting the final filter response
Parameters
Tuning
Prototype
Final design
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Sensitivity Analysis
Parameters
Tuning
Prototype
Final design
Manufacturing tolerances can be taken into account using sensitivity analysis. A face
constraint should be defined for each tolerant parameter (e.g. metallization edges).
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97% of the filter samples satisfied the
specification assuming that the manufacturing
tolerance is 0.1 mil (3 x standard deviation).
Parameters
Tuning
Prototype
Final design
Yield Analysis
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Cavity Filter Synthesis
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3D Filter Macro Interdigital
Combline
Cavity
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Cavity Filter Tuning
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Direct 3D Optimization (CMA-ES)
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Problem: filter tuning requires many manual steps... Tuning of each cavity (peak) is “almost” independent.
Sequential problem!
SAM – Semi-Automatic Filter Tuning
Peak Time-Positions
Coupling elements
Peak Depths Tuning screws
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SAM – Semi-Automatic Filter Tuning
1
2
3
4
1 2
3 4
Run tuning steps in sequence iterate.
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Examples
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Tuning Space Mapping Technique
Courtesy of C-COM Ltd. (Published in RADIOENGINEERING,
VOL. 20, NO. 1, APRIL 2011)
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Low-Pass Filter 22.5 GHz
Microstrip Lowpass Filter on RO4350 Substrate
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Band-Pass Filter
Miniaturized High-Rejection Ku Band Planar Band-Pass Filter
for Satellite Applications
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CST Key Features
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Simulation Time Memory
FD - Gen Purpose 19 min 34 sec 2.2 GB
FD- MOR TET 6min 52 sec 3.8 GB
Model courtesy of
THALES ALENIA SPACE
Dr. Marcello Zolesi
FEM MOR Solver (Sensitivity)
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EM-field computation
Thermal analysis
Stress analysis /
deformation
Multiphysics Filter Simulation
EM-properties of deformed geometry can be fed into sensitivity analysis
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Complete technology for the filter design
Arbitrary filter topology including the X-coupling
Nuhertz link & 3D macro for the filter synthesis
Smart tuning techniques
Multiphysics for high power filters
Very good agreement between simulation and
measurement
Two ANs on filter design & tuning at support web page
Conclusion
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Thank you for your attention!
Any questions?