Microwave Circuits and Components. Design, Analysis, Optimisation

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1 Microwave Circuits and Components Design, Analysis, Optimisation

2 Circuits and Components Power dividers Directional couplers Biasing, matching networks Lumped components Active components Electro-mechanical Connectors transitions Filters Diplexers

3 Microwave Circuit Design Flow Math & circuit representation 3D model System environment optimisation

4 Outline Multi-step design of directional couplers Filter tuning/optimisation Dispersive properties of materials EM/circuit co-simulation RFID system simulation

High-Power Directional Coupler Specifications Frequency Band: 800 2200 MHz Return Loss: <-20 db Isolation: <-23 db

5 High-Power Directional Coupler Specifications Frequency Band: MHz Return Loss: <-20 db Isolation: <-23 db Insertion Loss, Coupling: -3.0±0.3 db N-type connectors The picture and measured data provided with courtesy of C-Com s.r.o.

6 Ideal 2-Sectional Directional Coupler

about the differential and common mode line impedance.

7 Coupled TL Cross-Section A-A B-B A-A B-B Zd1=Zo1*2 Zc1=Ze1/2 Zd2=Zo2*2 Zc2=Ze2/2 Multipin waveguide ports provide information about the differential and common mode line impedance. The coupled line cross-section is optimized using Zd and Zc from post-processing template.

8 Equalization of Differential and Common Mode Phase Velocity Capacitors and geometry modification of the 3D transition are used for the phase velocity compensation of DM and CM. CM DM

9 Design by Parts nd 1 st 3 rd

10 Final 3D Model Assembly Mode

11 Measured Performance (1) S31 - Insertion loss S21 - Coupling

12 Measured Performance (2) 2 1 h 4 3 S33 - Return loss S23 - Isolation

13 yield Yield Analysis 99 % ±0.06 mm

Filter Tuning / Optimisation Difficult task Many variables Complex goal function High sensitivity Tuning techniques Direct 3D EM optimisation

14 Filter Tuning / Optimisation Difficult task Many variables Complex goal function High sensitivity Tuning techniques Direct 3D EM optimisation Space mapping techniques Trust region framework Special techniques Group delay Inverse chirp Z transformation Example: Planar filter S2 L1 L2 L3 S1

15 Direct 3D EM Optimisation After 620 EM simulations

16 Trust Region Framework + Sensitivity

17 TRF + Sensitivity: Results

18 Multiphysics Filter Simulation EM-field computation Thermal analysis Stress analysis / deformation EM-properties of deformed geometry can be fed into sensitivity analysis

19 Complex Permittivity Extraction ε r ε r

20 3D EM/Circuit Co-Simulation Standard (via S-matrix) Linear (S-parameter task) Non-linear (Spectral line harmonic balance) True Transient Update each time step of EM simulator Arbitrary waveforms Transient field behaviour Direct coupling to the non-linear components

21 SRD Pulse Generator Update of V and I in the circuit at every time step of EM simulator. Step-recovery diode By courtesy of Czech Technical University in Prague

22 Voltage [V] SRD Pulse Generator Results Simulation Measurement Time [ns] By courtesy of Czech Technical University in Prague

23 Frequency Doubler 5 9 GHz Input (1f) Output (2f) x2 Simulation Measurement By courtesy of Czech Technical University in Prague

24 Example: System Simulation How is the read range affected if the tag is placed among a group of other tags? Will the transmission to each still be sufficient? Tag reader, optimized for operation at 900 MHz.

25 Magnetic Field Transmission

26 System View: AM-Signal Generator HF Signal AM Input Signal at RFID Reader Input Signal LF Signals at RFID Tag 3

modeling Sophisticated optimisation System simulation

27 Conclusions Complete technology DC + power splitters Filters Connectors, transitions Advanced material modeling Sophisticated optimisation System simulation 3D assembly mode Multiphysics simulation EM/circuit co-simulation

EM/Circuit Co-simulation Vratislav Sokol

EM/Circuit Co-simulation Vratislav Sokol 1 UGM 2009, Wednesday 18 th March, Darmstadt www.cst.com Agenda Motivation for EM/Circuit Co-simulation Standard versus Transient Co-simulation Standard Co-simulation