Multiphysics Simulation of a Monoblock Dielectric Filter

Transcription

1 Multiphysics Simulation of a Monoblock Dielectric Filter Theunis Beukman, CST AG

2 Overview Filter device Introduction Synthesis Optimization Multiphysics workflows High ambient temperature High input power Conclusion

3 Monoblock Filter Ceramic dielectric block with silver-plated coating, metal lid and tuning screws Dielectric block Compact size High Q-factor Thermal stability Desired properties for a modern communication system Metallization Filter based on publication: Xi Wang; Ke-Li Wu, "A TM01 Mode Monoblock Dielectric Filter," IEEE Transactions on Microwave Theory and Techniques, vol.62, no.2, pp.275,281, Feb

4 Filter Specifications f 0 = 2.6 GHz (center frequency) BW = 50 MHz (1.9% fractional BW) Return Loss = 20 db (equiripple) 2 symmetrical TZs Mobile satellite communication 4 th order filter with design parameters: Q ext0 = Q ext5 = K 12 = K 34 = S Q ext0 1 K 14 4 Q ext5 L K 23 = K 14 = K 12 K K 23

5 TM 01 Mode Resonator H-fields Cross-sectional view 0.225λ Tuning screw 0.13λ E-fields Dielectric Metallization Resonator geometry based on publication: Xi Wang; Ke-Li Wu, "A TM01 Mode Monoblock Dielectric Filter," IEEE Transactions on Microwave Theory and Techniques, vol.62, no.2, pp.275,281, Feb

6 Coupling Mechanisms External coupling (Q ext ) Probe coupling (K E ) Iris coupling (K M )

7 Filter Implementation Tuning parameters Screw insertion height f 0 Iris width K M Probe insertion height K E Coax pin height Q ext

8 Filter Tuning step 1 Tune height of screws so that f GHz Ensures a good starting point for optimization Produces a definite range for the mesh adaptation Filter response Single resonator Δ = 60 MHz Δ = 60 MHz

9 S2,1 / db S1,1 / db Filter Tuning step 2 Optimize response with TRF Strategy Lossless materials to reduce runtime Mesh adaptation with in-band samples New moving mesh feature New in 2016!

10 S1,1 / db Optimization using Move Mesh Move Mesh feature reuses the mesh throughout entire optimization Faster optimization! No mesh noise!

11 Multiphysics Simulation Why Multiphysics simulations? To analyse performance of real-world operation (incl. thermal & mechanical effects) To assist in a more robust design of the device (e.g. with thermal compensation)

12 Multiphysics Simulation Two typical scenarios: 1. High ambient temperature 2. High input power Use SAM workflow for integrated Solver Technologies

13 MPhysics Workflow #1 + Thermal distribution Specification: Ambient temperature of 60ºC Filter response Structural deformation

14 Thermal Distribution Constant ambient temperature of 60ºC

15 Structural Deformation Set zero displacement at coax ports Note the displacement of probe

16 S-Parameter Results Insertion Losses

17 Material Properties Remember we are working in 3 different computational domains!

18 Material Properties Reduce computational effort by simplifying the model for each simulation stage E.g. the coax probe is made of Brass with Goldplating. Therefore, for this model use: Brass in the Thermal and Mechanical simulations Gold in the EM simulations

19 MPhysics Workflow #2 Loss calculation + Thermal distribution Specification: 500W input power at 2.6GHz Filter response Structural deformation

20 Loss Calculation Surface and volumetric losses at 2.6 GHz

21 Thermal Distribution Thermal distribution as a result of dissipation losses

22 Structural Deformation

23 S-Parameter Results Insertion Losses

24 Conclusion Quick & efficient filter optimization High temperature & high input power effects All made possible by the integrated technology of CST STUDIO SUITE and there are even more MPhysics analyses possible!! (e.g. multipaction, corona)

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