Electromagnetic–Thermal Coupling Characterization of Temperature and Average Power Handling Capability of Integrated Passive Devices (IPDs) for High-Power Applications

This paper presents a high-fidelity electromagnetic-thermal coupled method for characterizing temperature rise and average power handling capacity of integrated passive devices used in RF front-end in various radar and communication systems. The proposed method employs a self-developed finite element method solver capable of incorporating temperature-dependent material parameters, with nonlinear and strong coupling between electromagnetic and heat conduction processes introduced. Efficient iterative algorithms and tailored preconditioners are implemented for supporting the solution of multiscale coupled problems. The method is validated against the commercial software COMSOL and HFSS through two benchmark cases: a thin-film microstrip interconnect and an output matching network. Further simulations are conducted on two representative integrated passive device structures—an input matching network and an inter-stage matching network often used in low noise amplifier and power amplifier—under varying power, frequency, and thermal boundary conditions. Numerical results are presented to demonstrate the maximum temperature rise and average power handling capacity of the structures, providing important some physical insights for the robust electromagnetic protection design of integrated passive device operating in an extreme or intentional electromagnetic interference environment.