Theory And Technology Of Electric-thermal Modeling Of Microwave Circuit Based On FDTD

Due to the increasing integration density and interconnect complexity,the thermal effects of microwave circuits can not be ignored,especially when the circuits are operating in high power or high temperature environments.Therefore,the electro-thermal coupling analysis of the microwave circuits is necessary.Many numerical methods are used to calculate multiphysics.The Finite-Difference Time-Domain(FDTD)method is an ideal choice for electro-thermal coupling simulation,because it can effectively simulate the transient response of electromagnetic fields and thermal fields,and the geometry of the structure and the substrate material in FDTD can be very flexible.The current high level of integration of microwave circuits has facilitated the development of various complex multi-scale and multi-physics algorithms.In the simulation and numerical modeling of microwave circuits,the demand for computational accuracy,efficiency,dependence and universality continues to grow.Improving the precision and accuracy of numerical calculations for rigorous field simulation model and model design is particularly important.The application of numerical calibration technology can effectively eliminate the problem of port discontinuity caused by the lumped current or voltage excitation source in the numerical algorithm and improve the accuracy of microwave circuit parameter extraction.When combining the Open-Short circuit calibration(SOC)technique with the FDTD method to extract circuit parameters,we can greatly improve the simulation accuracy,develop the correct circuit model and obtain higher computational efficiency.Based on the FDTD algorithm,the electrothermal coupling analysis and numerical calibration technology are combined to extract the accurate transmission characteristic parameters of the microwave circuit considering the thermal effect,which makes a certain contribution to the extraction of accurate parameters of microwave circuits under multiphysical analysis.The main work content of this paper and the corresponding innovation contributions include the following two parts:Firstly,based on the theory of full-wave electromagnetic analysis and transient thermal analysis with FDTD,a reasonable numerical simulation process is given,the numerical model of the electro-thermal coupling analysis of microwave circuit structure is established and successfully applied to the electrothermal coupling analysis of the SIW structure and HMSIW structure.Secondly,the SOC calibration theory based on FDTD is introduced into the electrothermal coupling numerical model.The method of using SOC technology to carry out parameters on the core circuit of microwave electric heating coupling model is given.And the variation of the complex propagation constant of the DUT part of the SIW structure and HMSIW structure under different conditions is successfully extracted by this method.