The Study Of Microwave Circuit Transient Electromagnetic--Thermal Co--Simulation Method

With the development of electromagnetic field and microwave technology,the working fre-quency of various microwave and radio frequency circuits is getting higher and higher,which makes the feature size of the actually designed microwave and radio frequency circuits con-tinue to decrease and the integration complexity continues to increase.The ensuing power consumption and thermal problems have become one of the main problems of microwave ra-dio frequency circuits.The problem of thermal effects can no longer be ignored.Therefore,it is very important to use appropriate numerical calculation methods to study electromagnetic-thermal co-simulation.The purpose of this article is to study the electromagnetic-thermal co-simulation method.The main research contents and innovations of the paper include the following parts:Firstly,this paper uses the Discontinuous Galerkin Time Domain method for electromag-netic simulation.Starting from the Maxwell equation in the time domain,the Galerkin test is performed on the equation to obtain the discrete matrix equation in the time domain,and the matrix equation is solved to realize the electromagnetic simulation.In the existing electromagnetic-thermal co-simulation methods,the Finite Difference Time Domain method and the Finite Element Time Domain method are generally used for electromagnetic simu-lation.The Finite Difference Time Domain method uses an orthogonal grid discrete cal-culation domain,which is easy to introduce step errors and is not conducive to modeling of complex surface models? the Finite Element Time Domain method needs to solve large sparse matrix equations,and the resource consumption is extremely high when simulating large-scale electromagnetic problems.In this paper,the Discontinuous Galerkin Time Do-main method is used as the electromagnetic simulation algorithm in the electromagnetic-thermal co-simulation process.This method can not only achieve flexible modeling of com-plex geometric models,but also achieve element level domain decomposition.Each element solves the matrix equation independently,avoiding solving large-scale sparse matrix equa-tions,which can facilitate the analysis of large-scale electromagnetic problems and paral-lelization.Secondly,this paper uses the Finite Element Time Domain method for thermal simulation.Starting from the heat conduction equation,the temperature field is developed using the node basis function,and finally the discrete matrix equation in the time domain is obtained,and the matrix is solved to realize the thermal simulation.Since the temperature field is a scalar quantity,the number of unknowns generated when the temperature field is expanded using the node basis function is small,and the resulting matrix size is also small.The Finite Ele-ment Time Domain method is suitable for analyzing thermal problems.Finally,this paper studies transient electromagnetic-thermal co-simulation and parallel tech-nology.According to the electric field intensity distribution obtained in the electromag-netic simulation,the electromagnetic loss power is calculated,and as a heat source,the electromagnetic-thermal coupling is realized.This article uses MPI parallel technology to achieve parallel electromagnetic-thermal simulation,improve computational efficiency and realize large-scale simulation of electromagnetic-thermal coupling problems.