Research On Green's Function Calculation For Electromagnetic Simulation Of Layered Medium Structures

With the improvement of modern computer science and technology,and the development of wireless communication technology in the direction of high frequency,the design of electronic communication systems is getting smaller and smaller,more and more sophisticated,and its working environment is becoming more and more complex.Therefore,the electromagnetic characteristics of the target are analyzed.It has become a research hotspot in the field of electromagnetics.Compared with the method of experimental measurement,the technology of using numerical simulation has the advantages of high efficiency and low cost.Nowadays,various theories of computational electromagnetics have been widely used in various electromagnetic problems,and many researches have also been done on the application of electromagnetic numerical simulation technology,but there are still challenges in the face of complex electromagnetic simulation problems with multi-layered media.The radio frequency integrated circuit is a planar metal dielectric stack structure,and the effect of the dielectric can be included by using the planar layered Green's function,so the dielectric layer does not need to be meshed,thereby reducing the amount of calculation.The work of this paper is mainly to study the planar multilayer Green's function of radio frequency integrated circuits and propose a new hybrid fast Hankel transform(FHT)method.First of all,because traditional FHT calculates the space domain Green's function of planar multilayer media,it is difficult to obtain accurate numerical calculation results because of the branch cutting singularities and surface wave poles on the integration path,although the Hankel transform can be changed from the complex The real axis on the plane is transformed to the integration path of the first quadrant,which can obviously avoid the singularity,but the parameter of the integration kernel has become a complex number,so the FHT algorithm cannot be used directly to solve it.In this paper,some improvements are made to the traditional FHT algorithm,the Bessel function with a complex argument as a sum of terms of product of Bessel function with the real part of the argument and Bessel function with the imaginary part of the argument,which overcome the calculation inaccuracy caused by the singularity.It overcomes the problem that the traditional FHT method cannot handle semi-open and open multi-layer media,and at the same time overcomes the calculation inaccuracy caused by singularities.Then,on the basis of the improved FHT method,the steepest descent path(SDP)algorithm and the Lagrangian interpolation technique are combined.Using this method greatly reduces the electromagnetic simulation time of the planar layered medium.And it has accurate numerical calculation results for the design of large-scale circuits and the electromagnetic simulation of highly-designed chips.For general multi-layer media problems,compared with the traditional SDP method,the hybrid FHT reduces the computing time by more than 48% while consuming similar computer memory resources,the method proposed in this paper expands the applicability of the traditional FHT method and improves the efficiency of Green's function calculation,especially in complex multi-layer media problems.Finally,in order to verify the effectiveness of the proposed method,the proposed method is applied to integrated circuit simulation,and the calculation results are compared with the experimental test results and commercial software results,which proves the accuracy of the proposed method.