Abstract

A system-level cross-domain electromagnetic (EM) design and analysis simulation flow is presented whereby the Finite-Element-Method (FEM) and Finite-Difference-Time-Domain (FDTD) methodologies integrate to deliver greater design insight and efficiency. For example, a complex structure such as an antenna, a printed circuit board or an IC package is first characterized for its near field EM properties using FEM. Then, the results of which are converted to a time domain planar excitation signals by using Inverse-Fast-Fourier-Transform (IFFT) and integrated by way of electromagnetic equivalent theory into an FDTD simulation of the system for the purpose of delivering the user greater design insight and efficiency. In particular, the FEM results map over into a FDTD simulation as a surface source module that also allows for the inclusion of other/additional large-scale (as defined by its multiple of wavelengths) objects. This cross-domain integrated field solver workflow combines the advantages of both FEM and FDTD methods. It keeps the accuracy and flexibility of FEM to model complex structures while at the same time, employs the memory and computation efficiency of FDTD method to fulfill the large-scale system-level simulation. An integrated environment combining the two solver methodologies seamlessly enables cross-domain usability, capacity, and accuracy. Furthermore, the common environment empowers users with component extraction accuracy of FEM and test-measurement accuracy of FDTD typically required for system-level electromagnetic interferences/compatibility (EMI/EMC) and radiation compliance analysis. To verify the capability of the FEM to FDTD flow, a dipole and patch antenna in free space are simulated and compared with the FEM method. The simulation results show that the presented FEM to FDTD flow could keep the far field frequency domain accuracy very well. Compared with the pure FEM or FDTD simulation, this flow allows user to solve a very large-scale model interacting with models carrying fine details in small parts more efficiently. An antenna mounted on a car simulation is also presented to show the versatility of this integrated field solver.