Hybrid Finite Element Boundary Integral Method

By John Silvestro, ANSYS, Inc.

With recent improvements in the efficiency of integral equation solutions it is now possible to combine the integral equation procedure with the finite element method (FEM) in a hybrid Finite Element Boundary Integral approach (FEBI). In electromagnetics the FEM is a general purpose technique that solves for volumetric electric fields and can be used to accurately characterize microwave components, antennas and signal integrity issues. For antenna or scattering problems, the air region surrounding the model must be included and terminated with an absorbing boundary condition (ABC). The integral equation (IE) approach, which solves directly for currents on object surfaces is not as general as the FEM, but is often more efficient for large open problems since it does not require the surrounding air volume. By combining the two approaches in a FEBI technique HFSS users can accurately and efficiently simulate very complex, large open problems. This new technique will be available in the 13.0 release of HFSS™.

This paper will discuss the application and advantages of FEBI for solving antenna and scattering problems. A set of benchmarks that demonstrate the accuracy and efficiency of this newly implemented procedure will be presented. Finally 2 examples that use the domain decomposition method (DMM) together with the FEBI will be discussed.