Double-Tip Diffraction Modeling: 2-D Numerical Models versus High-Frequency Asymptotics

Abstract

The subject of single and double diffraction phenomena has long been investigated by high-frequency asymptotic techniques. However, integral or differential equation-based numerical methods suffer from computational complexity due to electrically large geometries encountered in high-frequency problems. The main purpose of this paper is to present the finite element (FEM) diffraction modeling of double-tip structure and to compare its results with high-frequency methods and other numerical models. FEM is made feasible for modeling of such an infinitely long structure by utilizing the locally conformal perfectly matched layer (PML) approach, which enables the use of finite-sized structure. MATLAB codes are developed and various numerical examples are demonstrated in a comparative manner.