Finite-element analysis of complex axisymmetric radiating structures

A finite-element method (FEM) is developed for the analysis of complex axis ymmetric radiating structures. The method is based on the electric field fo rmulation with the transverse field expanded in terms of edge-based vector basis functions and the azimuth component expanded using nodal-based scalar basis functions. This mixed representation of the electric field eliminate s spurious solutions and permits an easy treatment of boundary conditions o n conducting surfaces as well as across material interfaces. The FEM mesh i s truncated using a recently developed cylindrical perfectly matched layer (PML). The method has been successfully applied to three radiating structur es: a corrugated horn antenna, a spherical Luneburg lens, and a half Maxwel l fish eye. Numerical results are presented to show the validity, accuracy, and efficiency of the method.