General design of compact waveguide coupler with homogeneous media

Abstract

Based on finite embedded coordinate transformation method, a general transformation is given to design a compact waveguide coupler. It removes the limitation of material inhomogeneity and makes the coupler be more easily realized. It also offers us much freedom and flexibility in choosing the appropriate material parameters to practically implement the device. Full wave simulation based on the finite element method is performed to confirm the performance of the waveguide coupler.