Analysis of wide-band aperture-coupled microstrip antenna array by CN-FDTD

The Finite Difference Time Domain (FDTD) method is widely used for radiation and scattering problems in electromagnetics due to its ability to model heterogeneous and complex geometries. And a single wideband simulation results can be provided. In this paper a three-dimensional implementation of the lumped-element by Crank-Nicolson finite-difference time-domain (CN-FDTD) algorithm has been presented to simulate a wide-band aperture-coupled microstrip antenna array with an “hour glass” shape aperture. The difference equations allow arbitrary lumped elements to be inserted into one FDTD cell, preserving the full explicit nature of the CN-FDTD scheme. As a validation of the results by the proposed method, the results by commercial software are also reported. Compared with the results of the two methods, the reasonably good agreement is found. Consequently, the accuracy of CN-FDTD application for antenna design with lumped elements in this paper is verified.