Efficient MoM simulation of 3D metallic antenna connected to finite ground plane

An efficient method is presented to simulate a 3D antenna connected to a finite ground plane itself lying on a layered medium. The spectral interactions between equivalent currents of the antenna and the finite ground plane are accelerated thanks to an asymptotic extraction of the integrated spectrum. The term accounting for the asymptotic part is obtained in free-space. Besides, efficient techniques for finite ground planes of canonical shapes cannot be considered in this case because the connection between the ground plane and the antenna is established with a fine mesh region which breaks the symmetries of the finite ground plane equivalent currents. Here a method to remedy this issue and which efficiently simulates defected rectangular ground planes is presented. The method is based on Toeplitz matrices and the defect is taken into account by exploiting a memory-efficient direct method.