Mutual coupling reduction of microstrip antenna array using double negative substrate

In this paper, a double negative (DNG) structure is used as a substrate for a microstrip antenna array configuration. The design frequency lies within the frequency range in which the suppression of all kinds of surface waves is achieved. The mutual coupling, E- and H-planes, between adjacent patch antennas has been studied using the finite difference time domain (FDTD) method based on the piecewise linear recursive convolution (PLRC) algorithm and it is shown that the coupling due to the surface waves has been substantially reduced. The limiting effects of practically realizable DNG substrate on the bandwidth and the radiation pattern have also been investigated.