Effect of a finite ground plane on microstrip-fed cavity-backed slot antennas

This paper examines the effect of a finite ground plane on microstrip-fed cavity-backed slot antennas. The uniform geometrical theory of diffraction is employed for calculating the diffracted fields from the edges of a slot antenna´s finite ground plane. Measured and simulated results are presented to illustrate the edge effect of a finite ground plane on a slot antenna´s return loss and radiation pattern. It is demonstrated that the finite ground plane has a small effect on a slot antenna´s radiation performance, which suggests that slot antennas are a superior candidate for mobile terminals compared to microstrip patch antennas.