The effects of a finite ground plane on the characteristics of printed patch antennas with and without a suspended patch

In most analyses of microstrip patch antennas the effects of a finite ground plane are neglected because it is assumed infinite. However, in mobile communication systems the ground plane of antennas must be finite. Therefore, the effect of the finite ground plane on the characteristics of printed patch antenna elements is worth investigation. In this paper a stacked patch antenna has been proposed and the effects of a finite ground plane on the total radiation pattern are investigated. In fact, we have shown that a truncated ground plane of width approximately one wavelength will produce a 3dB beam width for the patch of approximately 65 degrees in contrast to the 90 degrees which occurs for an infinite ground plane. A physical description of the reason for this is included.