A High-Gain Wideband Microstrip Patch Antenna With Folded Ground Walls

This letter proposes an approach to improve the gain of a microstrip patch antenna on a suspended substrate without compromising its bandwidth. The ground plane of the antenna is folded upward to form sidewalls parallel to the nonradiating edges. The distance from the patch edges and the height of the sidewalls are determined to maximize the radiation performance of the resultant antenna. This approach results in a peak gain better than 12 dBi and impedance bandwidth of around 45
$\%$
. Simulation studies indicate that sidewalls parallel to radiating edges degrade the antenna performance.