U-slot circular patch antennas with L-probe feeding

Abstract
Experimental results for U-slot circular patch antennas with L-probe feeding are presented. Using a foam layer of thickness ~0.1λ0 as a supported substrate, an impedance bandwidth of 38% (SWR ≤ 2) and a gain of 6.8 dBi have been achieved. The farfield radiation patterns are stable across the passband.