A Dual Wideband Compact Shared-Aperture Microstrip Patch/Fabry–Perot Resonator Cavity Antenna

In this article, a dual wideband compact shared-aperture microstrip patch/Fabry–Perot resonator cavity antenna is proposed. A reflective meshed patch is designed to conduct as the shared surface, which works as the radiator at the lower band but the partial reflective sheet (PRS) at the upper band. A transmissive meshed patch is designed as the parasitic element to broaden the lower bandwidth without influence on the upper band radiation. The shaped ground is used to improve the front-to-back ratio at the lower band while maintaining a compact size. Moreover, the reflective meshed patch, which is built by two complementary frequency selective structures (FSSs), shows a positive reflection phase gradient to broaden the bandwidth of the antenna at the upper band without influence on the lower band radiation. The measurements reveal that a common bandwidth of ( $\vert \text{S}_{11(22)}\vert < -10$ dB, gain reduction < 3 dB) 25.4% and 21.3%, an isolation higher than 40 and 22 dB, a peak gain of 9.01 and 16.6 dBi at UHF band and C-band are achieved, respectively. The above properties make the proposed antenna suitable for dual-band point-to-point line-of-sight (LOS)/non-LOS (NLOS) communication systems.