Dual-slot feeding technique for broadband Fabry–Perot cavity antennas

A dual-slot feeding technique is proposed for broadband multi-layer periodic Fabry-Perot cavity (FPC) antennas achieving enhanced directivity as well as broadband radiation and matching performance. To demonstrate the feeding technique, two FPC antennas are presented formed by two- and three-layer periodic partially reflective surfaces (PRSs) placed in front of a ground plane. Two optimised microstrip-fed rectangular slots of different lengths etched on the ground plane are used to feed the multi-layer cavity antennas and significantly enhance the antenna bandwidth as well as the directivity performance. Measurements of a fabricated three-layer PRS antenna prototype are presented exhibiting 19 dBi gain with 16% fractional bandwidth and validating the simulation results.