High Directivity Fabry-Perot Antenna With a Nonuniform Partially Reflective Surface and a Phase Correcting Structure

In this communication, a superstrate for the high radiation performance of a Fabry-Perot antenna (FPA) is proposed that consists of a nonuniform partially reflective surface (NPRS) and a phase correcting structure (PCS). The NPRS and the PCS function to uniformize the amplitude and phase distributions, successively, of the FPA's aperture field, thereby achieving a high directivity and a high aperture efficiency. Due to the independent amplitude and phase manipulations, the antenna design procedure is relatively rapid and effective. As a proof of concept, an FPA sample at an operating frequency of 5.8 GHz with a diameter of 200 mm is designed. The NPRS, comprising metallic square rings with dissimilar dimensions printed on a printed circuit board (PCB), is designed according to the leaky-wave method. A two-layer PCB structure is adopted as the PCS, which is designed by the transmission line model integrated with full-wave simulations. The FPA with the NPRS and the PCS is fabricated and measured for verification. The simulated and measured results are in good agreement. The directivity of the FPA with the proposed superstrate is 21.49 dB and the corresponding aperture efficiency is as high as 95.49% at 5.8 GHz.