A High-Gain Filtering Fabry-Perot Antenna With RCS Reduction

A high-gain filtering Fabry-Perot antenna (FPA) with radar cross Section (RCS) reduction is proposed. The design utilizes a partially reflecting surface (PRS) which is integrated with a chessboard arranged metasurface (CAMS) in a single-layered substrate. The CAMS is composed of periodic strip arrays to reduce monostatic RCS based on the phase cancellation principle. The PRS structure is a cross-slot array which is designed to work with both orthogonal orientations of the CAMS elements while yielding a high reflection magnitude. Accordingly, the proposed FPA achieves a high-gain broadside radiation and wideband RCS reduction. The filtering functionality is achieved from a T-shaped feed patch, which is, interestingly, enhanced by the integration of CAMS in the PRS. For validation, a prototype operating at 6.0 GHz has been fabricated and measured. The antenna with an overall size of $3.2\lambda _{{0}} \times 3.2\lambda _{{0}} \times 0.57\lambda _{{0}}$ at 6.0 GHz exhibits an impedance matching bandwidth (BW) of 5.73 – 6.23 GHz, a 3-dB gain BW of 5.76 – 6.17 GHz with the peak gain of 14.63 dBi, and an out-of-band suppression of ≥20 dB. Meanwhile, it achieves an RCS-reduction bandwidth of about 4.0 to 9.0 GHz (76.9%).