High-Gain Circularly Polarized Fabry–Pérot Patch Array Antenna With Wideband Low-Radar-Cross-Section Property

In this paper, we explore the adoption of a chessboard polarization conversion metasurface (CPCM) for constructing a low-radar-cross-section (RCS), high-gain circularly polarized patch array antenna. The proposed CPCM is used as the CPCMs’ chessboard configuration, which consists of adjacent two-layer substrates that have three metallic models. Low RCS is achieved by 180° (± 30°) reflection phase variations of two adjoining PCMSs. Gain enhancement is achieved by adopting a Fabry–Pérot cavity constituted by a PCM and the antenna’s ground. The antenna with a CPCM that operates at X-/Ku-band, excited by the feeding network that is rotated sequentially, is measured and fabricated. The patch array antenna impedance bandwidth based on the PCM was measured as 3.3 GHz (9.5–12.8 GHz) with a 3-dB axial ratio bandwidth of 11.6% and a high gain of 13.4 dBiC (9.5–12 GHz), more than 2.5 dB higher when compared with a patch antenna without a PCM. In addition, the patch array antenna produced a useful wideband RCS decrease in the operational bandwidth from 9 to 13 GHz.