A wideband high-gain Fabry–Perot resonator cavity antenna with low-RCS property using metasurface structures

A wideband high-gain microstrip patch/Fabry-Perot (FP) resonator cavity antenna with low radar cross section (RCS) is proposed, which consists of a microstrip patch, a ground plane, a double-layer partially reflective surface (PRS), a resonant complementary metasurface (RCM), and a checkerboard metasurface (CBM). A PRS is designed as circular patches and rectangular slot patches corresponding to the top and bottom, for achieving high-gain with wideband. RCM consists of three rectangular patch arrays of varied sizes for bandwidth enhancement and compensation using characteristic mode analysis (CMA). CBM adopts a fusion of two 4 × 4 metasurface modes to achieve low RCS. The three types of metasurfaces collaboratively enable frequency band resonance in the proposed antenna, resulting in enhanced gain, wide bandwidth, and reduced RCS. The measured results agree well with the simulated ones, showing that the antenna has an impedance bandwidth of 37.3%, a peak gain of 14.9 dBi at 7.0 GHz, and its cross-polarization greater than 20 dB. Monostatic RCS reduction of 10 dB is achieved across the frequency range from 5.0 GHz to 17.6 GHz (111.5%).