Wideband Low RCS and High Gain Circularly Polarized Fabry-Perot Antenna Array

A new Fabry-Perot (F-P) cavity antenna array with wide circularly polarized (CP) operating bandwidth using checkerboard polarization conversion metasurface (CPCM) superstrate is proposed for wideband CP radiation, high realized gain, and low radar cross section (RCS) applications. The bottom part of the CPCM performs as a superstrate for the F-P resonant antenna. A positive phase gradient of the CPCM unit cell generates wideband enhancement gain. Simulated results illuminate that the array has a wideband of S
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<-10 dB in the range of 10.86-14.18GHz and a wideband of axial ratio (AR) < 3dB in the range of 10.97-13.60GHz. The peak realized gain is enhanced by around 3 dB, and the 3-dB realized gain bandwidth is achieved from 11.07 to 13.20GHz. Morever, the array has a wide over 10-dB RCS reduction bandwidth in the range of 10.00-19.30GHz compared to the reference array without CPCM. The proposed array has the advantages of wideband, circular polarization, high gain, and low RCS, which can be used for stealth platforms.