A Low-RCS and High-Gain Circularly Polarized Antenna With a Low Profile

A low-radar-cross-section and high-gain broadband circularly polarized (CP) antenna with a low profile was specially designed using metasurface concepts. A polarization conversion metasurface is designed and used as the radiator of the proposed CP antenna. It is shown that a good axial ratio and high gain can be obtained over a broad band. Three kinds of artificial magnetic conductors are arranged around the polarization conversion metasurface. By making the discrepancies of the reflection phases among the artificial magnetic conductors and polarization conversion metasurface to be 90° in turn, the monostatic radar cross section of the proposed antenna is reduced in a wide frequency band covering the operation frequency band of the CP antenna. Good agreement between the experimental and simulation results is obtained.