RCS Reduction of a UHF Blade Antenna Using Phase Gradient Metasurface

In this paper, a phase gradient metasurface (PGM) loaded UHF antenna with radar cross section (RCS) reduction characteristic is proposed. The PGM is placed on the top and bottom of the UHF planer monopole to manipulate the reflected wave from the broadside direction to the offset direction. In order to realize RCS reduction with the different reflected directions and magnitudes, several different arrangements of the PGM are designed and discussed, and the simulated results proved that the different PGM arrangement methods can realize the different RCS distribution with few influences on the radiation performance of the UHF monopole antenna. The beam steered range of the reflected wave is ± 40 deg in xoz-plane and ±79 deg in yoz-plane. The RCS can be reduced more than 8 dB in X-band with the maximum reduction of 18.95 dB at 8.1 GHz for the normal incident direction. The -10 dB impedance of the UHF antenna is from 500 MHz to 3000 MHz, and the antenna can realize a quasi-omnidirectional radiation pattern within the frequency band of 600 MHz to 1600 MHz. The RCS reduction characteristic makes the proposed antenna a good candidate for airborne communication systems.