Wideband RCS Reduction of Fabry-Perot Resonator Antenna Based on Diffuse Scattering Method

Abstract

Three methods to reduce the RCS of Fabry-Perot (FP) resonator antenna using diffuse scattering are verified and compared in this paper. They are 1 bit random coding, 2 bit random coding, and 2 bit random phase gradient coding method. In order to realize reflection phase coding, a receiver-transmitter type unit with adjustable reflection phase from top side is proposed. Metasurface (MS) composed of this unit is the best choice to achieve the RCS reduction of FP resonator antenna, because it has the ability to independently control the reflection phase on both sides. By changing the size of radiation patch, two units with 90 • reflection phase difference and four units with 90 • reflection phase difference from top side can be obtained. They are used to compose MSs with different reflection phase distributions. These MSs can form FP resonator antennas with RCS reduction characteristics. Subsequently, three antennas are fabricated and tested, and the test results are compared. The results show that the FP resonator antenna using 2-bit random phase gradient coding has the best performance. It achieves the wideband RCS reduction of antenna and has the least influence on radiation performance. The proposed antenna A3 achieves an average RCS reduction of 12 dB over the bandwidth range of 7.7-13.7 GHz while maintaining a peak gain of 18 dB and good radiation patterns.