Wideband RCS Reduction of Microstrip Antenna Array Using Coding Metasurface With LowQResonators and Fast Optimization Method

In this letter, a novel coding metasurface (CM) based on low Q resonators and fast optimization method is proposed to achieve wideband radar cross section (RCS) reduction of the microstrip antenna array (MAA) while maintaining its radiation properties. Theoretical analysis reveals the relationship between the Q value and the phase shift of the resonator, which indicates that the wideband control of the reflected wave can be achieved with the low Q resonator. Moreover, the fast optimization method based on the convolution theorem is proposed, which enhances the optimization efficiency of the coding matrix. Finally, the CM with two kinds of low Q resonators is constructed and applied to the MAA for wideband RCS reduction. The measured results indicate that the proposed low RCS MAA (LRMAA) can realize more than 10 dB RCS reduction in 5.8–21.5 GHz, which also demonstrates superior specular scattering suppression. In parallel, the radiation properties of the LRMAA are consistent with those of MAA. The proposed strategy achieves the high integration of radiation and scattering properties, which has potential applications in antenna systems of stealth platforms.