Low-RCS Metasurface Antenna Array Design With Improved Radiation Performance Using Odd- and Even-Mode Analysis

Abstract

In this letter, a novel design strategy for a linearly polarized metasurface antenna array that integrates low scattering and well-behaved radiation is proposed. First, a metasurface is designed with 180° reflection phase difference under orthogonal normal incident waves. By introducing L-feeding patches along the orthogonal direction to the metasurface, two antennas are constructed. Odd- and even-mode analysis is utilized to comprehensively analyze the working mechanism of the antennas and guide its radiation performance improvement. Then with the aid of coding and optimization, the two radiation elements are arranged to form a low-scattering metasurface antenna array. The measured impedance bandwidth for | <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</sub> | below −10 dB is 5.05–5.42 GHz, whereas the boresight gain varies from 11.7 to 13.7 dBi over the operating bandwidth. The measured monostatic radar cross section (RCS) of the proposed array is prominently reduced under the <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</i> -polarized incident wave, with a 6 dB reduction bandwidth of 30% (5.1–6.9 GHz).