一种超薄吸波材料及其在缝隙天线中的应用

该文设计了一种超薄雷达吸波超材料，从等效电路和表面电流、电场分布分析了其吸波机理，并将其应用于波导缝隙天线的带内雷达散射截面(Radar Cross Section, RCS)减缩。该吸波材料仅由两层金属及中间的有耗介质板组成，厚度约为/175，最大吸波率达99.9%，且具有入射角和极化稳定吸波特性。将该吸波材料加载到波导缝隙天线上，实验结果表明：加载后的天线，回波损耗和增益几乎不变，在21~21角域，天线带内RCS减缩均在3 dB以上，法线方向RCS减缩最大超过17 dB。

An Ultra-thin Metamaterial Absorber and Its Application in Reducing RCS of Slot Antenna

An ultra-thin metamaterial absorber is designed and applied to reducing in-band Radar Cross Section (RCS) of waveguide slot antenna. The absorber is consisted solely of two metallic layers separated by a lossy dielectric spacer. In spite of its very thin structure, almost/175, the absorber achieves a maximum absorptivity of 99.9% and shows an excellent absorption stability performance with respect to different polarizations and incidence angles. By analyzing equivalent circuit and simulating the the electric field distribution, current distribution on patch and metallic ground plane at the resonance frequency, its physical mechanism of absorption of the electromagnetic wave is theoretically investigated. Experimental results show that the application of the absorber to waveguide slot antenna has hardly influence on antennas radiation performance, while the in-band RCS reduction of antenna is above 3 dB from21 to 21, and the most reduction value exceeds 17 dB at the boresight direction.