一种具有吸波和相位相消特性的共享孔径雷达吸波材料

A kind of shared aperture radar absorbing material with absorber and phase cancellation characteristics

提出了共享孔径雷达吸波材料(shared aperture radar absorbing material,SA-RAM)的设计方法.该方法将无源人工电磁媒质(metamaterials,MTM)的散射问题等效为有源阵列的辐射问题进行研究,利用阵列天线原理对有限周期MTM单元构成的MTM子孔径的位置信息、幅度信息、相位信息进行优化设计,实现具有不同功能的SA-RAM.在此基础上,设计了一种基于人工磁导体(artificial magnetic conductor,AMC)子孔径和完美吸波体(perfect metamaterial absorber,PMA)子孔径的SA-RAM,该SA-RAM通过将AMC子孔径与PMA子孔径交错布阵,实现了具有吸波和相位相消特性的SA-RAM.仿真和实验结果表明,该SA-RAM较金属板的后向雷达散射截面(radar cross section,RCS)在5.5—8.3 GHz都有明显的减缩,在5.54 GHz处的减缩是由于PMA的高吸波率引起的,在7.0 GHz处的减缩是由于AMC子孔径和PMA子孔径相位相消引起的.研究结果对频域和空域隐身相结合的雷达吸波材料设计具有重要的指导意义.

A method of designing a kind of shared aperture radar absorbing material （SA-RAM） is presented, in which method the scattering problem of passive metamaterial （MTM） is converted into the radiation problem of active array. Multifunctional SA-RAM is realized by optimizing the position, amplitude, and phase of the MTM subarray composed of finite MTM structures based on the array theory. An SA-RAM with absorber and phase cancellation characteristics is fulfilled by interleaving artificial magnetic conductor （AMC） subarray and perfect metamaterial absorber （PMA） subarray. Simulation and experimental results demonstrate that the backscattering radar cross section （RCS） of SA-RAM is smaller than that of the metal plate in a frequency range of 5.5-8.3 GHz. Especially, the RCS reduction is caused by high absorbance at 5.54 GHz and by phase cancellation between AMC subarray and PMA subarray at 7.0 GHz. The idea can help to design radar absorbing material, which combines frequency stealth with space stealth function.