可控Metamaterial与结构的电磁波吸收特性研究

Research of Electromagnetic Wave Absorbing Characteristic of Controllable Metamaterial and Structure

提出了一种可控超电磁材料Metamatrial与结构，研究了在4～10GHz范围内的电磁波传输系数与单站雷达散射截面（RCS）的电可控特性。对开口谐振环（Split ring resonators，SRRs）和带有p-i-n二极管的金属细线阵列，通过对间断处置有的5个p-i-n二极管施加电压来改变介质和整个结构的电参数的有效特性，从而实现电磁波的传输特性控制和此种材料与结构的电控制。应用金属波导理论、ANSOFT HFSS，高、低阻抗表面（HLIS）和辐射边界条件等模拟传输系数和单站雷达散射截面（RCS），得出整个超电磁Metamatrial材料与结构在谐振频带6．0GHz附近有好的近似导通与截止的控制特性；对于垂直入射的平面波，在不加铁氧体情况下RCS可减小-5dBm，传输系数约-30dB（5．4GHz附近）；添加铁氧体其谐振频率将朝低频发生位移，在谐振点附近传输特性表现为更差，而通、断可控特性表现为传输系数可调范围约-28dB，RCS可调范围约-10dBm。

This paper presents and studies a kind of a controllable absorbing structure of metamaterial in which the transmission coefficient and radar cross-section （RCS） are electrically controlled（4 -10GHz）. For split ring resonators（SRRs）and metallic wire arrays with p-i-n diodes absorbing structure, wires are not continuous. Five p-i-n diodes are inserted in the wires, and they can be either in an on state or in an off state depending on the voltage to change effective properties of the medium and whole structure, and to realize the transmission control of electromagnetic wave and electronic control of such structure. Using the hollow metallic wave-guides theory, ANSOFT HFSS, and high-low impedance surface （HIS）, radiation boundary conditions and so on, the transmission coefficient and single radar cross section （RCS） are simulated. Whole absorbing structure of matematerial is with a resonance at a frequency around 6. 0GHz between about a reflective state and a transparent state. For vertical incident wave, such structure reduces RCS with the largest scope of -5dBm, and transmission coefficient is about -30dB（around 5.4GHz）with no ferrite. But, the resonance frequency moves towards lower frequency adding ferrite in medium, and controlling property is worse,controlling range is about -28dB for transmission coefficient, and single radar cross section （RCS） is about -10dBm.