高功率波段基于零折射率材料的波前相位改善

Wavefront phase improvement based on zero-refractive index metamaterials in high power band

零折射率材料作为超材料的一种在微波辐射中有广泛应用。为实现高性能的小型化天线,分析了零折射率材料的产生机理,设计了一种高功率金属网格材料天线透镜。数值模拟表明,零折射率材料透镜覆盖于一Ku波段喇叭天线口面时,可以改善喇叭天线波前相位,将喇叭天线的球面波前相位调制为较均匀的平面波,增益可提高2.27dB,喇叭天线的功率容量可达到610MW。研究了材料的层数n、层距h、周期a以及金属线半径r对S参数的影响,得到了所要求频率的最优材料结构。

Zero-index meta-materials have been investigated extensively for their unique electro-magnetic properties.In order to achieve the miniaturization of high performance antenna,a kind of zero-index material is designed,i.e.,metal-mesh structure,by adjusting the effective plasma frequency to the desired frequency band.The numerical simulations indicate that this metal-mesh structure can improve the wave-front phase and increase the gain when this structure is introduced to a horn antenna.The front wave phase of the antenna is changed from the spherical wave to the plane wave,the corresponding gain of the antenna is increased by at least 2 dB.The effect of the geometrical parameters,including the number of mesh layers n,the distance between adjacent layers h,the period a for a single mesh layer,and the radius of the metal lines r,are investigated systematically to optimize the directional emission.