太赫兹波段复合十字孔型超介质滤波器的分析与设计

Analysis and design of composite cross-loop slot metamaterial filter in THz wave domain

利用谱域法对十字孔型超介质单元的滤波特性进行了理论分析,设计了工作在太赫兹大气通信窗口、中心频率为0.338 THz的十字孔型阵列超介质滤波器,其归一化透射率高达0.998。讨论了其结构参数对滤波特性的影响。分别利用相同十字孔、十字形、方形环结构对其滤波特性进行改进,对改进结果进行了对比。最终选用方形环与十字孔结合的复合阵列结构替换了十字孔型阵列结构,构成了复合结构的超介质滤波器。结果表明,其3 dB带宽为20.38 GHz,带外归一化透射率小于0.1,带外抑制更加良好,边带更加陡峭。

The cross-loop slot metamaterial unit was theoretically analyzed by using spectral domain method. The cross-loop slot array metamaterial filter was designed, which showed bandpass characters in the terahertz communication window and the center frequency was 0.338 THz and the normalized transmission rate reached 0.998, the relationship between structural parameters and filter properties was discussed. The identical cross-loop slot, cross-loop and square ring were used to improve the filter properties, and the results were compared. Eventually the cross-loop slot array structure was replaced by the composite cross-loop slot array structure, which consisted of cross-loop slots and square rings. Results show that the 3 dB bandwidth of the composite array structure metamaterial filter reaches 20.38 GHz, and out-of-band normalized transmission rate is below 0. 1. It has better out-of-band rejection and steepness ofsklrts.