Ka波段平板光子晶体波导传输特性测量

为了测量在Ka波段下空气孔型平板光子晶体波导的传输特性,提出采用从金属矩形波导将电磁波耦合进光子晶体波导并测量其传输特性的测试方案。根据两种波导传输模式的场分布,用两段介质尖劈作为电磁波从矩形波导到三角形晶格平板光子晶体波导的模式转换结构,该结构使用电磁场仿真软件找出最优结构尺寸。实验使用聚合物聚醚酰亚胺（PEI）作为介质材料,加工出实际结构,采用AV3629网络适量分析仪测试整个系统的S参数;结果在27~40 GHz之间的传输系数为？7 dB左右,将测试数据与数值结果相比较,并重新设置PEI材料的损耗参数进行仿真,最终,测试结果在损耗角正切为5×10？4的情况下与仿真数据相一致,表明本文提出的模式转换结构有效,平板型光子晶体结构在微波波段的应用打下基础。

Measurement of transmission characteristics of slab photonic crystal waveguide in Ka-band

In order to measure the transmission properties of the air hole type slab photonic crystal waveguide（PCW） in Ka band,the test solution,with which the electromagnetic wave is coupled from rectangular waveguide to PCW,is proposed.Two tapers are adopted as modes conversion structure between the metal waveguide and the PCW based on the two types of the field distribution of the two waveguides’ transmission modes.And the optimal taper structure size is car-ried out with the electromagnetic simulation software.The designed PCW and taper structures are made of the PEI,and the ＂S＂ parameter of the system is measured by the vector network analyzer AV3629.The result is that the transmission coefficient is about ？7 dB from 27 GHz to 40 GHz.With the comparison of the measurement data and the simulation re-sult,the transmission of the system with different loss parameters of the PEI is calculated again.At last,it is found that the measurement data is well accord with the simulation result with the loss tangent tanδ=5×10-4 of the PEI.It is indicated that the proposed structure is effective,which is the foundation for the application of PCW in microwave range.