宽带曲折线圆极化器的分析与设计

摘要

通过分析单层曲折线极化栅板结构,得到N层曲折线极化器等效电路.根据级联网络的传输矩阵,推导曲折线圆极化器对入射电场两极化分量的传输系数和反射系数的表达式,进而得到入射波通过多层曲折线圆极化器后的轴比.建立曲折线周期结构单元仿真模型,分析单元参数对传输系数幅度和相位差的影响,从而设计一种宽带多层曲折线圆极化器.实验结果表明,该圆极化器在2.5～6.2 GHz频带内轴比小于3 dB,带宽可达到1.5倍频程.%By analysing the structure of single meander-line polarization,the equivalent circuit of N layer meander-line polarizer is obtained.According to the transmission matrix of the cascade network,the expression of the transmission coefficient and the reflection coefficient of the polarized component of the incident electric field is deduced,and then the ratio of the incident wave through the multilayer meander line polarizer is obtained.A simulation model of meander line periodic structure is then established,and the influence of the element parameters on the amplitude and phase difference of the transmission coefficient is analyzed,and a broadband multilayer meander line circular polarizer is therefore designed.Experimental results show that the axial ratio of the circular polarizer in the 2.5～6.2 GHz band is less than 3 dB,and the bandwidth can reach 1.5 octaves.