同轴波导中二维金属光子晶体的电磁特性

Electromagnetic properties of two-dimensional metallic photonic crystals in coaxial transmission line

在同轴传输线内外筒之间引入金属支撑杆,建立了同轴传输线中二维金属光子晶体的物理模型。利用等效电路方法分析其传播情况,通过低频和高频近似得到了两个特征频率。其中,金属光子晶体的第一个带隙从零频开始,到第一特征频率截止;第一个通带从第一特征频率开始,到第二特征频率截止;第一、第二特征频率与金属光子晶体的等效电参数相关。利用CST软件对模型进行了仿真计算,验证了等效电路分析结果的合理性。仿真结果显示,在沿纵向具有N个周期的有限结构中,光子晶体通带分裂成(N-1)个传输峰。并根据其电场分布得到了色散曲线。

Periodically distributed metallic rods were introduced into the inner and outer conductors of the coaxial transmission line to form a two dimensional metallic photonic crystal structure.The circuit model of the metallic photonic crystal loaded transmission line was built up and the frequency characteristic of the model was studied.It is found that,the structure has two characteristic frequencies;the first band gap starts from the zero frequency and ends at the first characteristic frequency,and the first pass-band starts from the first characteristic frequency and ends at the second.A finite metallic rod array structure was simulated by the commercial software CST Microwave Studio.Because of the finite dimension of photonic crystals in the propagation direction,there exists a pass-band characterized by multi-peaked variations.The electromagnetic property of each propagation peak was analyzed,and its dispersion characteristics were studied.