一种新型带宽可调微波滤波器的研究

Research on novel microwave filter with adjustable bandwidth

文中介绍一种人工表面等离激元型微波滤波器。该滤波器采用对称的三段式结构:第一段为槽线波导段,实现微波信号的输入/输出;第二段为过渡段,该段采用渐变阻抗技术,以电磁阻抗的良好匹配实现与第三段的良好衔接;第三段为周期性对称排列的具有椭圆弧面的凸形槽组成的SSPPs段。试验结果表明,这种结构的微波滤波器具有很好的滤波特性和良好的抗干扰能力。通过调节滤波器椭圆弧的滤波凸槽的几何尺寸,可以调控微波滤波器下阻带的截止频率和电磁场分布,以及电磁波的束缚效果。对比分析得出,该滤波器中的过渡段能有效改善微波滤波器的传输及反射特性,同时也可以增强高密度微波集成电路工作时的稳定性,因而能更好地应用于L~S波段的民用微波通信系统中。

An spoof surface plasmon plaritons(SSPPs)microwave filter is introduced in this paper,which adopts a symmetrical three-stage structure.The first section is the slot line waveguide section,which can be used to realize the input/output of microwave signal.The second section is the transition section,in which gradient impedance technology is adopted to achieve good connection with the third section by good matching of electromagnetic impedance.The third section is a SSPPs section consisting of a convex groove structure with an elliptical arc surface arranged in a periodic and symmetrical manner.The experimental analysis results show that microwave filter with this structure has good filtering characteristics and good anti-interference ability.By adjusting the geometric size of the filtering convex groove of the elliptical arc of the filter,the cut-off frequency and electromagnetic field distribution of the lower stop band of the microwave filter,as well as the binding effect of electromagnetic waves,can be controlled.The comparative analysis result shows that the transition section in the filter can effectively improve the transmission and reflection characteristics of the microwave filter,and can also enhance the stability of the high-density microwave integrated circuit while the filter is working,so it can be better applied to the civil microwave communication system in L~S band.