谐振加载耦合微带线传输特性分析及其应用研究

Transmission Characteristics Research and Application of Parallel Coupled-Line Loaded Open-Circuited Resonator

对一种具有多传输零点特性的新型带阻结构-谐振加载耦合微带线的传输特性进行了系统研究。在建立奇偶模等效电路模型的基础上,首先分析在无限长周期条件下该结构基本的通带-阻带响应;然后考察不同端口阻抗和负载对使用单个单元的滤波器通带和阻带频响特性的影响。并据此提出了一种具有插入损耗低,时域特性平坦特点的宽阻带低通滤波器设计方法。由于该设计方法完全采用闭式解析公式计算,故具有快速有效的优点。最后,采用上述方法设计研制了一个截止频率为2.4GHz的低通滤波器。其通带内插损小于0.1dB,衰减大于20dB的阻带宽度大于7.2GHz(3.6GHz^10.8GHz)。

A novel compact one-section bandstop structure with three controllable finite transmission zeros is researched, which consists of a pair of symmetrical parallel coupled-lines and single open-circuited resonator. Through the even- and odd-mode analysis method, its basic pass-stop characteristics in the case of infinite period array are investigated firstly. And then, the effect of port impedance for single unit is calculated. With this configuration, a new type of low-pass filters （LPFs） with low insert-loss and smooth delay characteristic in pass band is designed. Since the design expressions are all analytical, the design process in this paper is fast and accurate. Finally, a low-pass filter which has a cutoff frequency at 2.4GHz is developed. The insertion-loss in pass band is less than 0. 1dB, and the rejection band is over 20dB from 3.6GHz to 10.8GHz .