一种新型宽带环形滤波器设计

本文设计了一种基于带有两个半波长短路调谐枝节的双模环形谐振器的新型宽带滤波器。该滤波器能够在通带两侧各产生一个传输零点,使得滤波器的插入损耗在通带外的衰减非常迅速,从而提高了滤波器的频率选择特性。利用＂奇、偶模理论＂对双模环形谐振器进行了分析,并给出了传输零点的计算公式。结合传输零点公式和仿真软件设计出了一个中心频率为4.25GHz、3dB相对带宽为45%的宽带环形滤波器。仿真结果表明,该滤波器具有低插入损耗和良好的频率选择性等优点。

Design of Novel Broadband Filter Using Ring Resonater

A novel broadband filter is presented in this paper by using dual-mode ring resonators with two λ0/2（λ0 is the wavelength at the central frequency of the filter） short-circuited tuning stubs.Due to the transmission zeros in the stopbands of the filter produced by the dual-mode ring resonator,sharp attenuations of are obtained for the insertion loss out of the passband of the filter,which thereby improves the selectivity of the filter.According to the analysis of the dual-mode ring resonator by using even-and odd-mode method,the calculated formulae of the transmission zeros are proposed in order to facilitate the design of the filter.Based on the formulae and simulation software,a broadband filter is designed with central frequency of 4.25GHz and 3-dB bandwidth of 50%.Simulated results show that the filter has good characteristics such as low insertion loss and good selectivity.