新型高抑制波导滤波器设计

Design of a novel high suppression waveguide filter

提出了一种新颖的波导带通滤波器设计。该滤波器是一个四阶广义切比雪夫滤波器,中心频率为9.93GHz,带宽为200 MHz,插损小于0.5 dB,带内回波损耗大于20 dB。谐振器为CQ结构,通过一个矩形波导膜片(一个不完全高度的导电杆),实现了交叉耦合,相比传统方法,产生一个额外的传输零点。由于在高端产生了两个零点,使得滤波器在阻带高端10.1 GHz处的带外抑制达到了35 dB以上。仿真实验证明了该设计方法能显著提高滤波器的带外抑制,对滤波器的小型化、高性能化有一定的意义。

A design of a novel waveguide bandpass filter was proposed. The filter was a four-order generalized Chebyshev filter with centre frequency of 9.93 GHz, bandwidth of 200 MHz, insert loss of under 0.5 dB, return loss of above 20 dB in the pass band. CQ topology was used and cross coupling was realized via a rectangular waveguide iris with an incomplete height conducting post. Resonators were arranged in a quadruplet configuration and employed a cross coupling to produce an extra zero in comparison to classical approaches, there were two zeros at the high-end, thus the filter＇s suppression at 10.1 GHz reached above 35 dB. Simulating experiments show that the design can highly improve the suppression in the band wide. It＇s meaningful for compact and excellent filters.