提出了一种新颖的高选择性毫米波带通滤波器及其设计方法.在圆谐振腔的侧壁加入槽型微扰结构,通过调节微扰小槽的角度可以控制滤波器带外传输零点的位置,从而实现了带宽可调、高选择性的双模圆谐振腔带通滤波器.根据该滤波器结构、理论分析和仿真设计基础,研制了在V波段滤波器样品并进行了测试.实验结果与方正吻合得良好.与传统双模圆腔滤波器相比,所提出的滤波器不需要额外的调节结构,其设计方法简单,选择特性高,结构紧凑,具有一定的工程价值用于高性能平面化毫米波滤波器的设计.

A novel method for the realization of high selectivity millimeter wave band pass filters is presented. A small perturbing notch was etched at sidewall of a dual-mode circular cavity to improve cross coupling between two orthogonal modes. By properly changing the perturbing angle, the bandwidth is expanded and location of the transmission zero can be easily adjusted to significantly enhance the filter selectivity. The V-band filters have been designed, fabricated and measured. The experiment results showed an excellent agreement with simulation results. Unlike conventional filters, the proposed prototypes do not need any additional mechanical tuning element. It has merits of simple design process, high selectivity, compact size and quasi-planar structure.