一种利用环形双模谐振器实现的带阻滤波器

A Novel Bandstop Filter Using Square Ring Dual-Mode Resonator

提出了一种利用双模环形谐振器实现的带阻滤波器。该滤波器由一个对称的双模环形谐振器以及一段四分之一波长的平行耦合线组成。借助于在普通环形谐振器的两个相对边上添加一对小贴片,环形谐振器的两个简并谐振模式可以被可控的分离,从而可以构成带阻滤波器的工作频带。平行耦合线的作用是为了对双模谐振器进行馈电,同时也被用做两端口间的阻抗变换器。在理论分析之后,利用平面PCB工艺设计制作了滤波器样品,并对其进行了测量,进一步证明这种设计的有效性。

In this paper, a dual mode bandstop filter is presented, which consists of a symmetrical dual mode square ring resonator and a coupled transmission line with quarter-wave length. By adding two small patches in the opposite edges of the ring resonator, the mode perturbation can be realized, thus resonant frequencies of the degenerate modes can be separated to build the working stop band. Meanwhile, the quarter-wavelength line is used as the impedance inverter between the input and output, and the gap between the resonator and the inverter is used as the feeding structure. Filter samples are fabricated and measured and the experimental data validates this design well.