基于E型双模谐振器的源负载耦合带通滤波器设计

摘要

为实现滤波器的小型化和高性能,提出了两款中心加载的E型双模谐振器,并对其进行了奇偶模分析。在此基础上通过引入源负载耦合,采用ADS与HFSS软件进行了仿真与优化。开路支节加载与短路支节加载的E型双模谐振器分别比方环谐振器减少42.8%与52.6%。实测结果表明,设计的滤波器中心频率分别为4.22 GHz和3.75 GHz,相对带宽分别为33.6%和9.1%,带内插损分别为-0.9 dB和-1.9 dB,带外零点位置与计算仿真结果吻合良好。这两款滤波器不仅尺寸小、插损低,并且具有宽阻带、传输零点可调的优点,短路支节加载的双模滤波器在选择性与带外抑制方面性能更好,可以广泛应用于各种微波电路中。%To realize compact and high performance filters,two novel centrally loaded E-shape dual-mode resonators are presented and analyzed. Simulation and optimization are made by use of ADS and HFSS. Compared with the square loop resonator, the size reduction of the proposed resonators are 42. 8% and 52. 6% respectively. Measured results show that the filters have the center frequency of 4. 22 GHz and 3. 75 GHz, the fractional bandwidth of 33. 6% and 9. 1%,the minimum insert loss in passband of -0. 9 dB and-1. 9 dB respectively. The measured positions of the transmission zeros agree well with the simulations. As The filters feature not only compact size, low insertion loss, but also wide stopband and controllable trans-mission zeros. Short stub loaded dual-mode filter has better performances in selectivity and out-of-band rejection and it will find wide application in microwave circuits.