基于非谐振节点的基片集成波导滤波器设计

Design of substrate integrated waveguide filter with nonresonating node

针对微波滤波器小型化和高性能的应用要求,基于非谐振节点技术,提出了一种高选择性的双模基片集成波导带通滤波器.非谐振节点通过带线谐振器实现,可以在源负载之间引入额外的信号传输路径,与传统的双模基片集成波导滤波器相比,该滤波器可以引入额外的传输零点,从而提高滤波器的选择性和带外抑制.此外,带线谐振器嵌入基片集成波导谐振腔的内部,不占据额外的电路面积,使其结构更加紧凑.最后,设计并加工了一款工作频率为28GHz,相对带宽为1.6%的高选择性带通滤波器.测试结果与仿真结果相一致,表明了所提出设计方法的可行性.

A novel dual mode substrate integrated waveguide (SIW) filter with non-resonating node (NRN) was proposed to ensure miniaturization and high selectivity. The NRN was implemented by strip - line resonator, which introduces extra signal transmission path between source and load. As a result, an additional zero transmission can be introduced compared with conventional dual mode substrate integrated waveguide filters. In addition, the proposed filter can achieve a compact circuit size since the strip-line resonator is embedded in the SIW cavity without extra layout. To verify the feasibility, the proposed filter with fractional bandwidth of 1. 6% at 28 GHz was fabricated and characterized. The experimental results were consistent with the simulation, which proves the reliability of the design.