基于非谐振节点的SIW滤波器设计

Design of SIW Filter Based on Non-resonant Node

采用基片集成波导(Substrate Integrated Waveguide,SIW)设计了一种含有非谐振节点(Non-Resonant,NRN)的二阶单腔带通滤波器。TE101模式工作在非谐振状态下,此谐振模式分别和源/负载产生耦合,因而可以引入最大数量的传输零点,有效提高频率选择性。由于基片集成波导结构的限制,不利于滤波器设计的小型化,但是采用单腔多模技术在一定程度上减小了滤波器的体积。滤波器的中心频率为14.95GHz,带宽为0.98GHz,插入损耗为0.9dB,回波损耗大于20dB,测试结果与仿真结果吻合较好。

A second-order single-cavity substrate integrated waveguide bandpass filter with nonresonating node(NRN)is presented in this paper.TE101 mode works in nonresonating state,and it is coupled to the source/load respectively,hence leading to maximum number of transmission zeros which effectively improves the frequency selectivity in the stopband.Because of the limitation of the substrate integrated waveguide structure,it is difficult to minimize the filter.But single cavity multimode technology reduces the filter size to some extent.The minimum in-band insertion loss is about 0.88 dB,while the return loss is better than 20 dB centered at 15.05 GHz with bandwidth of 0.87 GHz.