基于基片集成波导的双通带滤波器设计

Design of Double Passband Filter Based on Substrate Integrated Waveguide

为有效提高滤波器选择性和带外抑制水平,研究了一种在K波段工作的单腔双模基片集成波导带通滤波器。在此基础上,将这样的两个单个基片集成波导谐振腔进行非对称级联,通过经典的磁耦合,调整TE101模式和TE102模式的耦合系数以产生传输零点,从而实现双通带。实测结果表明,两个通带的中心频率在15.3 GHz和24.6GHz的相对带宽分别是4%和3.9%,两个通带的插入损耗均优于1.5 dB,回波损耗优于15 dB,且滤波器的尺寸仅为13.4 mm×22.4 mm。实物测试结果与仿真设计相吻合。

In order to effectively improve the filter selectivity and out-of-band rejection level,a single-cavity dual-channel substrate integrated waveguide bandpass filter operating in the K-band was investigated.Based on this filter,two single substrate integrated waveguide resonators were asymmetrically cascaded,and the coupling coefficient of TE101 mode and TE102 mode was adjusted by classical magnetic coupling to generate transmission zero point,thereby realizing the double pass bands.The measured results show that the fractional bandwidth of centerband frequencies of the two passbands are 4%and 3.9%at 15.3 GHz and 24.6 GHz,respectively.The insertion loss of both passbands is better than 1.5 dB,and the return loss is better than 15 dB and the filter size is only 13.4 mm×22.4 mm.The physical test results are consistent with the simulation design.