基于复合左右手传输线的超窄带基片集成波导有耗滤波器

Ultra Narrowband Substrate Integrated Waveguide Lossy Filter Based on CRLH Transmission Lines

基于四分之一模基片集成波导结构,提出了一款小型化的超窄带有耗滤波器。通过在谐振器内部添加复合左右手传输线以及电阻耦合,不但使整个电路结构变得更加紧凑,还实现了通带内的平坦化以及阻带性能的提升。使用本振模仿真的方法得到了对应谐振器的大小,并将两个腔体进行级联,然后再加入电阻耦合以及左右手传输线,设计出一款超窄带的小型化基片集成波导有耗滤波器。仿真结果显示:滤波器的工作频率为3.65 GHz,带宽为200 MHz,相对带宽为5.4%,带内插损为1 dB,回波损耗优于28 dB。相较于传统滤波器设计,该结构实现了小型化、超窄带以及更高的回波损耗。为了验证设计结构的准确性,进行了实物加工测试,仿真与实测结果吻合良好。

Based on the quarter mode substrate integrated waveguide structure,a miniaturized ultra narrow band loss filter is proposed in this paper.By adding a composite left-and right-handed transmission line and a resistive coupling inside the resonator,it not only has the compact structure,but also achieves the flat passband and improves stopband performance.Based on the eigen-mode simulation method,the cavity size of the corresponding resonator was obtained and the two cavities were cascaded.Then,resistance coupling and left-and-right-hand transmission line are added to design the ultra-narrow band miniaturized substrate integrated waveguide lossy filter.The simulation results show that the bandwidth of the filter operating at 3.65 GHz is 200 MHz with the relative bandwidth of 5.4%.Simultaneously,the insertion loss and return loss are 1 dB,28 dB,respectively.Compared to traditional filter design,this structure achieves miniaturization,ultra narrowband and better return loss.