四分之一模基片集成波导双频滤波器的设计

Design of dual-band filter based on quarter-mode substrate integrated waveguide

根据基片集成波导和矩形波导的等效关系,设计了一款四分之一模基片集成波导双频滤波器,首先分析了单个四分之一模基片集成波导(QMSIW)的谐振电场和传输特性,通过2个三角形QMSIW进行级联,增大滤波器带内回波损耗。腔体表面刻蚀CSRR结构,输入输出馈电处引入枝节,提高滤波器带外抑制性能,实现了QMSIW的双频滤波器。其中心频率为6.0和11.2 GHz,相对带宽为6%和4%,带内插入损耗小于1.9 dB,带内回波损耗大于9 dB,通带外的抑制大于20 dB。测试结果与仿真具有良好的一致性。该设计具有加工简单,低损耗等特点,可广泛用于射频电路中。

According to the equivalent relation between the substrate integrated waveguide and the traditional rectangular waveguide, a dual-band filter based on the quarter-mode substrate integrated waveguide(QMSIW) is proposed. First, the resonant electric field and transmission characteristics of QMSIW are analyzed. Two triangle QMSIW are cascaded to increase the in passband return loss. A pair of complementary split-ring resonator is etched on the surface of a resonator cavity, adding notching stubs to the input port, the suppression of signals stopband can be further enhanced. The central frequency of the filter is 6.0 and 11.2 GHz, fractional bandwidth is 6% and 4%, respectively, insertion loss in the passband is less than 1.9 dB, the return loss in the passband is greater than 9 dB, and the rejection outside the pass band is greater than 20 dB. The test results are in good agreement with the simulation results. The filter has some practical and application significance.