梳状SIR交叉耦合同轴腔滤波器的设计

Design of combline SIR cross-coupled coaxial-cavity filter

四分之一波长SIR(Stepped Impedance Resonators)作为同轴腔滤波器的基本谐振单元,利用梯度法优化提取了交叉耦合滤波器的耦合矩阵,采用梳状线形式,设计了一种梳状SIR交叉耦合同轴腔滤波器。从滤波器的实测曲线可以看出,这种形式的滤波器很好的实现了宽阻带、小体积和高选择性的设计思想。

λg/4-type SIR is taken as basic resonator unit of coaxial filters. Coupling matrix of cross-coupled filter is extracted by the optimization method of analytic gradients. Adopted pectination form, a kind of combline cross-coupled coaxial-cavity filter with λg/4-type SIR is designed in this paper. The measured results show that fabricated four-cavities filter attains the demanding goals of small size, wide stopband and high selectivity.