阶梯阻抗谐振器在微波双通带滤波器设计中的应用

阶梯阻抗谐振器（Stepped Impedance Resonator）寄生响应的位置可以通过调整谐振器阻抗比来控制,该特性使SIR成为设计双通带滤波器的理想谐振器。设计耦合谐振器双通带滤波器需要对两组外部品质因数和耦合系数进行综合,为了减少谐振器的数量同时简化耦合系数的提取,本文采用特定耦合结构设计滤波器,并研究了影响SIR主响应和第一寄生响应处外部品质因数的因素,设计了中心频率是1.9GHz和3.2GHz,部分带宽是5%和7%的双通带滤波器。仿真结果验证了设计方法的可行性。

Application of SIR in Microwave Dual-passband Filter Design

The position of spurious response of SIR（Stepped Impedance Resonator） can be controled by adjusting the impedance ratio of the resonator,this feature makes it the ideal resonator in designing dual-passband filter.The designing of coupled resonator dual-passband filter needs to synthesize two sets of external quality factor and coupling coefficient,in order to decrease the amount of resonators and simplify the abstraction of coupling coefficient,this paper adopts a specified coupling structure,and studies the factors which have influences on the external quality factor of the main response and the first spurious response of SIR,a dual-passband filter is designed,of which the center frequencies are 1.9GHz and 3.2GHz and the fractional bandwidth are 5% and 7%.The simulated result verifies the feasibility of the design method.