基于CQ拓扑的三通带滤波器的设计

提出和设计了一个三通带带通滤波器,采用CQ拓扑和缺陷地结构,产生了8个传输零点,获得了高频率选择和带间隔离。半波长阶梯阻抗谐振器(SIR)设计为同时谐振在第1、2和3通带的公共谐振器,公共谐振器和分别谐振在第1、3通带的1/4波长谐振器(QWR)组合构成CQ拓扑结构。同时,阴刻在地表面的缺陷地结构提高了调节耦合系数的自由度,便于调节耦合系数来满足特定要求。设计、加工和测量了工作在2.4GHz、3.4GHz和5.5GHz的三通带滤波器,测试结果和仿真结果的一致性证明了提出的设计方法的可靠性。

Design of Tri Band Filter Based on CQ Topology

A tri band band pass filter is proposed and designed in this paper. By employing CQ topology and the defected ground structure (DGS), eight transmission zeros (TZs) are generated and high frequency selectivity and inter band isolation are obtained. The two section half wavelength stepped impendence resonators (SIRs) are carefully designed as common resonators which resonate at the first three passband simultaneously, the quarter wavelength resonators (QWRs) that resonate at the first and third passband respectively are added to assemble quadruplet filters. Meanwhile, the defected ground structure (DGS) is etched on ground surface to adjust the coupling coefficients flexibly for specified demands. The tri band band pass filter operating at 2.4, 3.4, and 5.5 GHz simultaneously is designed, fabricated and measured. The good agreement between measured and simulated results verifies the the reliability of the proposed design method.