基于圆头谐振器的低插损带通滤波器设计  

Design of a Low Insertion Loss Bandpass Filter Based on Round Head Resonator

作　　者：张友俊[1] 朱祥李 宋婉萍 ZHANG You-jun;ZHU Xiang-li;SONG Wan-ping(School of Information Engineering,Shanghai Maritime University,Shanghai 201306,China)

机构地区：[1]上海海事大学信息工程学院,上海201306

出　　处：《微波学报》2023年第2期43-47,共5页Journal of Microwaves

基　　金：国家自然科学基金(61775196)。

摘　　要：针对插入损耗高和选择性低等问题,提出了一种具有圆形开路终端的新型谐振器拓扑结构。该结构将传统的U型发夹滤波器改成V型,在V型结构的终端引入圆形开路谐振器,并在开路枝节短截线上过孔。基于新型谐振器结构设计了一款尺寸为42.9 mm×36.54 mm(0.35λg×0.3λg)的带通滤波器。该滤波器具有插入损耗低、通带可控和远端优良等优点,并且采用新型谐振器之间的交叉耦合,在近端1 GHz附近产生一个传输零点,有效优化了阻带抑制和带通滤波器的选择性。仿真结果表明,带通滤波器的中心频率为1.7 GHz,3 dB的相对带宽为20%,最大回波损耗优于30 dB,最小插入损耗为0.20 dB,左边的带外抑制在50 dB以下,右边的带外抑制优于20 dB。实物测试结果与仿真结果基本一致,整体性能偏好,证明了该结构的可行性。To solve the problems of poor insertion loss and low selectivity,a new resonator topology with circular open circuit terminal is proposed.In this structure,the traditional U-shaped hairpin filter is changed into V-shape,a circular open circuit resonator is introduced at the end of the V-shaped structure,and a hole is drilled on the stub of the open circuit branch.Based on the new resonator structure,a 42.9 mm×36.54 mm(0.35λg×0.3λg)band-pass filter is designed.The filter has the advantages of low insertion loss,controllable passband and excellent far end,and uses cross coupling between new resonators to generate a transmission zero near the near end 1 GHz,which effectively suppresses the near end and optimizes the selectivity of the bandpass filter.The simulation results show that the center frequency of the filter is 1.7 GHz,the relative bandwidth of 3dB is 20%,the maximum return loss is better than 30 dB,and the minimum insertion loss is 0.20 dB.The out of band suppression on the left is below 50 dB and the out of band suppression on the right is better than 20 dB.The physical test results are basically consistent with the simulation results,and the overall performance preference proves the feasibility of the structure.

关 键 词：圆头谐振器 带通滤波器 交叉耦合 

分 类 号：TN713.5[电子电信—电路与系统] TN751.2