紧凑型多陷波超宽带滤波器的设计  

Design of a compact UWB filter with multi-band notched characteristics

作　　者：刘文进[1] 赵泽慧 南敬昌[1] LIU Wenjin;ZHAO Zehui;NAN Jingchang(School of Electrics and Information Engineering,Liaoning Technical University,Huludao 125105,P.R.China)

机构地区：[1]辽宁工程技术大学电子与信息工程学院

出　　处：《重庆邮电大学学报（自然科学版）》2019年第6期818-825,共8页Journal of Chongqing University of Posts and Telecommunications(Natural Science Edition)

基　　金：国家自然科学基金(61372058);辽宁省高校重点实验室项目(LJZS007)~~

摘　　要：针对传统带阻单元构成滤波器存在陷波深度不足和阻带抑制较差的问题,提出一种加载开路枝节的多陷波超宽带滤波器.基于开路枝节线和阶跃阻抗谐振器理论,通过在超宽带滤波器多模谐振器上引入一对折叠开路枝节线产生2个陷波频段,这种特殊枝节实现的陷波抑制能力更强;在超宽带结构下方耦合阶跃阻抗谐振器产生第3个陷波频段,陷波深度更好.最终实现超宽带带通滤波器的中心频率为6.6 GHz,陷波频段相对带宽约为134%.仿真与实测结果表明,该滤波器工作带宽为2.2~11.2 GHz,实现了2.8~4.4 GHz,6.2~6.8 GHz和8.8~9.8 GHz 3个频段的陷波特性,可有效滤除C波段和WLAN频段信号对超宽带通信系统的干扰.满足超宽带系统对陷波滤波器插入损耗和带外抑制的要求.Aiming at the problem that the notched depth is insufficient and the stop band suppression is bad in the filter composed by traditional band stop units a multi band notched characteristics ultra wideband(UWB)filter structure with open circuited stub is proposed.Based on the theories of open circuited stub and step impedance resonator two notch bands are produced by adding a pair of folded open circuited stub on the multi mode resonator of the UWB filter.The special stub can realize stronger notch suppression capability.The third notched band is produced by coupling a step impedance resona tor below the UWB structure which makes the depth of the notched band preferable.Ultimately the center frequency of UWB bandpass filter is 6.6 GHz the relative bandwidth of the notched band is about 134%.Simulated and measured re sults show that the filter has a working bandwidth of 2.2 GHz^11.2 GHz it realizes band notched characteristics of triple frequencybandsat2.8GHz^4.4GHz 6.2GHz^6.8GHzand8.8GHz^9.8GHz whichcanefficientlyeliminatethein terfere of C band and WLAN band signals on UWB communication systems.It meets the requirements of insertion loss and out of band rejection of notch filter in UWB system.

关 键 词：超宽带滤波器 陷波特性 开路枝节线 多模谐振器 

分 类 号：TN713[电子电信—电路与系统]