具有宽阻带特性的UHF频段高温超导宽带滤波器研究  

DESIGN OF A HTS WIDEBAND FILTER AT UHF BAND WITH A WIDE UPPER STOPBAND

作　　者：李明杰[1] 曹必松[1] 张晓平[1] 魏斌[1] 郭旭波[1] 卢新祥[1] 张盈[1] 

机构地区：[1]清华大学物理系,北京100084

出　　处：《低温物理学报》2010年第5期350-354,共5页Low Temperature Physical Letters

基　　金：国家自然科学基金(批准号:60871004)资助的课题

摘　　要：本文提出了一种新型的1/4波长折叠指形谐振器,该谐振器不仅能够以紧凑的耦合结构实现强耦合,并且还能抵消2倍频的寄生通带.采用这种谐振器设计出了中心频率为310MHz、相对带宽为26%的8节高温超导宽带滤波器.同时为了进一步抑制3倍频寄生通带、拓宽阻带范围,本文还设计出了后端级联用的折叠交指低通滤波器.通过综合优化仿真,设计并制作出具有宽阻带性能的UHF频段高温超导宽带滤波器.测试结果表明,该高温超导滤波器在无需调谐情况下,带内插损低于0.20dB,带内反射损耗优于15dB,在3.3倍基频(f0)范围内带外抑制达到70dB以上.In this paper,a novel quarter-wavelength interdigital-like resonator is proposed,which can both realize strong coupling with compact structure and suppress the second spurious harmonic. Using this resonator,an eight-pole high temperature superconducting （HTS） filter is designed with a center frequency of 310 MHz and a fractional bandwidth of 26%. In addition,a folded interdigital lowpass filter is designed and added in order to suppress the third spurious harmonic and achieve a wideband spurious suppression. With optimal design of the cascaded filter,a wideband filter with a wide upper stopband is developed. The measurements show that,without tuning,the insertion loss of the filter is less than 0.2dB,the return loss is better than 17dB,and the out-of-band rejection is better than 70dB within 3.3 times the filter center frequency.

关 键 词：高温超导滤波器 1/4波长折叠指形谐振器 折叠交指低通滤波器 宽带 宽阻带 

分 类 号：TN713[电子电信—电路与系统]