Compact wide stopband superconducting bandpass filter using modified spiral resonators with interdigital structure

作     者：吴荻 魏斌 李博 郭旭波 卢新祥 曹必松 Di Wu;Bin Wei;Bo Li;Xu-Bo Guo;Xin-Xiang Lu;Bi-Song Cao

作者机构：State Key Laboratory of Low-Dimensional Quantum Physics Department of Physics Tsinghua University Department of Physics and Electronic Engineering Shaoxing University 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2018年第27卷第6期

页      面：513-517页

核心收录：

学科分类：07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：supported by the National Key Scientific Instrument and Equipment Development Project,China(Grant No.2014YQ030975) the National Natural Science Foundation of China(Grant Nos.61371009 and 61401282) 

主　　题：high-temperature superconducting bandpass filter microstrip filter wide stopband 

摘      要：In this study, we propose a novel resonator that is composed of a modified spiral with an embedded interdigital capacitor. A large ratio of the first spurious frequency to the fundamental resonant frequency is obtained, which is suitable for the design of filters with wide stopbands, and the circuit size is considerably reduced by embedding the interdigital structure in the spiral. For demonstration, a compact four-pole high temperature superconducting（HTS） filter with a center frequency of 568 MHz is designed and fabricated on double-sided YBCO film with a size of 11.4 mm×8.0 mm. The filter measurement shows excellent performance with an out-of-band rejection level better than 60.9 dB up to 3863 MHz.