一种高抑制电调滤波器的设计与实现  

Design and Implementation of an Electrically Tunable Filter with High Suppression

作　　者：刘乐乐 刘兰 石玉[1] 吴治霖[3] 胡越 温杰 LIU Lele;LIU Lan;SHI Yu;WU Zhilin;HU Yue;WEN Jie(School of Microelectronics and Solid-state Electronics,University of Electronic Science and Technology of China,Chengdu 610054,China;The 29 th Institute of China Electronic Technology Group Corporation,Chengdu 610036,China;The 30 th Institute of China Electronic Technology Group Corporation,Chengdu 610041,China)

机构地区：[1]电子科技大学微电子与固体电子学院,四川成都610054 [2]中国电子科技集团公司第二十九研究所,四川成都610036 [3]中国电子科技集团公司第三十研究所,四川成都610041

出　　处：《电子科技》2019年第1期42-46,共5页Electronic Science and Technology

基　　金：国家自然科学基金(61471086)~~

摘　　要：针对超外差接收机中前端预选宽频段、低损耗与高带外抑制度的需求,文中在电感耦合方式的LC电调滤波器基础上,增加了寄生通带抑制滤波器,设计了一款基于20～800 MHz调谐范围的电调滤波器。通过实际测试得到在调谐范围内,滤波器插入损耗<1. 5dB,1 d B相对带宽约20%～30%,输入输出端口驻波<1. 5,二倍频处抑制度> 40d Bc,寄生通带抑制滤波器能将二次谐波和三次谐波寄生通带的抑制度分别提高40 d Bc和30 d Bc以上,从而利于滤波器在预选部分实现中频、镜频和本振反向等抑制作用。For the demand of wide frequency band,low loss and high external restriction in the front preselection of superheterodyne receiver,a filter was increased to suppress the spurious band behind the LC electrically tunable filter with inductance coupling method in the article,designing an electrically tunable filter on account of20~800MHz.Actual test showed that in the tuning range,insertion loss of the filter was less than1.5dB,1dB bandwidth was about20%~30%,VSWR of input and output ports were less than1.5,suppression on the second harmonic frequency was more than40dBc.The suppression on the spurious band was increased more than40dBc in the second frequency and more than30dBc in the third harmonic frequency after applying this filter.All these benefited to the filter with the intermediate frequency suppression,mirror frequency suppression,the reverse leakage of vibration suppression,and so on.

关 键 词：超外差接收机 宽频段 低损耗 高带外抑制度 电调滤波器 寄生通带 

分 类 号：TN61[电子电信—电路与系统]