一种双传输零点电调滤波器的设计与实现  

Design and implementation of a double transmission zero-point electrically tunable filter

作　　者：张博 李虎斌 ZHANG Bo;LI Hubin(School of Electronic Engineering,Xi􀆳an University of Posts&Telecommunications,Xi􀆳an 710121,China)

机构地区：[1]西安邮电大学电子工程学院,陕西西安710121

出　　处：《电子元件与材料》2021年第3期257-261,共5页Electronic Components And Materials

基　　金：陕西省西安市集成电路重大专项(201809174CY3JC16);陕西省重点研发计划(2017ZDXM-GY-004);陕西省教育厅地方产业化专项(15JF029);陕西省创新人才推进计划-科技创新团队(2020TD-019);陕西省技术创新引导专项(2017ZKC02-56)。

摘　　要：为了解决无线电台射频前端预选滤波器低插损、高抑制的需求,采用一种变形的耦合谐振式带通滤波器,设计了一款高性能的LC电调滤波器。通过混合电磁耦合原理在两个谐振回路之间和电感耦合单元上分别引入并联电容,使得带通滤波器在左右两端引入传输零点,改善带外衰减性能。通过电路仿真以及实物测试,设计出30~512 MHz调谐范围的电调滤波器。实测结果表明,滤波器插入损耗小于1.5 dB,1 dB相对带宽大于10%,驻波比小于2∶1,由于传输零点的存在,使得电调滤波器在二倍频处具有极大的带外抑制性能,与仿真结果基本吻合。In order to meet the requirements of low insertion loss and high rejection of radio frequency front-end pre-filter,a deformed coupled resonant bandpass filter was adopted to design a high performance LC electrically tunable filter.By introducing the parallel capacitance between two resonant circuits and inductive coupling unit with the principle of hybrid electromagnetic coupling,the transmission zero point was introduced at the left and right ends of the bandpass filter and the out-of-band attenuation performance was improved.Through the circuit simulation and physical measurement,an electrically tunable filter with a tuning range of 30-512 MHz was realized.The experimental results show that the insertion loss of the filter is less than 1.5 dB,the relative bandwidth of 1 dB is more than 10%,and the standing wave ratio is less than 2∶1.Due to the existence of transmission zeros,the electrically tunable filter has great out-of-band suppression performance at the double frequency,which is basically consistent with the simulation results.

关 键 词：耦合谐振 电调滤波器 混合电磁耦合 传输零点 

分 类 号：TN713[电子电信—电路与系统]