摘要
阻抗不匹配是微波射频电路设计中的一个重要问题,影响功率传输的大小,严重时可引起微波电路无法正常工作.为了消除反射,提高功率的传输效率,需要在微波组件间插入匹配网络,实现阻抗匹配.本文主要研究的是一种匹配纯电阻负载的阻抗匹配网络,称之为阻抗变换器.本文拟对耦合度C在30 dB左右,方向性D≥20 dB,S 11<-20 dB,频带宽±0.2 GHz和中心频率为5.8 GHz的矩形波导定向耦合器,设计一个阶梯式阻抗变换器,使之与BJ70接口匹配.分别设计与研究了四分之一波长阻抗变换器、二项式阻抗变换器和切比雪夫阻抗变换器三种阻抗变换器,总结了三种类型的阻抗变换器的适用场合,通过对比可知四分之一波长阻抗变换器的综合指标最好,最适合于本文所设计的定向耦合器的匹配网络.
Impedance mismatch is an important problem in the design of microwave RF circuits,which affects the size of power transmission and can cause microwave circuits to fail to work properly when severe.In order to eliminate reflections and improve the transmission efficiency of power,it is necessary to insert a matching network between microwave components to achieve impedance matching.The main study in this paper is an impedance matching network that matches pure resistive loads,called impedance transformer.In this paper,we propose to design a stepwise impedance transformer for a rectangular waveguide directional coupler with a coupling degree of C of about 30 dB,a directionality D≥of 20 dB,S 11<-20 dB,a frequency bandwidth of±0.2 GHz and a center frequency of 5.8 GHz,so that it matches the BJ70 interface.Three impedance transformer,namely one-quarter wavelength impedance transformer,binomial impedance transformer and Chebyshev impedance transformer,were designed and studied.Summarizing the applicable occasions of the three types of impedance transformer,the comprehensive index of the quarter-wavelength impedance transformer is best obtained by comparison,which is most suitable for the matching network of the directional coupler designed in this paper.
作者
黄勇
赵腾
王秀芳
HUANG Yong;ZHAO Teng;WANG Xiu-fang(School of Physical Science and Technology,Southwest Jiaotong University,Chengdu,Sichuan 610000,China)
出处
《大学物理》
2024年第1期57-63,共7页
College Physics
基金
西南交通大学2022年校级本科教育教学研究与改革重点项目(20220318)
西南交通大学2022年校级本科实验教学研究与改革重点项目(20221106)和一般项目(20222415)资助。
关键词
阻抗变换器
矩形波导
微波射频电路
阻抗匹配
impedance transformer
rectangular waveguide
microwave RF circuit
impedance matching
作者简介
黄勇(1999-),男,江西南昌人,西南交通大学物理学院2019级本科生;通信作者:王秀芳,E-mail:xwang66880@163.com。
