基于后匹配结构的Doherty功率放大器的设计  

Design of Doherty Power Amplifier Based on Post-matching Structure

作　　者：代法亮 李军[1] 尹希雷 朱佳垟 DAI Fa-liang;LI Jun;YIN Xi-lei;ZHU Jia-yang(Faculty of Electrical Engineering and Computer Science,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学信息科学与工程学院,宁波315211

出　　处：《无线通信技术》2020年第2期36-40,共5页Wireless Communication Technology

基　　金：国家自然科学基金面上项目(61571251);宁波市自然科学基金(2018A610024);浙江省公益技术研究项目(LGG20F010001)。

摘　　要：由于传统Doherty功率放大器存在诸多限制带宽的因素,本文通过后匹配结构代替传统Doherty功放四分之一波长线阻抗逆变器并且在饱和时将功放匹配到一个较低的阻抗值来减弱传统Doherty功放的宽带限制因素。此外还采用了阶跃阻抗低通滤波器做为主辅功放的输出匹配结构来扩展Doherty功放的带宽。设计中采用安捷伦公司的先进设计系统软件(advanced design system,ADS),选取Cree公司CGH40010F GaN HEMT晶体管。经过电路仿真和实物测试,最终实现了在3.2-3.6GHz饱和输出功率44dBm、漏极效率72%、增益9.5-15dB,回退6dB漏极效率在48%-56%。Because there are many factors that limit the bandwidth of traditional Doherty,this paper replaces the traditional Doherty quarter-wavelength line impedance inverter with a post-matching structure,and matches the power amplifier to a lower impedance value when saturated,use these two methods to weaken the bandwidth limitations of traditional Doherty.In addition,a step impedance low-pass filter is used as the output matching structure of the main auxiliary power amplifier to expand the bandwidth of the Doherty power amplifier.In the design,Agilent’s advanced design system(ADS)was used,and Cree’s CGH40010 F GaN HEMT transistor was selected.After circuit simulation and physical testing,it finally achieved a saturation power of 44 dBm at 3.2-3.6 GHz,a drain efficiency of 72%,a gain of 9.5-15 dB,and a 6 dB back-off drain efficiency of 48%-56%.

关 键 词：功率放大器 DOHERTY 阶跃阻抗低通滤波 后匹配 

分 类 号：TN925[电子电信—通信与信息系统]