高效率doherty功率放大器研究.pdf

摘要摘要功率放大器作为无线通信系统重要组成部分广泛用于移动通信、卫星通信、雷达系统等领域中。尤其当传输信号的峰均功率比很大时,为了保证通信质量, 功率放大器回退工作,效率很低。不仅造成了电能严重浪费,而且散热问题导致系统使用寿命缩短。因此,在功率回退条件下,提高功率放大器效率,能够节约能源,降低功耗。高效率功率放大器已经成为现阶段研究的热点问题。本研究基于Doherty结构功率放大器展开。理论分析经典Doherty功率放大器工作原理以及影响其效率和线性度的因素。基于NXP公司LDMOS功率晶体管 BLF6G10-200RN,设计出用于多载波GSM直放站的100W Doherty功率放大器, 并且加工调试完成。仿真设计过程中详细研究了补偿线和栅极电压对Doherty功放效率、增益和线性度的影响。实际测量Doherty功放在输出功率为50dBm(回退6dB)时,%,。理论分析并联电容、并联电路和2/4传输线三种E类功放的工作特性。基于 GaN功率晶体管NPTB0025,设计了工作频率为1GHz的并联电容E类功放和3,/4 传输线E类功放,,%%。两种E类Doherty功放输出功率为40dBm()时,%和 %。E类Doherty功放提高了Doherty功放在功率回退时的效率。数据比较表明,并联电容E类功放较2/4传输线E类功放更适合用于Doherty结构。关键词:Doherty,功率放大器,E类,效率 ABSTRACT ABSTRACT As an important equipment in munication systems,the power amplifier(PA)is widely used munications,munications,and thesignals have an high peak toaverage power ratio,the PA should work backed offfrom P dB inorder to ensure munication not only causes a serious waste ofenergy,but also gives thesystem a shorter life because ,improving efficiency ofpower amplifier atpower back-off condition can save energy and reduce power —efficiency PA e ahotissue atthepresent stage ofresearch. Inthispaper,we focus onthestudy ofDoherty power theClass E amplifier is used inDoherty structure toimprove efficiency atthe power backoff. Firstly,we analyze theworking principle ofDoherty PA theoretically and thefactors which impact efficiency 0-200RN which ismanufactured by NXP Corporation isused todesign Doherty PA which works formulti— thesimulation,we study theimpact ofoffsetlineand gatevoltage on efficiency,gain and linearity ofDoherty PA measurement results show the Doherty PA exhibits adrain efficiency %at 50-dBm output power (6dBback-off),and theIM3 is一33dBc T1:lispaperanalyzes theoperation characteristics ofshunt capacitor Class E, parallel circuits Class E and2/4 trans