一种宽带高效包络跟踪放大器的设计  

Design of a Wide-Band and High-Efficiency Envelope Tracking Amplifier

作　　者：王巍[1] 莫啸 蔡文琪[1] 胡凤[1] 王明耀[1] 王冠宇[1] 袁军[1] 杨正琳[1] 

机构地区：[1]重庆邮电大学光电工程学院/国际半导体学院,重庆400065

出　　处：《微电子学》2016年第2期165-169,共5页Microelectronics

摘　　要：为了高效处理宽带非恒包络信号,利用宽带包络信号功率主要集中在低频部分的特性,结合线性放大器和开关类放大器的优势,设计了一个宽带包络跟踪放大器。该放大器由一个宽带线性级和一个受线性级控制的高效开关级组成。线性级采用折叠式共源共栅放大器结构,具有AB类输出级及输出级缓冲;开关级采用同步降压型DC-DC变换器结构,包含驱动电路及"防直通"模块。整个电路采用Jazz 0.18μm BiCMOS工艺进行设计仿真,结果表明,在3.3V电源电压下,线性级单位增益带宽约为50MHz,可驱动300mA电流,具有188V/μs的摆率,包络跟踪放大器可跟踪包络信号幅度和带宽的瞬时变化,改变开关导通比以及开关频率。In order to process the non-constant envelope signal efficiently,a wide-band envelope tracking amplifier was proposed through considering the features that most of the power of the wide-band envelope signals would concentrate in the low frequency,and taking the advantages of linear amplifier and switch amplifier.The proposed wide-band envelope tracking amplifier consisted of a wide-band linear stage and a high-efficiency switch stage controlled by the linear stage.The linear stage was based on a folded cascode amplifier structure with a class AB output stage and an output stage buffer.The switch stage was based on a synchronous buck DC-DC converter structure with a driving circuit and an＂anti-through＂module.The whole circuit was designed and simulated in Jazz0.18μm BiCMOS process.The simulation results showed that the bandwidth of the linear stage under unity gain was about 50 MHz,the driving current was 300 mA,the slew rate was 188V/μs at a 3.3Vsupply voltage.When the switch conduction ratio and the switch frequency were changed,the proposed tracking amplifier could track the instantaneous changes of the envelope signal’s amplitude and bandwidth.

关 键 词：非恒包络信号 包络跟踪放大器 宽带线性级 高效开关级 

分 类 号：TN433[电子电信—微电子学与固体电子学]