高精度可变增益放大器的研究与设计  

Research and Design of High-attenuation-accuracy Variable Gain Amplifier

作　　者：吴奕蓬 黄晴 杜琳 王涛 陈仲谋 徐建辉 张博 WU Yipeng;HUANG Qing;DU Lin;WANG Tao;CHEN Zhongmou;XU Jianhui;ZHANG Bo(Xi'an Bonray Integrated Information Electronics Co.,Ltd.,Xi'an,710121,CHN)

机构地区：[1]西安博瑞集信电子科技有限公司,西安710121

出　　处：《固体电子学研究与进展》2023年第5期430-435,共6页Research & Progress of SSE

基　　金：陕西省重点研发计划资助项目(2018ZDXM-GY-010,2017ZDXM-GY-004,2016KTCQ01-08);西安市集成电路重大专项资助项目(201809174CY3JC16);陕西省创新人才推进计划-科技创新团队资助项目(2020TD-019);陕西省教育厅重点科学研究资助项目(20JY059)。

摘　　要：为了实现可变增益放大器高精度及大动态范围的优势,基于GaAs 0.25μm pHEMT工艺,设计了一款工作在0.1~4.0 GHz并行控制的可变增益放大器。放大器由数控衰减器和射频放大器组成。数控衰减单元采用桥T型结构和电平转换电路来实现;正压控制衰减电路简化了电路结构,提高电路可靠性;改进型并联电容补偿衰减结构改善大衰减态高频衰减精度;射频放大器电路采用并联电阻负反馈的共源共栅(Cascode)结构,实现了高增益平坦度和大动态范围。测试结果显示,在工作频带内,可变增益放大器的增益可达20 dB以上、平坦度在1.5 dB以内,可变增益范围为0~31.5 dB、衰减步进0.5 dB,输出三阶交调点最高可达39 dBm,端口回波损耗均小于-15 dB。In order to achieve the advantages of high precision and large dynamic range of variable gain amplifier,a high precision variable gain amplifier with parallel control operating in 0.1-4.0 GHz was designed based on a 0.25μm GaAs pHEMT process in this paper.The variable gain amplifier consisted of a digital attenuator and a RF amplifier.Bridge T-shape structure and level conversion circuit were used to achieve digital attenuation unit.Positive voltage control circuit was adopted to simplify the attenuator circuit and improve the reliability of the circuit.Improved parallel capacitor compensation attenuation structure was introduced to optimize the high frequency attenuation accuracy of large attenuation state.The RF amplifier adopted common-source-common-gate(Cascode)structure with parallel resistance negative feedback,which achieves good gain flatness and large dynamic range.The measurement results show that from 0.1 GHz to 4.0 GHz frequency band,the gain is more than 20 dB,and the gain flatness within 1.5 dB.The attenuation step is 0.5 dB,the variable gain range is 0-31.5 dB,the output third order crossover point can reach up to 39 dBm and the port return loss is less than-15 dB.

关 键 词：可变增益放大器 数控衰减器 正电压控制 高衰减精度 

分 类 号：TN722.5[电子电信—电路与系统]