一种高动态范围自动增益控制电路设计  

Design of AGC circuit with high dynamic range

作　　者：王燕君 徐英雷[2] WANG Yanjun;XU Yinglei(The Tenth Institute of China Electronic Technology Group Corporation,Chengdu 610036,China;School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]中国电子科技集团电子第十研究所,四川成都610036 [2]西南交通大学电气工程学院,四川成都610031

出　　处：《现代电子技术》2023年第2期19-22,共4页Modern Electronics Technique

基　　金：四川省重大科技专项项目:电子产品网络协同调试软件平台研发与应用(2022ZDZX0007)。

摘　　要：为使接收机在保证高灵敏度的情况下,适应接收端信号在很大范围内变化的需求,文中提出一种射频AGC和中频AGC相结合的四组AGC级联的完全反馈式AGC结构。首先阐述其设计思想并介绍关键电路与器件;其次,设计以国产集成芯片为核心器件的用于射频接收机的自动增益控制电路实现方案,通过对信道链路合理的增益分配、合理的器件选型,实现高于120 dB大动态范围的自动增益控制。采用该方案的实制品测试结果表明,其性能指标完全达到设计要求,在不同的频点都具有良好的电参数指标。文中方法能够解决大动态范围与高灵敏度、增益精确度、线性度等方面的矛盾,并克服早期接收机温度性能差、低温下易自激的问题,接收机稳定性得到显著增强;同时通过引入数字AGC思想,可应用于通信设备常规、跳频等多种工作方式。A full feedback AGC(automatic gain control)structure with four-group AGC cascade combining RF AGC and IF AGC is proposed to meet the requirements of the receiver signal changing in a large range while ensuring the high sensitivity of the receiver. The design idea is expounded,and the key circuits and devices are introduced in this paper. The implementation scheme of AGC circuit for RF receiver is designed,which takes the integrated chip made in China as the core device. The AGC with large dynamic range higher than 120 dB is realized by the reasonable gain distribution of channel link and reasonable device model selection. The testing results of actual products produced with this scheme show that the performance index of the product can fully meet the design requirements and the product has good electrical parameter indexes at different frequency points. The method proposed in this paper can resolve the contradiction between large dynamic range and high sensitivity,gain accuracy,linearity,etc.,and overcome the shortcomings of poor temperature performance and easy to cause self excitation at low temperature of the early receiver. Therefore,the stability of the receiver is enhanced significantly. By introducing the digital AGC idea,it can be applied to conventional,frequency hopping and other working modes of communication equipment.

关 键 词：AGC电路 射频接收机 电路设计 增益分配 器件选型 缺点克服 产品测试 

分 类 号：TN713-34[电子电信—电路与系统]