双模式宽带程控增益放大器模块设计  

Design of dual-mode wideband programmable gain amplifier module

作　　者：张家田[1] 秦宏伟 严正国[1] ZHANG Jiatian;QIN Hongwei;YAN Zhengguo(Shaanxi Key Laboratory of Oil and Gas Well Measurement and Control Technology,Xi’an Shiyou University,Xi’an 710065,China)

机构地区：[1]西安石油大学陕西省油气井测控技术重点实验室,陕西西安710065

出　　处：《现代电子技术》2022年第2期62-66,共5页Modern Electronics Technique

基　　金：陕西省教育厅重点实验室科研计划项目(15JS097)。

摘　　要：在信号检测领域中,由于原始信号的动态范围较大,往往需要把增益放大,为了使放大器实现程控增益放大,文中提出双模式宽带程控增益放大器模块设计。该程控增益放大器模块采用双模式方式工作,即固定增益输出可变模式和固定输出增益可变模式。模块使用STM32F4O7作为微控制器(MCU),MCU与多级可变增益放大器和峰值检测电路构成闭环控制,形成自动增益控制电路。首先对峰值检测电路输出的信号进行A/D采集,经过D/A反馈使得整个模块处于动态平衡状态,这种闭环控制系统能够精确地控制增益和输出信号。最后利用均值滤波算法测试得到实验数据。实验结果表明该模块能够在1 kHz~20 MHz频率范围内实现-20~60 dB的增益控制;固定增益时,增益相对误差在3%以内;固定输出电压时,电压相对误差在3%以内。此模块达到了宽带、高精度和高增益的性能指标,较传统模块而言,其优势在于将三者性能指标同时兼顾并优化,性能指标不再单一,也为程控增益放大器模块集成化奠定基础。In the field of signal detection,due to the large dynamic range of the original signal,it is often necessary to amplify the gain.In order to realize the programmable gain amplification of the amplifier,a dual-mode wideband programmable gain amplifier module design is proposed in this paper.The programmable gain amplifier module works in two modes:fixed gain output variable mode and fixed output gain variable mode.In the module,the STM32F407 is used as a microcontroller(MCU),the MCU,multi-stage variable gain amplifier and peak detection circuit are used to make up a closed-loop control to form an automatic gain control circuit.The A/D acquisition of the signal output by the peak detection circuit is performed,and then the D/A feedback is taken to make whole module in a dynamic balance state.This closed-loop control system can accurately control the gain and output signal.The mean filtering algorithm is used to test the experimental data.The experimental results show that the module can achieve-20~60 dB gain control in the frequency range of 1 kHz~20 MHz;When the gain is fixed,the relative error of gain is less than 3%;When the output voltage is fixed,the relative error of voltage is less than 3%.This module achieves the performance indexes of broadband,high precision and high gain.In comparison with the traditional module,the advantage of this module is to take into account and optimize the three performance indexes at the same time.The performance index is no longer single,and it also lays the foundation for the integration of programmable gain amplifier module.

关 键 词：程控放大器 固定增益 输出信号采集 峰值检测 自动增益控制 闭环控制 

分 类 号：TN722.7-34[电子电信—电路与系统]