高灵敏度入侵检测系统接收机射频前端设计

Design of Intrusion Detection System RF Front End with High Sensitivity

针对泄漏电缆入侵检测系统接收信号微弱、易受环境影响等问题,提出一种新型高灵敏度、大增益的直放式接收机射频前端电路,优化放大增益和噪声系数,提高系统稳定性,其结构以宽带带通滤波器、超低噪声放大器CMA5043、固定增益模块Hmc580、自动增益控制模块(AGC)AD8331为核心。实验结果表明,在26.25-36.25MHz通带内,滤波器的插入损耗小于1.4dB,电路噪声系数小于1.1dB、可识别的最小信号Smin为-118dBm,实现80-100dB增益可调,系统工作稳定。

Aiming at the problem of weak signal reception and susceptibility to environmental impact of the leakage cable intrusion detection system,we propose a new type of high sensitivity and high gain direct receiver RF front end circuit to optimize the amplification gain and noise figure,and improve the stability of the system.The structure is based on broadband band-pass filter,ultra-low noise amplifier CMA5043,fixed gain module Hmc580,automatic gain control module（AGC）AD8331.The experimental results show that,in the 26.25-36.25 MHz passband,the filter insertion loss less than 1.4db,circuit noise figure less than 1.1dB,the minimum signal Smin is-118 dBm,and the gain is 80-100 dB,The system works stably.