一种用于调幅接收机AGC的设计与实现

摘要

It is necessary to use an automatic gain control circuit to ensure that the output signal amplitude of the receiver is constant.In order to overcome the disadvantage of low efficiency of traditional design methods,a design method for fast automatic gain control in intermediate frequency receiver is proposed,which uses the joint adjustment in both the local oscillator and the intermediate frequency amplifier,and coupled with the fast automatic gain control algorithm,which can keep the audio output amplitude constant within the target range.The result shows that the adjustment time is reduced and the efficiency is improved.Based on theoretical analysis of the system,the computer simulation is conducted which indicate the feasibility of this method.Finally,the proposed method is proved by actual application.%在调幅接收机控制中,为使接收机输出信号的幅值恒定,通常需要对接收机进行自动增益控制,传统设计方法利用模拟环路来控制.提出一种用于数字控制的调幅接收机的快速自动增益控制的设计方法,通过对接收机本振AGC和中放AGC两级联合调节,加上快速自动增益控制算法,可以大大减小调节时间提高效率.在对系统进行理论分析的基础上,进行了仿真,与传统方法进行对比,说明了方法的可行性.最后将该方法应用于具体的项目实践,验证了理论分析的正确性和有效性.