一种AM信号解调方法的研究

Research on a Method of AM Signal Demodulation

实际应用中对于调幅波(AM)信号的解调不仅是要无失真地恢复出原始调制信号,还要能监测调幅度即调幅系数等参数。因此,阐述了一种AM信号解调的方法,对于AM信号的解调考虑到后续对于调制方式的识别和调幅系数的测量等,采用超外差方式中的下变频式,可将500 kHz~35 MHz载频的AM信号混频至中频100 kHz后经过检波放大电路不失真地解调出原始调制信号,调制信号频率范围在1~20 kHz。该方法由硬件模块实现,具有电路简单、调试方便和可扩展性强等优点,经过实际测试获得了良好的效果。

In practical applications,the demodulation of AM signals is not only to recover the original modulated signal without distortion,but also to monitor parameters such as amplitude modulation coefficient.Therefore,a method of AM signal demodulation is described.For the demodulation of AM signal,considering the subsequent identification of modulation mode and measurement of amplitude modulation coefficient,the down-conversion mode in the superheterodyne mode can be used to mix the AM signal with the carrier frequency of 500 kHz~35 MHz to the intermediate frequency of 100 kHz and demodulate the original modulation signal without distortion through the detection amplifier circuit.The frequency range of the modulation signal is from 1 to 20 kHz.This method is implemented by hardware modules and has the advantages of simple circuit,convenient debugging,and strong scalability.After practical testing,good results have been achieved.