一、问题差拍现象源于声学,通常指两个频率相接近的声波合成,结果人们听到有强弱变化次数等于两个频率之差的声音。后来这种现象所反映的基本原理又推广到振动理论中,当两个同向频率相接近的振动合成时,合成振动的振幅变化次数等于两个频率之差。随着技术上的进步和发展,差拍原理也应用到无线电技术上来。可是多年来一些书刊上把超外差式接收机中 First, the phenomenon of poor shootings from the acoustics, usually refers to the two frequencies close to the sound synthesis, the result people hear the number of changes in the intensity equal to the difference between the two frequencies of sound. Later, the basic principle reflected by this phenomenon was generalized to the vibration theory. When two vibrations with the same frequency are close to each other, the number of times of the amplitude of the synthesized vibration is equal to the difference between the two frequencies. As the technology advances and develops, the beat principle is also applied to the radio technology. But over the years some books on the super-heterodyne receiver