高中物理课本甲种本第三册图4-20收音机方框图中,检波后的波形是高频电流的波形。我认为这样编写有误。检波就是从经过调制的高频振荡电流中取出调制信号的过程。对于收音机来说,取出的是音频信号,所以检波后的波形是低频电流的波形,而不是高频电流的波形。检波过程,由检波电路的二极管单向导电和电容的滤波完成。其实,课本所示的波形是高频电流通过二极管后,未经电容滤波前的电流的波形。这过程不是检波的全过程。况且,这样的高频信号不能有效地通过低放级放大,也不能由低放级变成低频信号。建议将 High school physics textbook A third book Figure 4-20 radio block diagram, the waveform after the detection of high-frequency current waveform. I think this is a mistake. Detecting is the process of removing the modulated signal from the modulated high frequency oscillating current. For the radio, the audio signal is taken out, so the waveform after the detection is the waveform of the low-frequency current, not the waveform of the high-frequency current. Detection process, the detection circuit diode unidirectional conduction and capacitance filtering. In fact, the text shown in the waveform is the high-frequency current through the diode, the capacitor waveform before the filter current. This process is not the whole process of detection. Moreover, such a high-frequency signal can not effectively be amplified by a low-level amplifier or a low-level signal. Proposed to be