一、基本原理及測量范圍: 本頻譜分析仪是差頻式的具有頻率选擇性的电压表与示波器,因此它可以直讀及直观周期性脉冲訊号頻諧的相对值及圖象。人們为了分析出訊号的頻譜在理論上而言,可以借一选擇性很高的諧振迴路,使諧振于訊号基頻或諧頻,并从迴路元件上取出其不同頻率电压,但实际上既具有高选擇性又具有寬的可变頻率的諧振迴路是不易做到的,因此,只能将迴路自然頻率固定,而用差 First, the basic principles and measurement range: The frequency spectrum analyzer is a frequency-selective frequency meter with an oscilloscope, so it can directly read and intuitive periodic pulse frequency of the relative value of harmonic and images. In order to analyze the frequency spectrum of the signal, in theory, a highly selective resonant circuit can be used to make it resonate with the fundamental frequency or the harmonic frequency of the signal and take out the different frequency voltages from the circuit components. However, in practice On both the high selectivity and has a wide variable frequency resonant circuit is not easy to achieve, therefore, only the loop natural frequency fixed, and poor