| 摘要 |
PURPOSE:To grasp by determining quantitatively the frequency and magnitude of level variance by providing a BPF, to which an object signal is inputted, and a switching circuit in the output side of this BPF and obtaining the relation between the fluctuating frequency of the auto power spectrum of the signal passing through them and the variation. CONSTITUTION:An input signal is inputted to a BPF1 and passes or does not pass a detector 3 selectively by a swich 2 on the output side of the BPF1. After the output passes through a LPF4, an A/D converter 5 and Fourier analyzer 6 to obtain the auto power spectrum, the output is sent to a calculator 7 and is subjected to a postprocessing operation and is outputted to an output device 8. The calculator 7 integrates the spectrum of the object frequency band to obtain an average value of the auto power included in this band with respect to time. In the spectrum of the level variation, the relative magnitude of the variance corresponding to the fluctuating frequency is expressed with a spectrum; and the variation of the object band level is attained when the result is displayed, and thus, the period of level variance of the signal and the magnitude of level variance are quantized unequivocally. |
