| 摘要 |
PURPOSE: To grasp the property of the high-frequency signal including noises accurately and to clarify the designing guideline for a band-pass filter by providing a difference-frequency detecting step, a correlation-dimension operating step and the step for estimating the correlation dimension. CONSTITUTION: The intermediate frequency signal from a band-pass filter 306 is digitized in an A/D converter 307 and supplied into an operation processing device 308. The device 308 computes the correlation dimension (fractal dimension) of the digital signal and the dispersion of the dimension. A controller 309 controls the passing frequency band of the filter 306 so that the dispersion computed by the device 308 becomes the minimum value. The correlation dimension is the index for measuring the standard of the freedom for specifying the motion in the time series of phenomenon. The correlation dimension is obtained by the scaling rule of manifold pattern (graphic form), which is constituted from the time series. In the actual measurement, it is difficult to measure the fluctuation of the high frequency directly. Therefore, the value of the correlation dimension is estimated based on the fluctuation of the intermediate frequency signal obtained by heterodyne detection. |
