PURPOSE: To dispense with a phase comparator and to make complicated adjustment unnecessary, by inputting an input signal to a frequency converting part, a band-pass filter, an A/D converter and a plurality of fast Fourier transform operators to perform operation.
CONSTITUTION: A plurality of input signals xao(t), xbo(t) are converted in frequency on the basis of the same frequency variable local oscillator signal in a frequency converting part 20. The frequency converted signals are inputted to A/D converters 31a, 31b through the third band pass filters 30a, 30b to respectively convert the signals of a predetermined frequency component to digital signals. The output signals of the A/D converters 31a, 31b are respectively subjected to fast Fourier transform operation by fast Fourier transform operators 32a, 32b to output calculated values which are, in turn, displayed on a display part 35.
NAKATSUGAWA KENJI
KATAYAMA AIICHI
NAKAMURA HISAFUMI
| JPS6129770A | 1986-02-10 | |||
| JPS5930068A | 1984-02-17 | |||
| JPS62285068A | 1987-12-10 |
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