Patent ID: 7106236

Claim:
An analog-to-digital converting method for converting an analog signal into a digital signal by using a plurality of analog-to-digital converters, wherein phases of sampling clocks applied to said plurality of analog-to-digital converters differ by a predetermined period, comprising: a measuring step of measuring a frequency characteristic of each of said analog-to-digital converters in advance; a sampling step of sampling the analog signal by using said plurality of analog-to-digital converters; a Fourier transformation step of performing Fourier transformation on the data sampled by each of said plurality of analog-to-digital converters and generating a plurality of frequency domain signals corresponding to said plurality of analog-to-digital converters; a correcting step of converting each of the frequency domain signals into a signal to be acquired in case that the frequency characteristic of said corresponding analog-to-digital converter is ideal, by multiplying each of the frequency domain signals by a correction coefficient determined on the basis of the frequency characteristics of all said analog-to-digital converters; and a synthesizing step of synthesizing each of the frequency domain signals acquired at said correcting step and generating a frequency spectrum of the digital signal.