Patent ID: 8004268

Claim:
A signal measuring device comprising: an interpolated signal generating circuit which receives discrete signals as measurement targets and generates signals interposing in between two consecutive discrete signals to output the thus generated signals; and a measuring circuit which receives the interpolated signals output from said interpolated signal generating circuit, and outputs results obtained by measuring the interpolated signals, wherein said interpolated signal generating circuit comprises a first N phase clock conversion circuit, N is an integer not less than 2, and a second N phase clock conversion circuit, said first N phase clock conversion circuit receives first clock signals, and generates N interpolated signals including a first interpolated signal to an Nth interpolated signal by interpolating a phase difference between two consecutive first clock signals with k:N−k, k are all integers from 1 to N, said second N phase clock conversion circuit receives second clock signals equal in average period to the first clock signals, and generates N interpolated signals including a first interpolated signal to an Nth interpolated signal by interpolating a phase difference between two consecutive second clock signals with k:N−k, and the measuring circuit receives a first interpolated signal to an Nth interpolated signal from said first N phase clock conversion circuit and said second N phase clock conversion circuit, and measures and outputs phase differences between interpolated signals with the same numbers.