| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable highly accurate wander measurement with a simple circuit configuration. <P>SOLUTION: Sine wave generation parts 4a, 4b respectively output sinusoidal voltage signals u1(t), u2(t) with a signal to be measured and a reference signal comprising a clock signal as an operation clock. A phase demodulation part 6 outputs a time difference sequence x(n) based on instantaneous phase difference between sequences u1(n), u2(n) obtained by sampling the two sinusoidal voltage signals u1(t), u2(t) at fixed cycles. A control part 8 sets frequency tuning words FTW1, FTW2 closest to a specified output frequency f0 in a pair of sine wave generation parts 4a, 4b on the basis of a nominal frequency of the signal to be measured and a nominal frequency of the reference signal which are set in advance, controls the output frequencies of the two sinusoidal voltage signals u1(t), u2(t), and suppresses a measurement error resulting from circuit noise. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
