| 摘要 |
A phase signal estimator receives a first phase signal having a first frequency and generates a first filtered signal phase-locked with the first phase signal as an estimated phase signal. A phase locked loop section receives a second phase signal having a second frequency which corresponds to a predetermined multiple of the first frequency of the first phase signal, and outputs a second filtered signal phase-locked with the second phase signal as a desired phase signal. In the phase locked loop section, a phase comparator receives the second phase signal and the desired phase signal and generates a phase difference signal. A filter low-pass filters the phase difference signal from the phase comparator. A signal generator generates a signal having a predetermined frequency in accordance with the output from the filter. A phase adder adds the signal having the predetermined frequency from the signal generator and the estimated phase signal from the phase signal estimator and outputs the desired phase signal. A frequency compensator is selectively connected to the estimated phase signal, the second phase signal, and the desired phase signal so that the phase locked loop section has substantially the same low-pass filtering response characteristic as the first frequency of the first phase signal. |
