| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a frequency correcting circuit capable of easily and accurately outputting a frequency synchronized with the frequency of a transmission wave or a multiplied wave thereof. <P>SOLUTION: A frequency correcting circuit includes a first phase lock loop circuit 106 that generates with a first phase comparator 10 phase difference signals corresponding to the phase difference between the output signal of a first voltage control oscillator 16 and a reference oscillation signal and performs feedback control of oscillation by a first control oscillator 16 with a first oscillation control signal corresponding to a first phase difference signal via a first loop filter 12, and a second phase lock loop circuit 114 that generates with a second phase comparator 30 phase difference signals corresponding to the phase difference between the output signal of a second voltage control oscillator 36 and a comparison object signal and performs feedback control of oscillation by a second control oscillator 36 with a second oscillation control signal corresponding to a second phase difference signal via a second loop filter 32. The output signal is locked correspondingly to the comparison object signal by varying the second oscillation control signal correspondingly to the first oscillation control signal. <P>COPYRIGHT: (C)2012,JPO&INPIT |
