| 摘要 |
PURPOSE:To prevent the drift of variable oscillator, by controlling the variable oscillator, based on the difference of the phase and frequency between the outputs of variable oscillator and reference oscillator. CONSTITUTION:The frequency difference between the output SR of a reference oscillator 2 and the output SO of a variable oscillator 5 is detected at a detection circuit 20 to obtain the detected output VD. On the other hand, the phase difference between the burst signal SB and the reference output SR is detected at a detecting circuit 3 to obtain the detected output VC. An addition circuit 21 reduces the output voltage VY by the voltage DELTAVD produced from the variation of the oscillation output SO when VC is constant. As a result, the frequency drift of a variable oscillator 5 can be compensated. |
