| 摘要 |
PURPOSE:To prevent a carrier leakage from being caused by overlapping a part of a carrier onto an FM wave while being inputted to a modulator through the adjustment of feedback quantity by a feedback adjusting means. CONSTITUTION:A feedback adjusting means 18 is interposed between an adjusting terminal 11 and a resonance input terminal 13 of a 1-chip IC 20. That is, a signal fv' appearing at a resonance input terminal 13 with respect to a carrier fv given from a carrier oscillator 1 to a modulator 2 has the same frequency as that of the carrier fv and a proper phase difference. Then the feedback adjusting means 18 adjusts the feedback quantity to adjust the level of the signal fv', properly and the result is inputted to the adjusting terminal 11 as a feedback signal fv'' and superimposed on the FM wave, then a part of the carrier fv in the modulator 2 is cancelled by the feedback signal fv'', or added. Thus, the carrier fv of a proper level is given to the modulator 2 to avoid the production of carrier leakage.
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