| 摘要 |
PURPOSE:To obtain easily an angle modulated signal having a stable frequency by applying reference frequency signal to a control circuit from a reference oscillator in order to fix the reference frequency of the angle modulated signal. CONSTITUTION:The signal to be modulated is applied to an adder 5 from an input terminal 6, and the adder adds this signal to a feedback signal given from an LPF9 constituting a control circuit 3 to apply them to a voltage control type oscillator 4. The oscillator 4 gives a defection to the oscillation frequency according to said addition signal and delivers an angle modulated signal via an output terminal 7. At the same time, the angle modulated signal is applied to a phase comparator 8. The comparator 8 supplies the angle modulated signal and a reference frequency signal given from a reference oscillator 2 and detects the phase angle difference of both signals. This phase angle difference signal is supplied to the adder 5 via the LPF9. In such a constitution, it is possible to obtain easily an angle modulated signal having a stable reference frequency from the oscillator without giving a special frequency stabilizing counterplan to the oscillator 1 itself. |
