| 摘要 |
PROBLEM TO BE SOLVED: To provide a voltage-controlled oscillator small in size, and capable of realizing stable oscillations by inversely amplifying a control signal in response to a variable capacitor whose capacitance is varied with a control voltage signal, delaying the phase of the control signal and changing the frequency of the control signal, thereby correcting the phase change. SOLUTION: The capacitance of a variable capacitor VC is changed on the basis of a control voltage signal S84 and a control signal VC1, in response to the varied capacitance is fed to an inverting amplifier section 91, where the signal is inversely amplified. A phase adjustment output section 92 delays the phase of a control signal VQ2 outputted from the section 91 to correct a phase change resulting from changing a frequency of the control signal VC1. Thus, adjustment is made to obtain a large gain at a phase coincident point between a resonance signal (f) and the control signal VC1. Simultaneously, the resonance signal (f) outputted from SAWs 93, 94 is fed back surely to the inversion amplifier section 91. The control signal VQ2 with a desired frequency, in response to the control voltage signal S84, is oscillated as a carrier fC3. |
