Patent ID: 7719372

Claim:
A voltage controlled piezoelectric oscillator comprising a variable capacitance unit that changes a capacitance value according to an external control voltage, said variable capacitance unit comprising: a first variable capacitance diode; a first condenser connected in parallel with said first variable capacitance diode; a second variable capacitance diode; a second condenser inserted and connected between a cathode of said first variable capacitance diode and an anode of said second variable capacitance diode; a third condenser inserted and connected between an anode of said first variable capacitance diode and a cathode of said second variable capacitance diode, wherein said external control voltage is applied to one end of said first variable capacitance diode and one end of said second variable capacitance diode, respectively, so that said one end of said first variable capacitance diode and said one end of said second variable capacitance diode differ in polarity from each other.