DUAL MODE OSCILLATOR USING VARIABLE CAPACITANCE ELEMENT FOR PERFORMING SPONTANEOUS RESONANCE OPERATION

摘要

PURPOSE: A dual mode oscillator using a variable capacitance element for performing a simultaneous resonance operation is provided to reduce largely a size of a circuit by using only one resonant part to perform a simultaneous resonance operation of two different frequencies. CONSTITUTION: A signal oscillator includes a resonant part(30) for generating a resonant frequency signal and an oscillation part(40) for oscillating the resonant frequency signal. The resonant part includes a variable capacitance element and a switch for applying a reverse voltage to the variable capacitance element. The switch is used for performing a switching operation to change the capacitance of the variable capacitance element. Two different frequencies resonate by the change of the capacitance of the variable capacitance element.