A VOLTAGE-CONTROLLED OSCILLATOR WITH WIDE FREQUENCY RANGE AND LINEAR RELATIONSHIP BETWEEN CONTROL VOLTAGE AND OSCILLATION FREQUENCY

摘要

A voltage-controlled oscillator with wide frequency range is provided to increase the range of oscillation frequency by increasing variable capacitance by a plurality of MOS transistors connected to a LC resonance circuit. In a voltage-controlled oscillator, an LC resonance circuit(230) oscillates a frequency according to a control voltage and an amplifier circuit(250) amplifies the oscillation frequency. The LC resonance circuit includes a first and a second inductor, a variable capacitance unit, and a second variable capacitance(220). The first capacitance unit has a first and second varator which are connected with each other in parallel. The first variable capacitance has a first capacitance according to a first control voltage, and second variable capacitance has a firs and a second transistor which are connected with the varator in parallel and it has a second capacitance according to a second control voltage.