Patent ID: 8076982

Claim:
A voltage-controlled variable frequency oscillation circuit, comprising: an oscillation circuit section including a resonance circuit which includes a coil and a variable capacitance element, and a negative resistance circuit; and a first resistor connected between the resonance circuit of said oscillation circuit section and a first one of a pair of terminals of a power supply, wherein said first resistor includes a plurality of resistance elements and a plurality of switch circuits, said switch circuits being individually controlled with a controlling signal between on and off to variably control the resistance value of said first resistor ; a second resistor connected between the negative resistance circuit of said oscillation circuit section and a second one of the terminals of the power supply, wherein both of said first resistor and said second resistor have a variably controllable resistance value, and wherein both of said first resistor and said second resistor are formed from a plurality of resistance elements and a plurality of switch circuits, and said switch circuits are individually controlled between on and off to variably control the resistance value of said first and second resistors.