Patent ID: 8076985
Filing Date: 2011-12-13
Classification: H03B,H03L

Abstract:
1. A voltage-controlled oscillator that generates a local oscillation signal, the voltage-controlled oscillator comprising: an inductor circuit including inductors that are connected in series; a variable capacitance circuit including variable capacitors that are connected in series, each of the variable capacitors changing a capacitance value depending on a difference in electrical potentials between both terminals of each of the variable capacitors; at least one capacitance switching circuit that includes a capacitive element and a switching element; a negative resistance circuit; and a control section that applies a power-supply voltage to a connection point between the inductors, wherein the inductor circuit, the variable capacitance circuit, the at least one capacitance switching circuit, and the negative resistance circuit are parallelly connected to each other, a control voltage is applied to a connection point between the variable capacitors and a control signal is inputted into the capacitance switching circuit, the control section changes the power-supply voltage in association with a temperature change, so as to maintain the oscillation frequency of the local oscillation signal at a constant regardless of a temperature change, and the control section includes: