Patent ID: 8067995

Claim:
A voltage controlled oscillator comprising: an inductor circuit including an inductor; a plurality of variable capacitance circuits, each of the plurality of variable capacitance circuits including a variable capacitance element; at least one capacitance switch circuit; a negative resistance circuit; and a frequency sensitivity controller configured to apply various combinations of a control voltage and a plurality of control signals to the plurality of variable capacitance circuits and the at least one capacitance switch circuit, wherein: the inductor circuit, the plurality of variable capacitance circuits, the at least one capacitance switch circuit, and the negative resistance circuit are connected in parallel; the frequency sensitivity controller: is connected to a respective virtual ground point for differential signals of each of the plurality of variable capacitance circuits; fixedly applies the control voltage for feedback control of an oscillation frequency, to one variable capacitance circuit of the plurality of variable capacitance circuits; and applies one of (i) the control voltage and (ii) one control signal of the plurality of control signals, to another variable capacitance circuit of the plurality of variable capacitance circuits, based on another control signal, of the plurality of control signals, applied to the at least one capacitance switch circuit; and when the one control signal of the plurality of control signals is applied to the another variable capacitance circuit of the plurality of variable capacitance circuits, the one control signal is capable of varying between at least two voltage levels.