Patent ID: 7342464

Claim:
An oscillator comprising: a variable inductor unit comprising a first inductor, a current signal generator operable to detect an electric signal denoting current flowing to the first inductor or the voltage at both ends of the first inductor, and to generate a current signal based on the electric signal, and a second inductor that receives the current signal, wherein the first inductor and second inductor are disposed to a predetermined magnetically coupled position, and the inductance of the first inductor is set desirably; a variable capacitance device connected to the variable inductor unit; an output unit that comprises one or more active elements, oscillates at an oscillation frequency determined by the inductance of the variable inductor unit and the capacitance of the variable capacitance device, and generates a VCO signal; and a control signal generator operable to generate a frequency control signal to modulate the oscillation frequency; wherein the current signal generator controls the amplitude of the current signal based on the frequency control signal.