Patent ID: 8362809

Claim:
A dual-mode voltage-controlled oscillator, characterized by comprising a first voltage-controlled oscillator unit and a second voltage-controlled oscillator unit, the first voltage-controlled oscillator unit operating in a first frequency band, the second voltage-controlled oscillator unit operating in a second frequency band, the first frequency band and the second frequency band having an overlapped frequency band therebetween; each of the voltage-controlled oscillator units comprises a quadrature coupling module; the dual-mode voltage-controlled oscillator is operable to operate in a wideband mode or a quadrature mode; wherein, when operating in the wideband mode, a differential signal at a corresponding frequency is generated by only the first voltage-controlled oscillator unit or the second voltage-controlled oscillator unit; when operating in the quadrature mode, both the first voltage-controlled oscillator unit and the second voltage-controlled oscillator unit operates in the overlapped frequency band, the first voltage-controlled oscillator unit and the second voltage-controlled oscillator unit are coupled together by the quadrature coupling modules of the first voltage-controlled oscillator unit and the second voltage-controlled oscillator unit, and a quadrature signal at a corresponding frequency is generated.