Patent ID: 6657502
Filing Date: 2003-12-02
Classification: H03B

Abstract:
A voltage controlled oscillator (VCO) providing a plurality of phases of the same oscillator frequency, said VCO comprising a plurality of phase drivers each driving an oscillator phase, each phase driver being voltage controllable and receiving at least two oscillator phases,wherein said VCO is a quadrature VCO and includes two pair of cross coupled phase drivers, each of said phase drivers of each said pair receiving a phase from said other pair of cross coupled phase drivers, each received said phase being ninety degrees out-of-phase with the corresponding phase driver output, wherein each of said phase drivers comprises at least two independently controllable transconductance amplifiers, each of said controllable transconductance amplifiers receiving a control voltage and an input phase and generating an output therefrom responsive to said control voltage to said input phase, said output from both of said at least two independently controllable transconductance amplifiers being connected together and driving an oscillator phase at an output of said phase driver.