Method and apparatus for tuning frequency of LC-oscillators based on phase-tuning technique

A tunable multiphase ring oscillator includes a plurality of stages connected in series in a ring structure, where each stage generating a stage output from a stage input. Each stage of the tunable multiphase ring oscillator includes a plurality of trans-conductance cells, each generating an output from at least one portion of the stage input. Each stage further includes at least one phase shifting module for imparting at least one phase shift to the at least one portion of the stage input, an oscillator unit for generating the stage output from a combination of the plurality of outputs, and means for varying at least one of the plurality outputs so as to adjust a phase of the stage output.