Patent ID: 7583156

Claim:
An oscillator with extended frequency tuning range, the oscillator comprising a plurality of inductor-capacitor (LC) tanks, the plurality of LC tanks comprising: A. a multi-tap inductor having at least two pairs of taps and a center tap, wherein each pair of taps is coupled to a conductor at specified positions on the conductor, wherein the center tap is coupled to a first power rail; B. a plurality of capacitors, each capacitor having a first terminal coupled to a tap of the pairs of taps of the multi-tap inductor; C. a plurality of negative-Gm stages, each negative-Gm stage controllably coupled to a pair of taps of the multi-tap; and D. each capacitor in the plurality of capacitors has a second terminal coupled to a voltage reference, and wherein the voltage reference comprises a second power rail, an AC ground, or a virtual ground.