Patent ID: 8294528

Claim:
An oscillator comprising: a transformer-based LC resonator that has an odd resonant mode and an even resonant mode, wherein the transformer-based LC resonator comprises a first inductor, a second inductor, a first capacitor, a second capacitor, a third capacitor, and a fourth capacitor, wherein the first inductor and the first capacitor are coupled in parallel between a first node and a second node, wherein the second inductor and the second capacitor are coupled in parallel between a third node and a fourth node, wherein the third capacitor is coupled between the first node and the third node, wherein the fourth capacitor is coupled between the second node and the fourth node, and wherein the first and second inductors have a mutual inductance M and form a transformer; a control signal input conductor; and an active transconductance network coupled to the first, second, third and fourth nodes of the transformer-based LC resonator, wherein when a control signal on the control signal input conductor has a first digital logic value then the active transconductance network causes the transformer-based LC resonator to resonate in its odd resonant mode, and wherein when the control signal on the control signal input conductor has a second digital logic value then the active transconductance network causes the transformer-based LC resonator to resonate in its even resonant mode.