A voltage controlled oscillator comprises a negative resistance, a first inductor, a fixed capacitor, and a frequency control component. The frequency control component comprises at least one varactor and at least a second inductor connected in series with the at least one varactor. A magnitude of an inductance of the second inductor is selected such that the frequency control component has an effective capacitance range larger than a capacitance range of the at least one varactor.

A voltage-controlled oscillator (VCO) having an LC tank circuit with a variable inductance is disclosed. In one embodiment, the VCO includes a capacitance, at least a portion of which is variable and responsive to a first tuning voltage. The VCO further includes a transformer having first (primary) and second (secondary) windings. The primary winding is coupled to the capacitance, and provides the inductance of the LC tank circuit. The secondary winding is coupled to a current control circuit. The current control circuit may vary the induced current through the secondary winding. By varying the induced current through the secondary winding, the effective inductance of the primary winding may also be varied. Accordingly, the VCO may be tuned by varying the inductance of the LC tank circuit, as well as by varying the capacitance of the same.

An inductor layout comprising a first inductor and a second inductor. The first and second inductors are electrically and magnetically independent inductors concentrically arranged on an integrated circuit. At least one of the first and second inductors is a multi-loop inductor with a first axis of symmetry.

A varainductor includes a signal line, a ground plane, and a floating plane over a substrate. The ground plane is disposed on a side of the signal line, and the first floating plane is disposed between the ground plane and the signal line. An array of switches includes at least two switches configured to selectively electrically connect the ground plane to the floating plane.

A voltage controlled oscillator comprises a negative resistance, a first inductor, a fixed capacitor, and a frequency control component. The frequency control component comprises at least one varactor and at least a second inductor connected in series with the at least one varactor. A magnitude of an inductance of the second inductor is selected such that the frequency control component has an effective capacitance range larger than a capacitance range of the at least one varactor.

A varainductor including a signal line disposed over a substrate. The varainductor further includes a first ground plane over the substrate, the first ground plane disposed on a first side of the signal line, and a second ground plane over the substrate, the second ground plane disposed on a second side of the signal line opposite the first side of the signal line. The varainductor further includes a first floating plane over the substrate, the first floating plane disposed between the first ground plane and the signal line, and a second floating plane over the substrate, the second floating plane disposed between the second ground plane and the signal line. The varainductor further includes an array of switches, the array of switches is configured to selectively connect the first ground plane to the first floating plane, and to selectively connect the second ground plane to the second floating plane.

A varainductor includes a spiral inductor, a ground ring, and a floating ring. The floating ring is disposed between the ground ring and the spiral inductor and surrounds a ring portion of the spiral inductor. A switching element, controlled by a switch control signal, selectively electrically connects the ground ring to the floating ring. The switching element includes one or more switches. The one or more switches are controlled by one or more signals of the switch control signal to adjust the inductance level of the varainductor.

A varainductor includes a spiral inductor, a ground ring, and a floating ring. The floating ring is disposed between the ground ring and the spiral inductor and surrounds a ring portion of the spiral inductor. A switching element, controlled by a switch control signal, selectively electrically connects the ground ring to the floating ring. The switching element includes one or more switches. The one or more switches are controlled by one or more signals of the switch control signal to adjust the inductance level of the varainductor.