Variable capacitance circuit arrangement
AssigneeIntel Corporation
InventorsColin Leslie Perry, Stephen John Parry, Alessandro F. Deidda, Christopher R. Shepherd
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Abstract
A variable capacitance network is disclosed, comprising a plurality of capacitance arms connected in parallel with each other between first and second terminals of the network. Each capacitance arm has a varactor and a series capacitor in series with the varactor A control input applies a common control signal to the junctions between the varactors and their associated series capacitors, to allow for simultaneous control of each varactor.
Claims20
A voltage-controllable oscillator comprising:
- an inductance;
- a plurality of tuning circuit arms connected in parallel with each other across the inductance, each tuning circuit arm comprising a respective varactor and an associated series capacitor having a capacitance value and being in series with that respective varactor;
- and
- control input means coupled to the junctions between the varactors and their associated series capacitors, and arranged to apply a common control signal to each varactor;
- wherein series capacitors capacitance values are weighted such that, as a control voltage is increased, tuning arms having progressively increasing fixed capacitance values are successively brought into their variable capacitive regions.
A variable capacitance network comprising:
- a plurality of capacitance arms connected in parallel with each other between first and second terminals of the network, each capacitance arm comprising a respective varactor and an associated series capacitor having a capacitance value and being in series with that varactor;
- control input means coupled to the junctions between the varactors and their associated series capacitors, and arranged to apply a control signal to each varactor;
- and
- control means having a control voltage range over which they cause the capacitance between the first and second terminals to vary;
- wherein the series capacitors and capacitance values are weighted such that, as the control voltage is increased, capacitor arms having progressively increasing series capacitance values are successively brought into their variable capacitance regions.
A tunable radio frequency (RF) circuit comprising:
- a circuit arrangement having a variable tuning capacitance including:
- a plurality of tuning varactors effectively connected in parallel and coupled to the tuning varactors;
- control means arranged to apply a control signal to each varactor for electronically controlling the capacitances of the varactors;
- and
- one or more inductors,
- wherein the control means has a control range over which the varactors cause the capacitance of the circuit arrangement to vary, and wherein the varactors each have a respective fixed capacitor connected in series having a capacitance value, the resulting series combination being coupled to the at least one inductor, the control means being coupled to the nodes between the varactors and their respective fixed capacitors, wherein the fixed capacitor capacitance values are weighted such that as the control voltage is increased, capacitance arms having progressively increasing fixed capacitance are successively brought into their variable capacitance regions.
Dependencies are inferred from the claim text.