Patent ID: 7646264

Claim:
An anti-parallel variable-capacitor (varactor) circuit comprising: a first varactor bank comprising one or more varactors connected in parallel with the same polarity orientation; a second varactor bank comprising one or more varactors connected in parallel with the same polarity orientation; a first capacitor pair comprising the first varactor bank connected in series with a first fixed capacitor; a second capacitor pair comprising the second varactor bank connected in series with a second fixed capacitor; said first capacitor pair connected in anti-parallel with said second capacitor pair, said varactor banks having mutually opposite polarity orientations relative to signal flow direction; circuitry for tuning said first and second varactors; an input terminal coupled to one side of said parallel connection of said first and second capacitor pairs; and an output terminal coupled to the other side of said parallel connection of said first and second capacitor pairs, a circuit including at least one varactor operatively connected in parallel to said first varactor bank by electronically controlled switching; and a circuit including at least one varactor connected in parallel to said second varactor bank by electronically controlled switching.