Low-noise tunable capacitor and method thereof

Abstract

A method of capacitance tuning operates by disposing an AC (alternating current) coupling capacitor between a first node and a second node; disposing a varactor between the second node and a third node; disposing a diode-based DC (direct current) coupling network comprising a series connection of a resistor and a diode between the second node and a fourth node, wherein an impedance of the resistor is substantially greater than an impedance of the varactor at a frequency of interest; applying a control voltage that is subject to dynamic variation to the third node; and applying a bias voltage that is substantially static to the fourth node.

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