Patent ID: 8160518
Filing Date: 2012-04-17
Classification: H04B

Abstract:
1. A circuit comprising: a power amplifier having an input terminal coupled to an output terminal of a transmitter, a control terminal, and an output terminal for providing an output signal; a harmonic termination circuit comprising an inductive element, a capacitor, and a varactor, the inductive element having a first terminal coupled to the output terminal of the power amplifier, and a second terminal; the capacitor having a first plate electrode coupled to the second terminal of the inductive element, and a second plate electrode; and the varactor having a first current electrode coupled to the second plate electrode of the capacitor, a second current electrode coupled to the power supply voltage terminal, and a control electrode; and a power amplifier control circuit having a first output terminal for providing a power control signal to the control terminal of the power amplifier, and a second output terminal for providing a tunable harmonic termination voltage to control a capacitance of the varactor, wherein the tunable harmonic termination voltage is provided at a first voltage level to cause the varactor to provide a first capacitance during a linear operating mode and the tunable harmonic termination voltage is provided at a second voltage level to cause the varactor to provide a second capacitance during a non-linear operating mode.