Differential power amplifier

Abstract

A differential power amplifier is disclosed. The differential power amplifier includes an output transformer having a primary winding with a first primary terminal, a center-tap terminal, and a second primary terminal. The differential power amplifier further includes a positive amplifier having a first signal output terminal coupled to the first primary terminal and a negative amplifier having a second signal output terminal coupled to the second primary terminal. A harmonic tuning network is made up of a common-mode inductor coupled between the center-tap terminal and a tuning node and a first electronically tunable capacitor coupled between the tuning node and a fixed voltage node. A controller is configured to tune the electronically tunable capacitor to resonate with the common-mode inductor at a second harmonic frequency of a signal being amplified by the positive amplifier and the negative amplifier.

Dependencies are inferred from the claim text.