Patent ID: 7705675
Filing Date: 2010-04-27
Classification: H03F,H04B

Abstract:
1. A circuit for amplifying an RF signal, the circuit comprising: a push-pull amplifier comprising a push transistor and a pull transistor; a first driver amplifier that drives the push transistor of the push-pull amplifier with a first RF signal; and a second driver amplifier that drives the pull transistor of the push-pull amplifier with a second RF signal different from the first RF signal; wherein the push-pull amplifier is a first push-pull amplifier, and wherein the first driver amplifier comprises a second push-pull amplifier and the second driver amplifier comprises a third push-pull amplifier; wherein the first and second driver amplifiers each comprise a tuned class D amplifier; wherein the circuit further comprises: a first load network coupled to the first driver amplifier, the first load network having an impedance selected such that the first driver amplifier operates in a class DE mode; a second load network coupled to the second driver amplifier, the second load network having an impedance selected such that the second driver amplifier operates in a class DE mode; and a third load network coupled to the first push-pull amplifier, the third load network having an impedance selected such that the first push-pull amplifier operates in a class DE mode.