AMPLIFIER APPARATUS AND METHOD

摘要

An amplifier arrangement for optimising efficiency at a peak power level and a back-off power level comprises a main power amplifier provided in a main branch for receiving a first signal, the main power amplifier being configured to operate in a class-B mode of operation. An auxiliary power amplifier is provided in an auxiliary branch for receiving a second signal, the auxiliary power amplifier being configured to operate in a class-C mode of operation. The main power amplifier and the auxiliary power amplifier are substantially matched in size. The first signal and the second signal have a phase offset value θ that is selected in relation to a particular back-off power level γ of operation, wherein 0<θ<180°. A combining network is configured to couple the output signals of the main and auxiliary amplifiers to an output node of the amplifier arrangement such that the output of the auxiliary power amplifier load modulates the output of the main power amplifier. The circuit element values of the combining network are derived based on the selected phase shift value θ and the related back-off power level γ at which the amplifier arrangement is optimised for efficiency.

主权项

1. An amplifier arrangement for optimising efficiency at a peak power level and a back-off power level, the amplifier arrangement comprising:
a main power amplifier provided in a main branch for receiving a first signal, the main power amplifier being configured to operate in a class-B mode of operation; an auxiliary power amplifier provided in an auxiliary branch for receiving a second signal, the auxiliary power amplifier being configured to operate in a class-C mode of operation; wherein the main power amplifier and the auxiliary power amplifier are substantially matched in size, and wherein the received first and second signals have a phase offset value (θ) that is selected in relation to a particular back-off power level (γ) of operation, wherein 0<θ<180°; and a combining network configured to couple the output signals of the main and auxiliary amplifiers to an output node of the amplifier arrangement such that the output of the auxiliary power amplifier load modulates the output of the main power amplifier, wherein the circuit element values of the combining network are derived based on the selected phase shift value (θ) and the related back-off power level (γ) at which the amplifier arrangement is optimised for efficiency.