HIGH-FREQUENCY DRAIN POWER SUPPLY TO DECREASE POWER DISSIPATION IN CLASS-AB POWER AMPLIFIERS

摘要

The present invention relates to the control of power amplifiers in order to enhance the efficiency of the amplifier by tracking the envelope of input signal and applying the same envelope into the drain voltage of a last stage power transistor. This invention can be used in each and every wireless communication transmitter, since there is definitely a power amplifier in the last part of the transmitter before the antenna, and every power amplifier has limited power performance, depending on type of modulation, due to its input-output curve. We are aiming to enhance the power utility of power amplifiers in different applications through introducing a new method and circuit for supplying power into a power amplifier, wherein the power supplied to the drain of the power amplifier is made to follow the envelope of the transmitted RF signal. Embodiments of the invention provide for a drain power supply module to drive the drain of a power amplifier, wherein an array of parallel amplifiers is controlled, depending on the envelope, to switch at different phases.

主权项

1. A method for supplying a modulated power signal to a power amplifier, the method comprising:
receiving an envelope signal based on a modulation of an input signal used to drive the power amplifier; driving an array of at least two amplifying elements, the amplifying elements being connected in parallel such that they each are supplied by a substantially constant DC power supply, each amplifying element being driven during at least one phase, the at least one phase being independent of any other amplifying element, the at least one phase being based on the envelope signal and a feedback signal based on at least part of the modulated power signal.