Dynamic bias for a power amplifier

摘要

A dynamic bias controller dynamically biases a plurality of amplifiers residing in a power amplifier. Based upon a communication signal amplitude, the dynamic bias controller turns off (removes bias from) selected amplifiers when the communication device is to transmit a low power communication signal, and turns on (applies bias to) selected amplifiers when the communication device is to transmit a higher power communication signal. A plurality of dynamic bias controllers may control a plurality of amplifiers such that a plurality of communication signal strengths can be realized. Another embodiment employs a dynamic bias controller to control at least one prematching impedance network coupled to the selected amplifier, thereby adjusting the system impedance to a desired value.