POWER CONTROL OF SWITCHED-MODE POWER AMPLIFIERS WITH ONE OR MORE STAGES

摘要

This invention controls and modulates switched-mode power amplifiers to enable the production of signals that include amplitude modulation and possibly, but not necessarily, phase modulation, the average power of which may be controlled over a potentially wide range. The signal applied to the power supply port of the amplifier 1211,1201 is varied to control the modulation characteristics of the amplifier output signal. A final amplification stage 1201 is repeatedly driven by a drive signal between hard-on and hard-off states, without operating in a linear operating region for a specific period. The amplification stage 1211,1201 is controlled without continuous frequent measurement and feedback adjustement of variable output signal of amplifier.