RADIO FREQUENCY COMPOSITE CLASS-S POWER AMPLIFIER HAVING DISCRETE POWER CONTROL

摘要

A composite amplifier providing digitally selectable amplification includes a plurality of channels and a combiner. Each of the channels includes a digitally controllable selector, a Class-S power amplifier, and bandpass filter. The digitally controllable selector selectively couples a digital bitstream to the amplifier. The amplifier receives the digital bitstream and provides an amplified signal. The bandpass filter generates a filtered signal as a function of the amplified signal. The combiner couples filtered signals provided by the channels to form a composite output signal. A method of providing digitally selectable amplification includes steps of: selectively coupling a digital bitstream to a plurality of channels in the amplifier; amplifying the digital bitstream to provide an amplified signal associated with a corresponding one of the channels; filtering amplified signals associated with the channels to provide corresponding filtered signals; and combining the filtered signals to generate a composite output signal.