Patent ID: 6681101
Filing Date: 2004-01-20
Classification: H03C,H03F,H03G,H04B

Abstract:
A radio frequency (RF) transmitter for use in transmitting nonconstant-envelope signals, comprising:a signal processing block responsive to an input signal: a supply modulator responsive to an envelope output of the signal processing block; an FM modulator responsive to a phase output of the signal processing block; a power amplifier circuit having a plurality of amplifier stages each coupled to the supply modulator, and a plurality of switches configured to bypass selected amplifier stages, and an envelope modulator coupled between the envelope output and the supply modulator, wherein the supply modulator comprises: a multiplexer configured to receive a signal from the envelope modulator; plurality of delay lines connected to the multiplexer and to associated ones of the switches of the amplifiers; and a plurality of filters connected to corresponding ones of the switches and the drain input terminals, wherein a modulated signal is delivered to selected ones of the amplifiers.