Patent ID: 6606483
Filing Date: 2003-08-12
Classification: H03F,H03G,H04B

Abstract:
A linear transmitter comprising:an amplifier feedback loop comprising: a power amplifier that receives and amplifies an input signal to produce an output signal, wherein the power amplifier comprises an input port and an output port; a feedback circuit coupled to the output port of the power amplifier that samples the output signal to produce a sampled output signal; a plurality of switching devices that couple the feedback circuit to, and decouple the feedback circuit from, the input port of the power amplifier; an auxiliary loop coupled to the amplifier feedback loop that receives the sampled output signal from the feedback loop, compares the sampled output signal to a desired input signal, determines a phase error based on the comparison of the sampled output signal to the desired input signal, and aligns a phase of the sampled output signal with a phase of the input signal based on the phase error; and wherein the power amplifier operates at a first operating point when decoupled at the input port from the feedback circuit, wherein the power amplifier operates at a second operating point when coupled at the input port to the feedback circuit, and wherein the first operating point is different than the second operating point.