Patent ID: 6449466
Filing Date: 2002-09-10
Classification: H01Q

Abstract:
For use in an RF transmitter having a transmit path capable of receiving a digital input baseband signal and generating therefrom a modulated RF output signal, a pre-distortion correction circuit for correcting an amplification distortion caused by an RF power amplifier in said transmit path, said pre-distortion circuit comprising:input sampling means coupled to an input of said transmit path capable of capturing from said digital input baseband signal a first input sample of amplitude X; demodulation circuitry coupled to an output of said transmit path capable of receiving and demodulating said modulated RF output signal to thereby produce a digital output baseband signal; output sampling means coupled to said demodulation circuitry capable of capturing a first output sample from said digital output baseband signal corresponding to said first input sample; and processing means capable of comparing said first input sample and said first output sample and determining therefrom a pre-distortion correction value corresponding to said amplitude X, wherein said processing means is capable of determining if said amplitude X is sufficiently small to ensure that said amplification distortion caused by an RF power amplifier is negligibly small and, in response to said determination, is capable of determining a scaling factor for output samples.