Patent ID: 8358170

Claim:
A system for improving linearity of a power amplifier, comprising: a first input operable to couple to an input signal path of the power amplifier for obtaining a first sample of an input signal of the power amplifier; a second input operable to couple to an output signal path of the power amplifier for obtaining a second sample of an output signal of the power amplifier, the second sample comprising at least one sampled non-linearity component corresponding to at least one non-linearity component of the output signal; an output operable to couple to the output signal path of the power amplifier for applying a linearity improving signal to the output signal path downstream from the second input; a third input operable to couple to the output signal path at a location downstream from the second input and the output for obtaining a third sample of the output signal; and a linearizer electrically coupled to the inputs and the output and comprising: a first signal canceller for deducting the first sample from the second sample to generate an intermediate signal comprising the at least one sampled non-linearity component; a second signal canceller coupled to an output of the first signal canceller and operable to produce the linearity improving signal by adjusting at least one of an amplitude, a phase, and a delay of the at least one sampled non-linearity component based on a control setting, the linearity improving signal operable to reduce an intensity of the at least one non-linearity component in response to being coupled to the output signal path at the output; a power detector for measuring an intensity level of at least one of the at least one non-linearity component of the third sample; a control device that adjusts the control setting of the second signal canceller based on the measured intensity level; and a second power detector for measuring an intensity of at least one spectral component of the intermediate signal, wherein the control device receives an intensity measurement from the second power detector and adjusts at least one setting of the first signal canceller based on the intensity measurement.