Patent ID: 7991071
Filing Date: 2011-08-02
Classification: H04L

Abstract:
1. A transmitter comprising: a polar converter adapted to convert a signal to a phase signal and an amplitude signal; a compensator adapted to receive the amplitude signal and distort the amplitude signal such that a compensation signal is generated; a combiner adapted to combine the compensation signal with the phase signal and produce a combined signal; a converter adapted to convert the combined signal to a frequency signal; and an amplifier adapted to receive the amplitude signal and a signal based on the frequency signal and generate an output signal, wherein distortion of the output signal caused by the amplitude signal is canceled by the compensation signal; and said compensation signal generated with a function associated with a plurality of different power levels within an overall operating range of the amplifier, such that each piece of the piecewise function is based on a corresponding set of at least three coefficients, which are based on a function that substantially matches an inverse of the phase signal over a corresponding one of the plurality of different power levels, and transitioning between two pieces of the piecewise function causes a frequency jump of the frequency signal to at least partially compensate for a phase shift in the power amplifier resulting from transitioning between two of the plurality of different power levels corresponding to the two pieces of the piecewise function.