Patent ID: 7801244

Claim:
A transmitter comprising: a polar converter adapted to convert a signal to a phase signal and an amplitude signal; a first compensator adapted to receive the amplitude signal and distort the amplitude signal such that a first compensation signal is generated; a first combiner adapted to combine the first compensation signal with the amplitude signal to create a power supply input signal; a second compensator adapted to receive the amplitude signal and distort the amplitude signal, such that a second compensation signal is generated; a second combiner adapted to combine the second compensation signal with the phase signal to produce a combined signal; a converter adapted to convert the combined signal to a frequency signal; and an amplifier adapted to receive the power supply input 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 at least partially canceled by the first compensation signal and the second compensation signal, said second compensation signal generated with a piecewise 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 two 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.