Patent ID: 8131233

Claim:
A polar modulation transmitter, comprising: an amplitude modulation (AM) path including an amplitude modulation correction circuit configured to receive and predistort a digital amplitude component signal depending on amplitudes of samples in the digital amplitude component signal, to generate a predistorted digital amplitude component signal; a phase modulation (PM) path including a first delay element and a phase modulation correction circuit, said first delay element configured to receive and delay a digital phase component signal, to generate a delayed digital phase component signal having a delay corresponding to a latency introduced by said amplitude modulation correction circuit, and said phase modulation correction circuit configured to predistort the delayed digital phase component signal depending on amplitudes of samples in the predistorted amplitude component signal, to generate a predistorted digital phase component signal; first and second digital-to-analog converters (DACs) configured in said AM and PM paths, respectively, said first DAC configured to convert the predistorted digital amplitude component signal into a predistorted analog amplitude modulation signal, and said second DAC configured to convert the predistorted digital phase component signal into a predistorted analog phase modulation signal; an amplitude modulator configured to modulate a direct current (DC) power supply according to amplitude variations in said predistorted analog amplitude modulation signal, to produce a predistorted amplitude-modulated power supply signal; a phase modulator configured to modulate a radio frequency (RF) carrier signal according to phase variations in said predistorted analog phase modulation signal, to produce a predistorted phase-modulated RF carrier signal; an RF power amplifier (PA) having a power supply port configured to receive the predistorted amplitude-modulated power supply signal from said amplitude modulator, an RF input port configured to receive the predistorted phase-modulated RF carrier signal from said phase modulator, and an RF output port; and another delay element configured in either of said AM and PM paths operable to provide a delay that ensures that the predistorted amplitude-modulated power supply signal and the predistorted phase-modulated RF carrier signal arrive at the power supply and RF input ports of the PA in proper timed alignment.