Digital Power Encoder for Direct Digital-RF Transmitter

A transmitter, comprising:

• a first digital up-converter for converting data to an intermediate frequency (IF) signal;
• a pulse width modulator (PWM) for encoding the IF signal to an IF pulse train, wherein the PWM is a multi-level PWM, further comprising:
• a splitter for duplicating the IF signal;
• and
• two multi-level quantizers, each quantizer quantizes the IF signal based on the comparison of the IF signal with a set of thresholds to produce two waveforms, wherein the two multi-level quantizers includes a first quantizer and a second quantizer, and the set of thresholds includes a first set of thresholds and a second set of threshold, and wherein values of the threshold in the first set are opposite to values of the threshold in the second set;
• a combiner for combining the two waveforms to produce the IF pulse train;
• a second digital up-converter for converting the IF pulse train to a radio frequency (RF) pulse train;
• a power amplifier for amplifying the RF pulse train;
• and
• a filter for reconstructing a RF analog signal from the amplified RF pulse train.