Abstract: A transmitter for directly modulating an RF carrier with a complex baseband waveform comprises a programmable device adapted to generate amplitude and phase information collectively corresponding to a complex baseband waveform, a signal generator adapted to generate an RF carrier whose phase is responsive to phase information generated by the programmable device, a plurality of delta modulators, and an amplifier coupled to the signal generator and receiving the RF carrier with phase information. Each delta modulator is operative to sample an error signal at a time period offset from all other delta modulators to thereby generate streams of pulses collectively approximating the amplitude information. The supply voltage of the amplifier is adjusted in accordance with approximated amplitude information represented by the streams of pulses generated by the delta modulators.

Abstract: Apparatus, methods and articles of manufacture for multiband transmitter power amplification are provided wherein one or more amplifying devices, of which at least one may be one or more current sources, have impedances matched for different input and output frequencies by way of various impedance matching circuits.