Systems and methods are provided for generating a modulated radio frequency (RF) output signal representing a baseband input signal. A digitizer is configured to sample the baseband input signal and produce an N-bit binary digital signal representing a scaled linear function of the signal amplitude. An RF signal source configured to produce an RF carrier signal. N amplifier paths each include at least one amplifier configured to receive the RF carrier signal as an input and provide a corresponding output RF signal. The amplifiers associated with each of the N amplifier paths are active only when a corresponding bit of the digital signal assumes a first value. A power combiner assembly is configured to combine the outputs of the plurality of amplifier paths to deliver the modulated RF output signal.