Abstract: Disclosed are methods, circuits and systems for modulating supply voltage to a power amplifier. An input voltage signal may be received and used to drive a switching regulator (or the like), which regulator may be adapted to modulate (convert) battery supply voltage into a supply voltage of an amplifier. An output signal combining stage may include a signal combiner which may be adapted to combine a modulated battery supply voltage (i.e. modulated by the input voltage) with a residual error correction signal (RECS). The residual error correction signal may be based on an estimate of the switching regulator characteristics. The estimate may be at least partially based on feedback from an output of the regulator. The estimate may be at least partially based on a prediction model of the switch regulator.