Active cancellation of switching noise for DC-DC converter-driven RF power amplifiers

The use of DC-DC converters to dynamically vary the supply voltage for RF power amplifiers in accordance with the transmitted power is an increasingly popular technique that can significantly improve the efficiency. However the DC-DC converter ripple noise may degrade the power amplifier output signals. In this paper, we demonstrate an active cancellation technique that can dramatically reduce the noise. The technique can be easily integrated into present systems employing DSP and DC-DC converters.