Fully Digital Adaptive Control of a Feed-Forward Amplifier Implemented with Digital Signal Processor

A complete digital adaptive control is introduced for the mulling and the error loop of a 1.96 GHz feed-forward linearization system. The nulling loop is controlled with a well known power gradient method and the error loop is controlled with a frequency domain cancellation method using a Digital Signal Processor (DSP). To our knowledge it is the First time that experimentals results show 20 dB improvement on the inter-modulations product regardless of the input power level