A Mirror Predistortion linear power amplifier

We propose a new type of predistortion linearization technique: “Mirror Predistortion”. In a regular predistortion power amplifier (PA), the AM-AM and AM-PM distortion (Or IMD3, Third Order Inter-modulation Distortion, and IMD5) of the PA are not known before measurement. In the Mirror Predistortion technique, we choose a PA with identical design as, but smaller than the main PA, as a Mirror Predistorter (PD). Since this Mirror PD´s nonlinear characteristics tracks the main PA, there is no need for nonlinear characterization for the PD or the PA. We have reduced this concept to practice and have built a mirror predistortion linear PA having 23 dB improvement in IMD3, at a 2-tone total output power of 34 dBm, with 7.5 dB back off from P1dB of 41.5dBm.