High efficiency multi-band envelope tracking power amplifier with tunable output frequency bands

A multi-band power amplifier (PA) with electrically tunable output matching network is reported, whose output power and efficiency can be optimized over multiple frequencies (750MHz, 880MHz and 940MHz). It is incorporated within an envelope tracking (ET) amplifier using a high efficiency dynamic envelope voltage supply. High efficiency (50%) for all the three bands has been demonstrated with good output linearity, using a memory digital predistortion (DPD) method.