Concurrent dual-band envelope tracking power amplifier for carrier aggregated systems

This paper presents a dual-band envelope tracking power amplifier (ET PA) capable of amplifying concurrent dual-band modulated signals using a typical single-band envelope amplifier. The dual-band ET PA succeeded to concurrently amplify widely spaced dual-band modulated signals with balanced and imbalanced output powers in each band. The dual-band ET PA was linearized using dual-band Volterra based digital pre-distortion that accounted for the drain supply modulation. When driven with a dual-band signal formed of WCDMA and 5MHz LTE signals at 780MHz and 880MHz respectively, the ET PA achieved an average output power and drain efficiency of better than 39 dBm and 45% with an adjacent channel power ratio of better than -47 dBc for both bands.