Analysis of the integration of envelope tracking with Continuous Class F amplifiers

This paper analyses the suitability of Continuous Class F power amplifiers (PA) for use with envelope tracking (ET) systems. The effect on PA performance of reducing the drain bias is examined. The ET detroughing function is optimised in order to maximise the system linearity. When excited with 5 MHz WCDMA and 20 MHz LTE signals, the ET amplifier was found to improve PAE and ACPR by 18% and 11 dB, respectively, for the WCDMA case, and by 21% and 5 dB respectively, for the LTE case, when compared with a Continuous Class F amplifier without envelope tracking.