Efficiency Enhancement of A Broadband Sequential Power Amplifier Using Envelope Tracking

This paper demonstrates the first realisation of a sequential power amplifier (SPA) with envelope tracking (ET). Composed of a 10 W main PA and a 23 W peaking PA, the 1.6–2.4 GHz SPA achieves more than 49% drain efficiency at 6 dB back-off across the band through modulating the main PA supply voltage. At 2 GHz, the ET SPA offers more than 45% efficiency at 10 dB back off. Moreover, the linearity of the ET SPA is measured with and without digital predistortion over the band. To the best of the authors’ knowledge, this work is the first investigation where ET has been applied to the SPA.