Supply Modulation Behavior of a Doherty Power Amplifier

Asymmetric Doherty Power Amplifier with Input Phase/Power Adjustment and Envelope Tracking

“…Envelop tracking (ET) is also developed for main or auxiliary PA in order to significantly improve the efficiency during the wide input power range [33,34]. The turn-on time of the auxiliary amplifier can be controlled by the gate bias variation as well, which always cooperates with the power ratio adjustment method [35][36][37].…”

“…Envelop tracking (ET) is also developed for main or auxiliary PA in order to significantly improve the efficiency during the wide input power range [33,34]. The turn-on time of the auxiliary amplifier can be controlled by the gate bias variation as well, which always cooperates with the power ratio adjustment method [35][36][37]. To mainly address the issue of the efficiency enhancement in the wide power dynamic range, we experimentally demonstrate an asymmetrical DPA with ET of the auxiliary amplifier in this paper, in order to keep a high efficiency over a wider range of output powers compared to classical Doherty designs.…”

Design of a Wideband Doherty Power Amplifier with High Efficiency for 5G Application

“…In order to increase back-off efficiency, various techniques have been proposed, both at the PA and at the system level, such as the Doherty power amplifier [13,15] and the Chireix outphasing [16,17] PA, based on the load modulation concept [18], or Envelope Elimination and Restoration (EER) [19,20] and Envelope Tracking (ET) [21,22] techniques, based instead on supply modulation. A combination of both supply and load modulation can be also exploited to maximize the achievable back-off efficiency [23,24]. Among all these techniques, however, the Doherty Power Amplifier (DPA) gained the highest popularity thanks to its architecture simplicity and relatively good linearity [25,26].…”