Wideband Digital Intensive Doherty Concepts

Master thesis (2021)

Authors

Faustas Bagdonas Electrical Engineering, Mathematics and Computer Science

Contributors

L.C.N. de Vreede Electronics - EEMCS (supervisor 1)
R.J. Bootsman Electronics - EEMCS (supervisor 2)
John Gajadharsing Ampleon (coach)
Faculty
Electrical Engineering, Mathematics and Computer Science
Copyright: © 2021 Faustas Bagdonas
Transmitter RF power amplifier Wideband Doherty Pseudo Doherty Load Modulated Balanced Amplifier DTX
More Info
expand_more

Published Date

18-11-2021

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Electrical Engineering, Mathematics and Computer Science

Abstract

Many applications require wide bandwidth transmitters, but unfortunately, they usually have way less than 50% average drain efficiency for their modulated signals. This low efficiency is a significant drawback in all wireless applications, both for battery power devices and base stations. The Doherty radio frequency (RF) power amplifier architecture is widely used to enhance the average efficiency for modulated signals in base stations. Its popularity is due to its relatively cheap and simple hardware and its suitability to handle high-power wideband modulated signals. However, even Doherty amplifiers often have less than 50% average efficiency and are restricted in their RF bandwidth.
This thesis reviews recent research on the Doherty power amplifier (DPA) topology and discusses possible power and bandwidth efficiency improvements. In the second part of the thesis, another topology is introduced, which also provides Doherty-like behavior. That topology is called a Pseudo Doherty Load Modulated Balanced Amplifier (PD-LMBA). The performance of PD-LMBA is compared with “conventional” DPAs. Circuit design examples of DPA and PD-LMBA are given. The thesis concludes with a PD-LMBA prototype design, which appears to be very promising in its wideband performance.