Open AccessSimple and low‐cost tracking generator design in envelope tracking radio frequency power amplifier system for WCDMA applications
Author(s) -
Yusoff Zubaida,
Lees Jonathan,
Chaudhary Muhammad Akmal,
Carrubba Vincenzo,
Choi Heungjae,
Tasker Paul,
Cripps Steve C.
Publication year - 2013
Publication title -
iet microwaves, antennas and propagation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.555
H-Index - 69
eISSN - 1751-8733
pISSN - 1751-8725
DOI - 10.1049/iet-map.2013.0091
Subject(s) - amplifier , electronic engineering , rf power amplifier , radio frequency , engineering , electrical engineering , broadband , transformer , signal (programming language) , computer science , telecommunications , voltage , cmos , programming language
A simple analogue technique called auxiliary envelope tracking, or AET, is presented, which is shown to be capable of improving the efficiency of a radio frequency power amplifier (RFPA). This AET signal is an amplified envelope signal that supplies the drain port of the RFPA. The concept of AET is explained and a theoretical background for the technique is presented. The main feature of this technique lies in the separation of the DC and AC components of the tracking signal. This allows for a very simple and low‐cost tracking generator design that consists of a simple source follower amplifier and an RF broadband transformer. A practical system has been implemented and the measured results are obtained for WCDMA signals. A measurement on the realised system shows a 50% improvement in the drain efficiency at average output power of 33 dBm of a 25 W GaN. This substantial improvement is achieved at a competitive WCDMA signal with peak‐to‐average envelope power ratio of 9.17 dB.