Nowadays, it is unquestionable that communication systems play a very important role in our daily routine. Wireless systems, in particular, are growing in such a way that people have difficulty living without the services already available. This being the case, any big change, or improvement, in terms of power consumption in these systems will certainly have a big impact on what the available resources usage is concerned. Moreover, it is not acceptable that technology uses more and more resources in an unthinkable way without trying to be as efficient as possible. This project comes exactly in this direction as it tries to push further state-of-the-art systems that, unfortunately, have their own problems inherent to their infancy.
Having that in mind, this project is focused on the design and implementation of a memory-free wireless transmitter built with GaN transistors. It is undeniable that this technology was a breakthrough in what efficient and available power are concerned. Unfortunately, it still suffers from several problems that are yet to be solved. Therefore, the above referred main objective of this project can be tackled according to the following different, but interrelated, goals:
(i) It is recognized that, for understanding something in nature, first we need to carefully characterize it. In what memory-effects in GaN transistors are concerned the methodology has to be the same. So, the objective is to fully characterize them using a set of reference measurements such as: - static and dynamic AM/AM and AM/PM amplitude sweeps; - step-up and step-down output power and phase measurements going from small- into large-signal regimes; - S-parameters for the bias circuitry and matching networks characterization.
(ii) Modeling memory-effects in commercial computer added design simulators making it possible to replicate, in a virtual environment, the real operation of the device and search, in a more flexible way, for the necessary solutions.
(iii) Correct the memory-effects (short- and long-term) visible in todays’ power amplifiers and prove it with a complete prototype implementation.
|Start Date: 01-02-2014|
|End Date: 01-07-2015|
|Team: Pedro Miguel da Silva Cabral, Luis Nunes|
|Groups: Wireless Circuits – Av|
|Local Coordinator: Pedro Miguel da Silva Cabral|