Holistic Design of Power Amplifiers for Future Wireless Systems
Lead Research Organisation:
University of Bristol
Department Name: Electrical and Electronic Engineering
Abstract
Power amplifiers are one of the main fundamental building blocks of all modern wireless communications systems. They are used in all base stations and all the mobile units which are currently available. To maintain the required levels of system performance current commercially available amplifiers are designed to operate with extremely poor levels of efficiency which means they consume far more energy than is strictly necessary. For example current base stations in the UK operate at an efficiency level of approximately 12% this results in over 609,000 of CO2 emissions into the atmosphere on an annual basis. If these base stations were to be 50% efficient CO2 emissions could be cut by over 450,000 tons per year. The design of highly efficient and highly linear power amplifiers is an extremely complex process. At present the design of highly linear amplifiers is carried out using a trial-and-error based approach where designs are drawn up, then a prototype is produced and design issues are identified. The whole process is repeated until an optimum solution is reached. This has lead manufacturers to take a very risk adverse approach to amplifier design which has resulted in very inefficient systems. There is an increasing need to develop wireless communications systems with increased digital data throughput. For example, in recent years we have seen the roll out of 3rd generation 3G mobile communication systems and the increasing use of wireless LAN systems. It is highly likely that the future so-called 4th generation systems will contain modulation schemes which also use wireless LAN technology. With the introduction of 3G systems it became clear that the existing design methodologies for the development and optimisation of amplifiers are labour intensive and time consuming. The present approach has become a key hindrance in the evaluation, development, and testing of modern communication systems. This proposal seeks to overcome these fundamental design issues through the establishment of a scientifically robust fully interlinked design methodology for nonlinear circuits. By combining the world-class power amplifier design expertise in Bristol and waveform measurement/engineering expertise /introduced and pioneered in Cardiff/ a scientifically robust nonlinear design methodology will be established in which the measured waveforms and waveform engineering will facilitate new methods of amplifier design and linearisation. The aim being a one pass design process for future communications systems which will result in the exploitation of this technology within a commercial setting.
Publications
Hone T
(2012)
Controlling Active Load-Pull in a Dual-Input Inverse Load Modulated Doherty Architecture
in IEEE Transactions on Microwave Theory and Techniques
Souheil Bensmida (Co-Author)
(2012)
Nonlinear Envelope Tracking for Efficiency Optimization of Power Amplifiers
Souheil Bensmida (Co-Author)
(2010)
Generic Pre-distortion of a Class-J Power Amplifier
Mohamad Akmal (Co-Author)
(2012)
Characterization of Electrical Memory Effects for Complex Multi-tone Excitations using Broadband Active Baseband Load-pull
Muhamad Akmal (Co-Author)
(2010)
Minimization of Baseband Electrical Memory Effects in GaN HEMTs Using Active IF Load-pull
Thomas Hone (Co-Author)
(2011)
Optimized Load Modulation in a Doherty Amplifier using the Current Injection Technique
Muhamad Akmal (Co-Author)
(2011)
An Enhanced Modulated Waveform Measurement System for the Robust Characterization of Microwave Devices under Modulated Excitation
Description | The project has resulted in a breakthrough in the design of signal amplifiers for mobile phone masts which could deliver a massive 200MW cut in the load on UK power stations, reducing CO2 emissions by around 0.5 million tonnes a year. The amplifier designed in the project works at 50 per cent efficiency compared with the 30 per cent now typically achieved. Currently, a 40W transmitter in a phone mast's base station requires just over 130W of power to amplify signals and send them wirelessly to people's mobiles. The new design, however, enables the transmitter to work effectively while using just 80W of power. If 10,000 base stations in the UK were fitted with the new amplifier, it is estimated that the total saving would amount to half the output of a mid-size, 400MW power station. There are currently around 50,000 phone mast base stations in the UK, so the potential energy and carbon-saving benefits could be even greater. The development of a less power-hungry amplifier has focused on devising sophisticated new computing algorithms for incorporation into its inbuilt electronic management system, as well as on making a number of adjustments to the amplifier hardware. The project has also succeeded in simplifying the whole amplifier design process, which is of vital importance to encouraging widespread take-up of the project's findings. Traditionally, designing signal amplifiers for base stations has been a long, complex process involving a trial-and-error approach and producing one-off solutions. This has fuelled a reluctance to develop new amplifier designs. To get over that barrier, the project made it a priority to ensure the design is easily replicable. |
Exploitation Route | The work carried out in this project has formed part of an impact acceleration award with a well known mobile phone handset manufacturer. They are now investigating how this work may be implemented in the next generation of their products |
Sectors | Digital/Communication/Information Technologies (including Software),Electronics |
URL | http://www.bristol.ac.uk/news/2014/april/signal-amplifiers.html |
Description | This work has contributed to a number of industry focused activities and also informed industrial practice |
First Year Of Impact | 2012 |
Sector | Digital/Communication/Information Technologies (including Software) |
Description | Sony Power Amplifier Characterisation |
Organisation | SONY |
Department | Sony Broadcast and Professional Europe |
Country | United Kingdom |
Sector | Private |
PI Contribution | We meet staff from Sony Europe at a Cambridge Wireless event where we were displaying the results of the project. We have characterised an amplifier that they had design and also investigated methods of linearistion. |
Collaborator Contribution | Sony provided the amplifier modules using a new design process they had developed. They have also made use of the results to inform design decisions taken in developing their products in this area. |
Impact | Conference Paper S. Bensmida, K. A. Morris, J.C. Clifton and A. Lawrenson, Advanced GaAs Power Amplifier Architecture Linearized with a Post distortion method, IEEE International Microwave Symposium 2014 (IMS 2014), Tampa Florida USA, June 2014. Journal Paper Lutfi Albasha, Chris Clifton, Yoshikatsu Jingu, Alan Lawrenson, Hideshi, Motoyama, Souheil Bensmida, Kevin A. Morris and Kazumasa Kohama "An Ultra-Wideband Digitally Programmable Power Amplifier with Efficiency Enhancement for Cellular and Emerging Wireless Communication Standards" for publication in the IEEE Transactions on Circuits and Systems I: Regular Papers, Vol 63, Issue, 10, Pages 1579-1590. October 2016. |
Start Year | 2013 |
Description | Demonstration of Amplifier technology EuMC 2012 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Participants in your research or patient groups |
Results and Impact | Demonstration of Amplifier technology at the European Microwave conference Exhibition October 2012 Amsterdam. |
Year(s) Of Engagement Activity | 2012 |
Description | Holistic Design of Power Amplifiers for Future Wireless Systems Exhibition of outcomes at IEEE 41st European Microwave Conference 2011 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | |
Results and Impact | Display containing demonstrator showing key outcomes at IEEE 41st European Microwave Conference 2011 Manchester October 2011. |
Year(s) Of Engagement Activity | 2011 |
Description | Royal Academy of Engineering Summer Exhibition May 2012 |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Primary Audience | |
Results and Impact | Invited demonstration of amplifier technology at the Royal Academy of Engineering Summer Soirée held in Cardiff University in May 2012 in the presence of Her Royal Highness Princes Anne. |
Year(s) Of Engagement Activity | 2012 |