Holistic Design of Power Amplifiers for Future Wireless Systems

功率放大器是所有现代无线通信系统的主要基本组成部分之一。它们被用于目前可用的所有基站和所有移动设备。为了维持所需的系统性能水平，目前市售的放大器被设计成以极低的效率水平运行，这意味着它们消耗的能量远远超过严格必要的能量。例如，目前英国的基站以大约12%的效率水平运行，这导致每年向大气中排放超过609,000吨的二氧化碳。如果这些基站的效率达到50%，二氧化碳排放量每年可以减少45万吨以上。高效率、高线性功率放大器的设计是一个极其复杂的过程。目前，高线性放大器的设计是使用基于试错的方法进行的，其中设计是起草的，然后制作原型并确定设计问题。整个过程不断重复，直到找到最佳解决方案。这导致制造商采取非常危险的不利方法放大器设计，导致非常低效的系统。越来越需要开发具有更高数字数据吞吐量的无线通信系统。例如，近年来我们看到了第三代3G移动通信系统的推出以及无线局域网系统的日益普及。未来所谓的第4代系统很有可能包含同样使用无线局域网技术的调制方案。随着3G系统的引入，很明显，现有的设计方法用于放大器的开发和优化是劳动密集型和耗时的。目前的方法已经成为现代通信系统评估、开发和测试的主要障碍。本提案旨在克服这些基本的设计问题，通过建立一个科学健全的非线性电路的完全互连的设计方法。通过结合布里斯托尔的世界级功率放大器设计专业知识和波形测量/工程专业知识/在卡迪夫引入和开创/将建立科学可靠的非线性设计方法，其中测量的波形和波形工程将促进放大器设计和线性化的新方法。其目的是为未来的通信系统设计一个单通过程，这将导致在商业环境中利用这项技术。

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.