Today's portable microelectronic systems, such as mobile telephones, require high energy efficiencies to further battery life. They also require compact electronics. Combining these two requirements poses a problem with relation to their power supplies, since it implies greater miniaturisation, high conversion efficiencies and high power densities. Using silicon-based DC/DC converters places limits on how far these improvements can go. We intend to make use of a new gallium-nitride transistor technology to develop smaller, more efficient power supplies. Specifically, we will produce a 10W power supply in this new technology, with a high voltage conversion factor, and integrate it inside a contemporary microelectronics package. The only way that this will work is to operate the new power supply at incredibly high switching frequencies (>100 MHz), which is 10-100 times faster than today's power supplies. The project then revolves around solving the challenges of: 1) how to operate such a power supply at very high frequencies; 2) how to integrate it into a small, modern, microelectronics package. We expect key challenges to be the creation of unacceptable electromagnetic emissions from the high switching speeds, and the need to accurately control the impedances of the circuit, since circuit impedances become more significant the faster one switches. We will solve the challenges by deploying an advanced version of a drive-pulse shaping technique that we call "pulse quietening", and by using modern integration techniques, including the creation of a custom chip to control the new power supply. Our method is to create several prototypes, running at increasingly high speeds, from 1MHz up to 100 MHz. We will create models and theories about the most efficient way to drive the power supply transistors and measure the outputs, as well as furthering our knowledge and application of pulse quietening.

With the emerging automated tasks in vehicle domain, the development of in-vehicle communications is increasingly important and subjected to new applications. Although both wired and wireless communications have been largely used for supporting diverse applications, most of in-vehicle applications with mission-critical nature, such as brake and engine controls, still prefer dedicated wired networks for reliable and secure transmission. One of the key challenges for data wiring is to facilitate the interconnectivity of increasing devices, e.g., sensors and electronic control units (ECU), effectively creating an in-vehicle network with low response latency, improved reliability and less complexity. The space requirement, weight, and installation costs for these wires can become significant, especially in future vehicles, which are highly sophisticated electronic systems. Given that vehicle components, sensors and ECUs are already connected to power wires, we apply vehicle power lines, which have recently been utilized for in-vehicle communications at the physical layer, to in-vehicle networks in this proposal. Taking mass air flow sensor as an example, it has one power wire and two signal wires, it will be efficient to use power line communications to replace the current signal wires, so 66% of wiring can be reduced. The advancement of vehicular power line communications (VPLC) can provide a very low complexity and free platform for in-vehicle networks, which is ideal for the increasing demand of applications in particular with future vehicles. However, the emerging VPLC is constrained by lack of protocol support, which pose significant challenges to deploy it in practise and ensure mission-critical communications. The following example illustrates the motivation of this proposal. An example for the motivation: A future vehicle is equipped with advanced driver assistance systems (ADAS) which can be connected with multiple sensors and ECUs to provide safety monitoring and control. An important demand of this scenario is that the systems, viewed as sources, should have stable connections with all ECUs, or network destinations. And it is also important that such in-vehicle networks must guarantee ultra-low latency for emerging control services since any seconds of delay may cause fatal accident. Therefore, an effective protocol design is crucial for VPLC to support future applications with mission-critical and high-bandwidth demands. The aim of the project is to improve the reliability of the network and guarantee stringent mission-critical requirements of in-vehicle applications in vehicular power line communications. We will partner with automotive specialists and construct the project to develop innovative and intelligent in-vehicle communication protocols. The solution this proposal is seeking is two fold. One is to pursue new design of intelligent access and congestion control solutions by fully exploring the practical and theoretical analysis, dynamic nature of channels/traffic patterns and self-learning techniques, which provides the theoretic aspect of the proposal. Then, the second step is from the practical aspect, where the proposed power line method shall be able to coexist and cooperate with existing state-of-the-art solutions, and its performance will be validated by practical in-vehicle traffic data. Obviously the two are inseparable not just because the ultimate goal of reliable communication for in-vehicle networks is only possible with the accomplishment of the both two parts, but also because the interaction between the two parts is the key for effective system design.

AlGaN/GaN high electron mobility transistors (HEMT) are a key enabling technology for future power conditioning applications in the low carbon economy, and for high efficiency military and civilian, microwave and RF systems. Although the performance of AlGaN/GaN HEMTs presently reaches RF powers up to 40W/mm, at frequencies exceeding 300 GHz, their long-term reliability, often thermally limited, is still a serious issue, in the UK & Europe, but also in the USA & Japan. Corresponding challenges exist for power conditioning applications. To mitigate the present thermal device challenges, the aim of this proposal is innovation and step change in thermal management of AlGaN/GaN HEMT devices by developing novel substrates, in particular (1) high value substrates that have higher heat extraction capability than high cost SiC substrates commonly used for GaN RF applications, and (2) low cost substrates that have improved heat extraction capability to GaN-on-Si substrates for more cost sensitive power electronics markets. The resulting step-change in improvement in heat spreading will improve reliability, circuit efficiency and ease system constraints of GaN electronics. To enable the optimization of the thermal substrate properties key enabling new thermal analysis technologies will be developed. The UK has roadmaps for employing RF and microwave GaN electronics in defence as well as satellite communication. The key UK industrial players in this field include Selex, MBDA, Astrium & others, all requiring reliable and efficient GaN RF and microwave electronics, which the proposed work will advance and enable via the new heat extracting substrate technologies and improved methods of thermal characterisation, furthermore with opportunities for IQE UK, supporter of this proposal, of being a key component in the supply chain for RF GaN applications. The corresponding roadmap for power electronics requires cost-effective GaN presently on Si substrates power devices with UK based manufacture at NXP, supporter of this project, and International Rectifier (IR) which the outcome of this proposed work can innovate. Further business opportunities will emerge with the substrate development itself, such as via Element-6, at IQE through the developments of III-Nitride epitaxial growth for best heat extraction, or spin-out companies. Dissemination of results and insights from this project will be via publications in internationally leading journals, via conferences, via the UK Nitrides Consortium, i.e., established dissemination routes will be used to transfer knowledge into academia, and directly with the industrial supporters of this project, as well as other companies Bristol and Bath have links to (e.g. Selex, MBDA). The CDTR in Bristol and the III-Nitride group in Bath have both a strong track record in being successful using these dissemination routes, in particular with companies. The field of thermal management of semiconductor devices is an important academic research field, and is especially topical and useful at the current stage of implementation of this genuinely disruptive technology. It not only trains UK workforce for industry, but also it is essential to help maintain the present high level of device physics and engineering in the UK. It provides stimulus for an efficient interaction between universities and industry to maximize benefit of EPSRC research investment. This includes in this project interaction with UK industry, in particular, IQE, NXP, and Plessey in this project.

The UKRI Centre for Doctoral Training in Machine Intelligence for Nano-electronic Devices and Systems (MINDS-CDT) will operate as a centre of training excellence in the next generation of systems that employ Artificial Intelligence (AI) algorithms in low-cost/low-power device technologies: hardware-enabled AI. The use of AI in real-world applications through systems of interconnected devices (so-called Internet of Things) is increasingly important across the global economy. Various market surveys estimate the sector to be valued in the hundreds of billions, and project levels of compound annual growth of 25-30%. Applications of these technologies include smart cities, industrial IoT and robotics, connected health and smart homes. It is widely agreed that new advances in artificial intelligence and machine learning are key to unlocking the potential of these systems. Significant challenges remain, however, in the development of robust algorithms and coordinated systems that are efficient, secure, and work in concert with modern devices. Advances in electronics will soon hit atomic scales, requiring new approaches if we are to continue to improve hardware speed and power consumption. Novel nanotechnologies such as memristors have the potential to play a key role in addressing these challenges, but critical to their employment in real-world applications is how algorithms work in the context of device physics. Further, there are significant challenges around how resources available to devices (energy, memory, etc.) can more effectively adapt to the computational tasks at hand, again requiring us to think about how hardware and software work together. The MINDS CDT is unique in its cross-disciplinary research programme crossing emerging AI algorithms and models with advances in device technologies that underpin and enable their potential. To quote from one of our industry partners, "innovation is to come from software and hardware co-development" and that "this joined-up thinking as a potential game changer". The MINDS-CDT will train a substantial number of experts with the knowledge and skills to lead the development of this next generation of intelligent, embedded systems. The training programme will draw from both computer science and electronics expertise at the University of Southampton, and a substantial network of stakeholders from across industry, government and the broader economy. Core to our training ethos is the up-front investigation of the potential impacts of technological innovation on society, security and safety, and in the engagement of interest groups and the public in understanding the benefits as well as the risks of the use of these new developments in AI and technology for our society and economy. The processes we will use here include that all projects and research activities will be informed by in-depth impact assessment, and we will instigate an ambassadors programme for public engagement and, in particular, the engagement of underrepresented groups in AI and engineering.

Female academics, particularly in STEM subjects, score consistently lower than male academics in metrics measuring international [1] and industrial collaborations [2]. These two related assessment criteria are key at all stages in academic careers and particularly important at senior levels to secure the highest value research grants and promotions. While several barriers have been identified to academic career advancement for women and have led to strategic interventions at national and institutional levels, there remains a lack of data and action specifically targeting networking and collaboration - the focus of this VisNET programme. Our vision is 1) To identify key barriers to international collaboration for female engineering academics 2) To design and demonstrate interventions and new best practices in networking and collaborations to define a new and more effective normal. The emergence and rapid development of technologies that support geographically remote working relationships presents a timely opportunity. Effective use of such tools could help to correct the disadvantages experienced by women in international collaboration. We propose an intervention to determine and remodel the implicit 'rules' of networking and collaboration. This pilot project is aimed at a cohort of female post-doctoral researchers (PDRAs). Transition from post-doc to academic is a key attrition point for women in engineering. Success is reliant on demonstrating the means to develop academic independence. Possession of a strong network can be crucial. At the same time this group has relative freedom to trial new approaches of working and represents a critical mass to demonstrate and embed novel methods, including a route to involve more established academics. Thus, the interdisciplinary academic and industrial consortium we have brought together will lead the way in developing, integrating and advocating a new approach where networking and collaboration is conducted predominantly in situ (i.e. from home institutions). We believe that at this critical postdoctoral stage implementation of strategic networking and collaboration can be career defining, providing crucial routes to build confidence, establish future academic independence and funding success. Furthermore, it has the potential to mitigate the impact of future career breaks and parenthood. By demonstrating that networks can be built without frequent travel, it will also address the perception that an academic career is incompatible with work-life balance or family responsibilities, factors identified by junior researchers when consulted about their choice to leave academia [3]. While we see here an opportunity to have a rapid tangible impact on the academic career of a finite group of women, VisNET will also act as an effective route to embed our approaches into the working practices of our universities. Effective in situ networking has the potential to directly tackle negative perceptions of work-life balance in academia, contribute to the promotion of flexible working patterns and advance inclusivity for other minority academic communities such as academics with disabilities or remotely located. The coordinated outcome of this programme fits directly into EPSRC's and our Universities' strategic plans to build leadership, accelerate impact and balance capabilities ensuring the continued progression of UK emerging research leaders by enhancing their experiences and embedding career robustness. [1] Larivière et al., "Bibliometrics: Global gender disparities in science," Nat. News, vol. 504, no. 7479, p. 211, 2013 [2] Tartari & A. Salter, "The engagement gap: Exploring gender differences in University - Industry collaboration activities," Res. Policy, vol. 44, no. 6, pp. 1176-1191, 2015 [3] Shaw & Stanton, "Leaks in the pipeline: separating demographic inertia from ongoing gender differences in academia," Proc. R. Soc. B Biol. Sci., vol. 279, no. 1743, p. 3736, 2012