Bristol Team to Develop Gallium Nitride on Diamond Microwave Technology

first_imgThe Engineering and Physical Sciences Research Council (EPSRC) has awarded a £4.3 million grant to the University of Bristol to lead an important new project to develop Gallium Nitride (GaN)-on-Diamond microwave technology. This next generation technology will underpin future high power radio frequency and microwave communications, space and defence systems, paving the way towards 5G and 6G mobile phone networks and much more comprehensive radar systems. Bristol will work with a consortium of four other universities (Cardiff, Glasgow, Cambridge and Birmingham) and leading industry partners during this five-year project.The global demand for high power microwave electronic devices that can deliver power densities well exceeding current technology is increasing. In particular Gallium Nitride (GaN) based high electron mobility transistors (HEMTs) are a key enabling technology for high-efficiency military and civilian microwave systems, and increasingly for renewable energy plants. Professor Martin Kuball, who is leading this project, gave an example – Information in a mobile communication systems is transmitted as ‘0’ and ‘1’s, so-called bits, and per bit this requires a certain amount of energy. In 5G, the number of bits transmitted per second will be immense, and future systems will ask for even more; current microwave devices which are used to transmit these bits in 4G networks do not have the muscle and power needed.The vision of this new project is to develop transformative GaN-on-Diamond HEMTs and monolithic microwave integrated circuits (MMICs), a technology step beyond current microwave devices.Energy flows in these can be as high as the heat flux on the surface of the sun, and the diamond with its ultra-high thermal conductivity is the only material which can handle them. These devices will allow the implementation of future communications networks and radar systems with capabilities beyond what is presently possible.For this vision to become a reality, the team will develop new diamond growth approaches that maximize diamond thermal conductivity close to the active GaN device area. In present research GaN-on-Diamond devices a thin dielectric layer is required on the GaN surface to enable seeding and successful deposition of diamond onto the GaN. Unfortunately, most of the thermal barriers in these devices, exists at the GaN-dielectric-diamond interface, which has much poorer thermal conductivity than desired.Any reduction in this thermal resistance, either by removing the need for a dielectric seeding layer for diamond growth, or by optimizing the grain structure of the diamond near the seeding, would be of huge benefit. Novel diamond growth will be combined with innovative micro-fluidics using phase-change materials, a dramatically more powerful approach than conventional micro-fluidics, to further aid heat extraction.The outcome will be devices with a spectacular (>5x) increase in RF power compared to the current state-of-the-art GaN-on-silicon carbide HEMTs, that are currently available. Another advantage of this solution will be the dramatic ‘step-change’ shrinkage in MMIC or power amplifier (PA) size, delivering an increase in efficiency through the removal of combining networks as well as a reduction in power amplifier cost. This represents a disruptive change in capability that will allow the realisation of new system architectures – for example, for radio frequency seekers and medical applications, and enable the bandwidths needed to deliver 5G and beyond. Reduced requirements for cooling/increased reliability will result in major cost savings at the system level.last_img read more

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Hilcorp Updates CIRCAC On Seismic Testing In Cook Inlet

first_imgHilcorp external affairs manager Lori Nelson: “Hilcorp has experienced delays in the permitting process, in part due to the government shutdown, required to begin our seismic survey this April.  We understand the waters of lower Cook Inlet are a shared resource.  Therefore, our team has made the decision to delay the survey until after the height of fishing and tourist season.” According to a release from CIRCAC, Hilcorp submitted its presentation–including an update on their Cook Inlet operations, seismic testing and the decommissioning of the Drift River Oil Terminal–in writing. Nelson: “We are actively engaged in discussions with our contractor to delay the survey.  Our commitment to keep the community’s interests and concerns at the forefront will continue as we work to revise our schedule and work plan.” According to Nelson these surveys provide the resolution needed for detailed geological evaluation and data resolution for placement of drill rigs or platforms. The release states: “We are proud of the role we played to advance the Cross-Inlet pipeline and Drift River Oil Terminal removal.” The company received a release from the Bureau of Ocean Energy Management in August of an environmental assessment ‘finding of no significant impact’. The bureau said the seismic survey, roughly 370 square miles, would have negligible effects on marine life and birds. Hilcorp has set up a hotline number for subsistence users to share information on seismic activity and is also hosting daily phone calls with subsistence users and local mariners with information about vessel location and activities. Seismic work is expected to be completed by October 31. The phone number is 907-777-8599. According to the presentation, progress is being made to dismantle the Drift River Oil Terminal. The facility’s pipes and storage containers are now oil-free. The oil in the ground, however, is a long-term Alaska Department of Environmental Conservation remediation clean-up project. The company  is now awaiting an official permit in order to begin the survey. Hilcorp originally planned to begin the survey in April, but delayed the plans until after the summer season. FacebookTwitterEmailPrintFriendly分享The CIRCAC Board of Directors met in Homer on September 6, with a full agenda of presentations from Hilcorp Alaska, LLC, the U.S. Coast Guard, and Tim Robertson from Nuka Research who provided an update on the Pipeline Assessment project. This survey will occur within the lower Cook Inlet, south of the Forelands and west to southwest of Homer. Hilcorp originally planned to start the project in April which would have allowed for completion in early summer. Hilcorp will conduct the seismic survey over 8 lease blocks to determine the location of possible oil and gas prospects during the 2019 open‐water season. Photo courtesy of CIRCAClast_img read more

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Neymar vows to work hard to be ready for World Cup

first_imgInjured Brazil striker Neymar has targeted May 17 for a return to training and vowed to work harder than ever to be ready for this year’s World Cup in Russia.The Paris St Germain player, who became the world’s most expensive footballer when he joined the club from Barcelona in August, had an operation on his foot after being injured in a French league game against Olympique de Marseille on Feb. 25.He has been receiving treatment in Brazil and said he expects to be training exactly a month before the five-times champions play their World Cup opener against Switzerland on June 17.“I get my final exam, if I’m not mistaken, on May 17 and then I’ll be free to play,” he told reporters at a news conference in Sao Paulo.“I had an exam last week, it is all perfect, evolving well, so I hope that continues so I can get back as soon as possible…“I am having treatment every day, and from the moment I start training I am going to work harder than I ever worked because this is a dream that’s coming up, it’s a World Cup. I’ve waited four years for this chance, it’s close and I hope to get there in great shape.”Neymar played for Brazil at the 2014 World Cup but missed the catastrophic 7-1 semi-final defeat by Germany through injury.Brazil struggled in the two years immediately after their home World Cup but have since rebounded and go to Russia as joint favourites with bookmakers along with Germany.Neymar, who joined PSG for a fee of 222 million euros ($275 million), said he was apprehensive about kicking a football again after almost three months out.“I expect to go (to the World Cup) in a better state than before,” he said. “Of course, doubts exist and I feel them too sometimes, but that’s normal for a guy who has had the first surgery of his career. It’s very difficult for me not playing and not training.”“I have to work even harder but I am going to have enough time to arrive in form for the World Cup, to prepare. It was horrible getting injured but I am more rested, that’s the upside. We have to see the positive side of things.”After opening their Group E World Cup campaign against Switzerland, Brazil face Costa Rica on June 22 and then Serbia five days later.last_img read more

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