CDT in Metamaterials: Miniaturised helical antennas for superdirectivity Ref: 3885
About the award
Statement of Research
External partner: Defence Science and Technology Laboratories (DSTL)
Beginning from fundamental physics, over a century ago, Marconi pioneered radio communication. He could surely never have imagined Jodrell Bank or the country strewn with antennas of numerous designs and functionality required for everything from wireless key fobs, to WiFi communication, TV reception and radar, but that is where we now are. Such devices often need to collect a weak signal or in the case of transmitters provide highly directed signals from ground, up to satellites. There is however one way this use of cumbersome dishes may be overcome, using the phenomenon of superdirectivity. Unlike conventional cumbersome phased arrays that provide high directivity by means of constructive interference, superdirective antennas are based on destructive interference that suppresses radiation in all directions. However for a suitable design in one specific direction this destructive interference is minimised and hence the radiation in that chosen direction is a relative maximum. This, in theory, makes it possible to obtain an arbitrarily sharp beam which may readily be steered to a chosen receiver.
Recently at Exeter we have demonstrated a novel superdirective dimer arrangement consisting simply of two metallic helices placed a suitable distance apart. This very small structure, much less than a wavelength in size unlike the large dishes normally used, gives very high directivity for low GHz frequency microwaves.
This research project seeks to take this superdirective work to a new level.
Firstly the researcher will explore the use of combining the superdirective dimers with ‘magnetic mirrors’ formed of arrays of resonant helices (we have already demonstrated their effectiveness for a bow-tie antenna.). This will allow this newly developed miniaturised microwave source to be used in proximity to conducting objects.
Secondly they will explore even stronger superdirectivity using 3 or more helical antennas.
Thirdly they will pioneer studies of concentric arrangements of helices, possibly of opposite handedness, to even further miniaturise the source, making it even lighter and smaller while still maintaining high directivity.
In all three cases we shall begin by modelling based around our previous experience and then move on to sample fabrication and characterisation.
The work forms part of a very strong collaboration with, and is fully sponsored by, the UK Government agency, Defence Science and Technology Laboratories (Dstl).
The work involved ranges from very fundamental physics, through modelling and on to device design, fabrication and testing. The successful applicant must have a very good degree in Physics or Electrical Engineering and be a UK or EU National.
The studentship is part of the UK’s Centre of Doctoral Training in Metamaterials (XM2) based in the Departments of Physics and Engineering on the Streatham Campus in Exeter. Our aim is to undertake world-leading research, while training scientists and engineers with the relevant research skills and knowledge, and professional attributes for industry and academia.
The 4 year studentship (value approx. £105,000) is externally funded by an industry partner. It is of value around £105,000, which includes £13,000 towards the research project (travel, consumables, equipment etc.), tuition fees, and an annual, tax-free stipend of approximately £16,500 per year for UK/EU students.
Eligible candidates: UK nationals only due to industry sponsor requirements.
Exeter has a well-established and strong track record of relevant research, and prospective students can consider projects from a wide variety of fields:
- Acoustic and Fluid-dynamical Metamaterials
- Biological and Bio-inspired Metamaterials
- Graphene and other 2D Materials, and related Devices
- Magnonics, Spintronics and Magnetic Metamaterials
- Microwave Metamaterials
- Nanomaterials and Nanocomposites
- Optical, Infra-red and THz Photonics and Plasmonics
- Quantum Metamaterials
- Wave Theory and Spatial Transformations
The studentship is subject to funding availability.
Metamaterials are fabricated microstructures having properties beyond those found in nature. They are an important new class of electromagnetic and acoustic materials with applications in many technology areas: energy storage and improved efficiency, imaging, communications, sensing and the much-hyped ‘cloaking’. Since 2014, the Centre for Doctoral Training in Metamaterials (XM2) recruited over 80 PhD students. Learn more about our science and training approach: www.exeter.ac.uk/metamaterials.
The first year of the studentship includes an assessed, stand alone project, and a substantial programme of training. Students will choose from a wide range of taught modules, and participate in academic and personal development skills-based workshops, together with creativity events and conference-style meetings. The cohort will also be expected to disseminate their results to the international community via high-impact publications and international conferences. They will spend time working with our academic and industrial partners. Full details of the programme are available here.
The University of Exeter combines world class research with excellent student satisfaction. It is a member of the Russell Group of leading research-intensive universities. Formed in 1955, the University has over 20,000 students from more than 130 different countries. Its success is built on a strong partnership with its students and a clear focus on high performance. Recent breakthroughs to come out of Exeter's research include the identification and treatment of new forms of diabetes and the creation of the world's most transparent, lightweight and flexible conductor of electricity. Exeter is ranked amongst the UK’s top 10 universities in the Higher Education league tables produced by the Times and the Sunday Times. It is also ranked amongst the world’s top 200 universities in the QS and Times Higher Education rankings.
How to apply
Eligible applicants: UK or EU nationals only.
Applications are made to the Metamaterials programme for a PhD in Physics/Engineering. We invite candidates to specify their project(s) of interest at the time of application.
Please send your application consisting of ALL items listed below to firstname.lastname@example.org. Please note, incomplete applications cannot be processed.
- Degree transcript(s) giving information about the qualification awarded, the modules taken during the study period, and the marks for each module taken.
- An academic CV;
A cover letter outlining your research interests in general, the title of the project you are applying for;
- Describe a) why you would like to study for a PhD, b) why you would like to focus on this particular topic, c) any relevant expertise and d) your future career ambitions;
- Describe the qualities that you believe will make you a great researcher (in particular as part of a team).
- The contact details of two academic referees.
* We foster creativity and utilisation of individual strengths. Applicants are encouraged to provide evidence to support their statements. This might include conventional written documents (e.g. examples of work), but we also encourage alternatives such as audio or video recordings, websites, programming etc. Please ensure to include accessible links to such files in an appropriately named document as part of the upload process.
Applications will normally be reviewed within two weeks of receipt.
Candidates will be short-listed against a set of agreed criteria to ensure quality while maintaining diversity. Failure to include all the elements listed above may result in rejection.
The essential criteria:
- Undergraduate degree in a relevant discipline;
- Vision and motivation (for research & professional development);
- Evidence of the ability to work collaboratively and to engage in a diverse community;
- Evidence of excellent written and oral skills in English.
The highest quality candidates will also be able to demonstrate one of more of the following:
- Specialist knowledge about one or more of the 8 research areas listed above;
- Training in research methodology (e.g. undergraduate research projects);
- Research outputs (e.g. papers) and/or other indicators of academic excellence (e.g. awards).
Shortlisted candidates will be invited to an entry interview to assess fit to the CDT concept. This will be held prior the academic interview with the supervisors and will normally be undertaken by a panel of 3 people, including a current postgraduate researcher or post-doc in Physics or Engineering.
Interviews are expected to start within two weeks upon application receipt. It is therefore advisable to apply as soon as possible.
Please email email@example.com if you have any queries about this process.
|Application deadline:||31st March 2020|
|Number of awards:||1|
|Value:||Approximately £105,000, including research and travel budget, tuition fees and annual taxfree stipend (approx. £16,500 per year payable to UK or EU students only).|
|Duration of award:||per year|
|Contact: Dr. Isaac Luxmoore (Admissions Tutor)||firstname.lastname@example.org|