Reconfigurable tensorial impedance surfaces for modulating RF scattering and antenna function (enhanced stipend) Ref: 5053
About the award
Prof Alastair Hibbins, Professor of Metamaterial Physics
Prof Simon Horsley, Associate Professor
Dr Ian Hooper, Senior Research fellow
Department of Physics, Streatham Campus, Exeter
The University of Exeter’s Centre for Metamaterials Research and Innovation (CMRI) with Dstl, is inviting applications for a fully-funded PhD studentship with enhanced stipend. For eligible students, the studentship will cover home tuition fees plus an annual tax-free stipend of at least £21,622 (UKRI rate + £3,000) for 3.5 years full-time, or pro rata for part-time study. There is also a budget to support your research project and training of at least £15,000. The student would be based in the Department of Physics and Astronomy within the Centre for Metamaterials Research and Innovation at the Streatham Campus in Exeter.
Anticipated start: Sept 2024
It is the focus of this project to design, model, fabricate and characterise active 2D metasurfaces that demonstrate a reconfigurable tensorial surface impedance [1-3] to enable temporal modulation of the amplitude, frequency, phase, directionality, or polarisation state of RF/mm-wave radiation. The findings will support future civil applications such as the internet of things, high frequency imaging systems for screening, scanners and tomography systems for medical diagnostics, and next-generation communication systems.
Reconfigurable metasurfaces  have garnered significant interest in the last 5 years as they promise a route to multifunctionality. However, developing reconfigurable tensorial impedance metasurfaces will enable an added degree of control over the scattering of radiation, or in the emission from an antenna adjacent to the surface. For example, one could design a curved surface that scatters radiation as if it were flat (or vice versa) and switch this behaviour off or on - this is something that a scalar impedance metasurface could never do. The extent to which the tensorial impedance of a surface can be actively reconfigured, and the extent to which this can alter the scattering of radiation from such a surface, or of the radiation emitted from an antenna adjacent to such a surface, will form the basis of this project.
At low frequencies (<10 GHz), reconfigurable metasurfaces typically consist of metallic structures with embedded diodes/varactors allowing electrical control of the local impedance, but these methods no longer work at higher frequencies such as those targeted for next-generation communications systems. However, at higher frequencies photoconductive control of the local conductivity of semiconductors has been suggested as a route to achieve similar functionality, with modulation rates of up to 10s of kHz demonstrated at Exeter . The benefits and limitations of both approaches will be explored.
The challenges are numerous and difficult, but we expect great advances in fundamental understanding and device design from a competent researcher. The project will include analytical, modelling, fabrication and experimental elements, and the student will be expected to interact closely with other researchers working in related areas.
 B. H. Fong et al., “Scalar and Tensor Holographic Artificial Impedance Surfaces,” IEEE Trans. Antennas Propag., 58 (10), 3212, 2010.
 R. Quarfoth and D. Sievenpiper, “Artificial Tensor Impedance Surface Waveguides,” IEEE Trans. Antennas Propag., 61 (7), 3597, 2013.
 “Tensorial metasurface antennas radiating polarized beams based on aperture field implementation,” International Journal of Microwave and Wireless Technologies, 10 (2), 161, 2018.
 B. Rana, S. -S. Cho and I. -P. Hong, "Review paper on hardware of reconfigurable intelligent surfaces," IEEE Access, 11, 29614, 2023.
 I. R. Hooper, N. E. Grant, L. E. Barr, L.E. et al., “High efficiency photomodulators for millimeter wave and THz radiation,” Sci. Rep., 9, 18304, 2019.
Due to funder restrictions, applications are are limited to those able to gain UK security clearance/
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 ensure to upload ALL items listed below through our application system. Incomplete applications cannot be processed.
Applicants for this studentship must have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK, in Physics or an appropriate area of science or technology.
If English is not your first language you will need to have achieved at least 7.0 in IELTS and no less than 6.0 in any section by the start of the project. Alternative tests may be acceptable (see http://www.exeter.ac.uk/postgraduate/apply/english/).
How to apply
To apply for funding, you must do so by clicking on the ‘apply now’ button above. In the application process you will be asked to upload several documents.
Please note our preferred format is PDF, each file named with your surname and the name of the document, eg. “Smith – CV.pdf”, “Smith – Cover Letter.pdf”, “Smith – Transcript.pdf
- You will need to provide a COVER LETTER that indicates your preferred area of study and/or preferred project,
- You will also need to upload a PERSONAL STATEMENT. We recommend that you describe (a) why you would like to study for a PhD; b) why you would like to focus on the identified area/project, c) any relevant expertise and d) your future career ambitions. We would also encourage you to describe the qualities that you believe will make you a great researcher (in particular as part of a team). Note: these details are not given in the application process but shortlisting will include assessment against these criteria.
You will also need to upload
- Transcript(s) giving full details of subjects studied and grades/marks obtained (this should be an interim transcript if you are still studying).
- Two references from referees familiar with your academic work. If your referees prefer, they can email the reference direct to[email@example.com quoting the studentship reference number. Please indicate this when you upload their details.
- If you are not a national of a majority English-speaking country you will need to submit evidence of your proficiency in English. Please see the entry requirements information above.
We intend to undertake interviews and make offers on a rolling basis following the deadline.
Note that we cannot accept references from personal/private email accounts, unless it is a scanned document on institutional headed paper and signed by the referee.
All application documents must be submitted in English. Certified translated copies of academic qualifications must also be provided (if applicable).
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
If you have any general enquiries about the application process or the project itself please email firstname.lastname@example.org
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 our research areas (see www.metamaterial.center);
• 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 normally be invited to an entry interview to assess fit to the cohort-based doctoral training programme, criteria above, and academic suitability.
Interviews are expected to start within two weeks upon application receipt. It is therefore advisable to apply as soon as possible.
|31st March 2024
|Number of awards:
|For eligible students the studentship will cover Home tuition fees plus an annual tax-free stipend of at least £21,622 for 3.5 years full-time, or pro rata for part-time study.
|Duration of award:
|Contact: Metamaterials admissions tutor