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Design and Fabrication of Integrated Oscillator Circuits with Superlattice Electronic Devices

PGR-P-1406

Key facts

Type of research degree
PhD
Application deadline
Tuesday 31 January 2023
Project start date
Tuesday 1 August 2023
Country eligibility
International (open to all nationalities, including the UK)
Funding
Competition funded
Source of funding
University of Leeds
Supervisors
Dr Heribert Eisele and Professor Edmund Linfield
Schools
School of Electronic and Electrical Engineering
Research groups/institutes
Pollard Institute
<h2 class="heading hide-accessible">Summary</h2>

This project concerns the integration of a semiconductor device and a resonant circuit to form an oscillator at terahertz frequencies. The terahertz frequency range is located between the microwave and mid-infrared regions of the electromagnetic spectrum. It has long resisted full commercial exploitation owing to difficulties in fabricating convenient sources and detectors in large numbers. State-of-the-art results were achieved with superlattice electronic devices (SLEDs) in resonant waveguide circuits and required well-established, but extensive manual assembly. Integration of resonant circuits and SLEDs greatly facilitates portable commercial applications such as medical diagnostics and ultra-wideband wireless communications far beyond current 5G technology. The PhD project will develop and study various types of integrated structures and hence greatly enhance the performance boundaries of SLEDs. The project will involve device and high-frequency circuit simulations, a range of micro-fabrication techniques, and precision high-frequency measurements.

<h2 class="heading hide-accessible">Full description</h2>

<p style="margin-bottom: 11px;">The terahertz frequency range offers unique and well-known opportunities for scientific and commercial applications, but was many decades ago mainly known for its crucial benefits to radio-astronomy. It is located between the microwave and mid-infrared regions of the electromagnetic spectrum. This frequency range has long resisted full commercial exploitation owing to difficulties in fabricating convenient sources and detectors in large numbers; terahertz radiation is too high in frequency to be generated easily by the electronic techniques employed in, for example, mobile telephones and their base stations, but too low in frequency to be produced by the optical techniques exploited in, for example, lasers for CD players or optical communications.</p> <p>However, the last twenty years have witnessed a remarkable growth in the field owing to the development of innovative sources, detectors, and imaging systems. One of the innovative sources uses a semiconductor superlattice to produce a negative differential resistance (NDR) at the frequencies of interest. Such a negative differential resistance eliminates any damping from inevitable losses in a resonant LC circuit and thus yields clean terahertz oscillations at the resonance frequency of this circuit. State-of-the-art results were achieved with these superlattice electronic devices in resonant waveguide circuits. These results required well-established, but extensive manual assembly.</p> <p>Integration of resonant circuits with these superlattice electronic devices greatly facilitates portable commercial applications such as medical diagnostics and ultra-wideband wireless communications far beyond current 5G technology. These integrated structures will either be employed inside suitable waveguide structures mainly for precision high-frequency measurements or include antenna structures for radiating the signals into free space.</p> <p>The PhD project will develop and study various types of integrated structures and hence greatly enhance the performance boundaries of superlattice electronic devices from the current state-of-the-art results. The project will involve device and high-frequency circuit simulations, device and circuit fabrication in the University&rsquo;s superb cleanroom facilities, and precision high-frequency measurements. It envisaged that such integration techniques can be adopted for other NDR devices and that they will greatly help with the exploration of such devices as their frequencies of operation increase.</p> <p><strong>You can start your PhD studies from 1 August 2023 but you must be able to start by no later than 1 November 2023.</strong></p>

<h2 class="heading">How to apply</h2>

<p>Formal applications for research degree study should be made online through the&nbsp;<a href="https://www.leeds.ac.uk/research-applying/doc/applying-research-degrees">University&#39;s website</a>. Please state clearly in the Planned Course of Study section that you are applying for PHD Electronic &amp; Electrical Engineering FT and in the research information section&nbsp;that the research degree you wish to be considered for is <em><strong>Design and Fabrication of Integrated Oscillator Circuits with Superlattice Electronic Devices</strong></em> as well as <a href="https://eps.leeds.ac.uk/electronic-engineering/staff/297/dr-heribert-eisele">Dr Heribert Eisele</a> as your proposed supervisor.</p> <p>If English is not your first language, you must provide evidence that you meet the University&#39;s minimum English language requirements (below).</p> <p><em>As an international research-intensive university, we welcome students from all walks of life and from across the world. We foster an inclusive environment where all can flourish and prosper, and we are proud of our strong commitment to student education. Across all Faculties we are dedicated to diversifying our community and we welcome the unique contributions that individuals can bring, and particularly encourage applications from, but not limited to Black, Asian, people who belong to a minority ethnic community, people who identify as LGBT+ and people with disabilities. Applicants will always be selected based on merit and ability.</em></p> <p class="MsoNoSpacing">Applications will be considered on an ongoing basis. &nbsp;Potential applicants are strongly encouraged to contact the supervisors for an informal discussion before making a formal application. &nbsp;We also advise that you apply at the earliest opportunity as the application and selection process may close early, should we receive a sufficient number of applications or that a suitable candidate is appointed.</p> <p>Please note that you must provide the following documents in support of your application by the closing date of 31 January 2023:</p> <ul> <li>Full Transcripts of all degree study or if in final year of study, full transcripts to date</li> <li>Personal Statement outlining your interest in the project</li> <li>CV</li> <li>Funding information including any alternative sources of funding that you are applying for or if you are able to pay your own fees and maintenance</li> </ul>

<h2 class="heading heading--sm">Entry requirements</h2>

Applicants to research degree programmes should normally have at least a first class or an upper second class British Bachelors Honours degree (or equivalent) in an appropriate discipline. The criteria for entry for some research degrees may be higher, for example, several faculties, also require a Masters degree. Applicants are advised to check with the relevant School prior to making an application. Applicants who are uncertain about the requirements for a particular research degree are advised to contact the School or Graduate School prior to making an application.

<h2 class="heading heading--sm">English language requirements</h2>

The minimum English language entry requirement for research postgraduate research study is an IELTS of 6.0 overall with at least 5.5 in each component (reading, writing, listening and speaking) or equivalent. The test must be dated within two years of the start date of the course in order to be valid. Some schools and faculties have a higher requirement.

<h2 class="heading">Funding on offer</h2>

<p style="margin-bottom:12px"><strong>All students are welcome to apply.</strong></p> <p>A highly competitive School of Electronic &amp; Electrical Engineering Studentship consisting of the award of fees at the UK fee rate of &pound;4,596 or Non-UK fee rate of &pound;25,500 (currently for academic session 2022/23) together with a maintenance grant (currently &pound;17,668 for session 2022/23) for 3.5 years.</p> <p>This opportunity is open to all applicants. All candidates will be placed into the School of Electronic &amp; Electrical Engineering Studentship Competition and selection is based on academic merit.<br /> &nbsp;</p> <p><strong>Important:</strong>&nbsp; Any costs associated with your arrival at the University of Leeds to start your PhD including flights, immigration, health surcharge/medical insurance, and Visa costs are <strong>not</strong> covered under this studentship.</p> <p>Please refer to the <a href="https://www.ukcisa.org.uk/">UKCISA</a> website for information regarding Fee Status for Non-UK Nationals.</p>

<h2 class="heading">Contact details</h2>

<p>For further information about this project, please contact Dr Heribert Eisele<br /> e:&nbsp;<a href="mailto:h.eisele@leeds.ac.uk">h.eisele@leeds.ac.uk</a></p> <p>For further information about your application, please contact Doctoral College Admissions<br /> e: <a href="mailto:EMAIL@leeds.ac.uk">phd@engineering.leeds.ac.uk</a></p>


<h3 class="heading heading--sm">Linked funding opportunities</h3>