Our research areas

Group leader: Dr Shyqyri Haxha

The Microwave Photonics and Sensors Group is focused on Microwave photonic signal processing, designing various ultra-high-speed optics communication devices and systems for applications in telecoms, sensors for real-time environmental and personal health monitoring applications, and Photonics (experimental) for High-Speed Quantum Key Distribution (QKD). The group is focused on wide range of theoretical, simulations and experimental research topics in Microwave Photonics, Photonic Crystal Structures, Metamaterials, Photonic Crystal Fibres, Solar Cell Nanostructures, Ultra-high-speed Optoelectronic devices and systems, Electro-optic  Modulators, Photonic Integrated Circuits, Nano-sensors, Optical Sensors for Medical applications, Biosensors.

Our focus
Our research group is focused on simulations and experimental investigation of the followings:

• All-optical processing and controlling of RF signals.
• Microwave photonic signal processing by exploiting intrinsic nonlinear effects in Optical Fibre for future Radar and Wireless communication Systems.
• Microwave Photonic Downconversion with high conversion efficiency using novel configuration schemes over a wide range of frequencies with high SFDR, low noise and suppression of high-order harmonics.

Aerospace
In civilian aerospace systems there is increasing demand for higher information capacity links to both ground stations and space based satellite networks for a wide range of applications including: on-board “Wi-Fi”, passenger and crew telecommunication and data communication, airframe and engine health monitoring systems, air traffic control communication, GPS and continuous airplane status and location monitoring.

Similarly in military aerospace live video feeds from the aircraft in addition to the continuous monitoring and control of on- board systems are envisaged. Photonics being largely Radio Frequency (RF) “blind”, hold the key prospect of combining multiple RF radios into a single architecture and antenna either through processing in parallel or serially in time. RF analogue photonic linking is a very promising technique due to the low insertion loss, system integration compactness, huge bandwidth capacity, security and immunity to EMI.

Collaborators
The Microwave Photonics and Sensors Group is collaborating closely with leading national and international industries and universities, working on the above stated research topic. Due to our close collaboration with industry, several patents have been filed jointly with the support from the industry. This page lists some, amongst other, areas of current interest as well as areas of opportunity for future work.

Working with us

To apply for an MSc by Research or PhD within the Microwave Photonics and Sensors, please email the Head of Group, Dr Haxha at shyqyri.haxha@rhul.ac.uk with details about your research interests as well as a summary of your academic qualifications (a brief one to two page CV will be useful) and if you are self-funded or require funding. After you have liaised with Dr Haxha, you will be able to register an account on Royal Holloway Direct to formally submit your application.

More details on the application process can be found here.

For more information on postdoctoral, fellowship and visiting opportunities, please email the Head of Group, Dr Haxha at shyqyri.haxha@rhul.ac.uk with your CV and a brief statement of your research interest and career aspirations..

The Microwave Photonics and Sensors group is working closely with leading industries, academies and local hospitals in the field where several patents have also been generated.

The group is working closely with physics, biosciences, materials, computer sciences and information security groups here at Royal Holloway, London University.

Group leader: Dr Wenqing Liu

Nano-electronics is an emergent interdisciplinary topic for the research of how nanotechnology can be used in Electronic Engineering. It covers a diverse set of advanced electronic materials and devices, with the common characteristic that they are so small that inter-atomic interactions and quantum phenomena need to be studied extensively.

This holds the fundamental answer for how people may increase the capabilities of the next-generation sensing, computation, and memory devices while reducing their size, weight, and power-consumption. The Department of Electronic Engineering performs cutting-edge research in nano-electronics by working closely with theorists and experimentalists in Physics, Chemistry, Biology, Material and Computer Science.

What is the Challenge?
Since the mid 20th century, the semiconductor-based IT industry has followed the famous Moore’s law that the number of transistors per square inch doubles approximately every 18 months. However, this trend will eventually hit a physical limit where the computation units enter the regime of nano-scale where quantum mechanisms start to dominate. In the overwhelmingly ‘big data’ revolution, demands for high processing speed and low energy dissipation computing technology have been rapidly increasing, yet the successes of the semiconductor electronics in the past on longer offer clear solutions.

Our Research
Our research covers a diverse set of advanced electronic materials particularly in their nano-forms. For applied materials, the spin ordering has long been investigated within the context of conventional ferromagnetic metals and their alloys, while the study of spin generation, relaxation, and spin-orbit engineering in non-magnetic materials has taken off rather recently with the advent of spintronics. It is here that many novel material systems can find their greatest potential in both science and technology. In the pursuit for such goals, the intrinsic material properties are important indicators and the artificially synthetized hybrid systems are valuable models for studying spin-dependent phenomena and could potentially be used as actual components for an eventual spintronic device.

What we use
The rise of nano-electronics has been strongly linked with the development of instrumentation in nanofabrication and characterization in the past thirty years. The experimental side of spintronic research today has marched to a historical point where the paramount urgency is to use materials of the highest perfection and homogeneity and detection tools with atomic sensitivity. Such criteria usually require expensive techniques, dedicated equipment and extreme physical conditions, e.g. ultra high vacuum, low temperature, and high field etc. Our research has been facilitated by several advanced fabrication and characterization techniques and we keep developing more.

Outlook
As an emergent interdisciplinary topic, Nano-electronics has promised not only new capabilities of electronic devices, but also interesting science. Our research aims to contribute to some of the most fundamental questions of the contemporary nano-electonics research, such as the FM/SC interfacial hybridization and magnetism, the spin and orbital ordering of ferrites, and the fundamental magnetism of doped TIs, and the proximity effect in heterostructures including FM/DMS, FM/TI and FM/SC. This will help the community fine pathway to mass production of spintronic devices.

Working with us

To apply for an MSc by Research or PhD within the Nano-Electronics Group, please email the Head of Group, Dr Liu at wenqing.liu@royalholloway.ac.uk with details about your research interests as well as a summary of your academic qualifications (a brief one to two page CV will be useful) and if you are self-funded or require funding. After you have liaised with Dr Liu, you will be able to register an account on Royal Holloway Direct to formally submit your application.

More details on the application process can be found here.

For more information on postdoctoral, fellowship and visiting opportunities, please email the Head of Group, Dr Liu at wenqing.liu@royalholloway.ac.uk with your CV and a brief statement of your research interest and career aspirations..

The Nano-Electronics Group collaborates with worldwide universities, research institutes, national laboratories and industrial partners. We acknowledge the support from YNJC, STFC, and EPSRC.

Group leader: Dr Stefanie Kuenzel

Power Systems is a research topic addressing many of the current challenges ranging from climate change to depletion of limited resources, ultimately aiming for a sustainable energy future. It covers a diverse set of topics, ranging from electricity generation to transmission and demand side management. Research in power systems enables a future with vast amounts of renewable generation including wind, photovoltaic and other emerging technologies. This future requires research in order to deliver a stable and reliable transmission system to transport the power and a smarter way of measuring power consumption and altering demand behavior. Through a collaborative approach, the Power Systems Group performs cutting edge research within the department as well as with external contacts from industry and academia.

Research background
Driven by climate change and limitations on the availability of fossil fuels, there have been major developments in research on power systems. New technologies have been developed for the generation, transmission and consumer side. These include renewable generation such as wind and photovoltaic generators, voltage source converters for ACDC power conversion, smart metering and demand side management. Research in power systems concentrates on “keeping the lights on”, maintaining the system frequency around 50Hz, reducing CO2 emissions and the use of fossil fuels and creating a sustainable future in the way we use and generate electricity.

Research topics
The Power Systems Group currently focuses on the following research fields: generation, transmission, distribution and demand. The research topic around generation includes transmission connected large scale generation, embedded generation in the distribution system or even smaller generation systems. Research on the very small scale structure which is used on photovoltaic panels has strong links with our Nano-Electronics Group. Research on the transmission side includes topics specific to HVDC transmission, other topics may be specific to the conventional HVAC transmission network. Demand side research can consider the impact of smart meters, the capabilities of demand side management as well as the consequences of introducing new types of loads to the network, such as electric vehicles.

Outlook
Wind farms have grown and have moved further offshore. As the distance to the shore is increasing, HVDC transmission from the wind farms common point of coupling to the main grid gains importance. The introduction of large amounts of wind generation, which is asynchronous leads to many research questions that have been investigated in the past years. The future may bring large scale integration of other renewable sources apart from wind and photovoltaics, which are still in an earlier stage of development. We cannot predict with certainty which generation mix future power systems will run on and how this impacts the transmission system. Demand side management will provide some added flexibility to respond to future challenges. With the government’s 2020 target for renewables we will see more renewable generation.

Collaborators
The Power Systems Group leader, Dr Kuenzel, has previously worked in collaboration with National Grid UK at the Warwick, Wokingham and Leeds offices, during her studies and early career. She has also collaborated as a postdoctoral research associate for the Stable-Net UK-China project and has been funded by the EPSRC. Dr Kuenzel has worked as a consultant for Imperial College London Consultants. During her research at Imperial College London, Dr Kuenzel's research group was awarded a President’s Team Award for Excellence in Research in 2016. Dr Juenzel functions as editor for IEEE Transactions on Sustainable Energy.The Power Systems Group at Royal Holloway has received a Leverhulme Magna Carta award for research into smart metering.

Working with us

To apply for an MSc by Research or PhD within the Power Systems Group, please email the Head of Group, Dr Kuenzel at stefanie.kuenzel@royalholloway.ac.uk with details about your research interests as well as a summary of your academic qualifications (a brief one to two page CV will be useful) and if you are self-funded or require funding. After you have liaised with Dr Kuenzel, you will be able to register an account on Royal Holloway Direct to formally submit your application.

More details on the application process can be found here.

For more information on postdoctoral, fellowship and visiting opportunities, please email the Head of Group, Dr Kuenzel at stefanie.kuenzel@royalholloway.ac.uk with your CV and a brief statement of your research interest and career aspirations.

Group leader: Professor David Howard

Crucial to human existence is our ability to communicate by voice (speech and singing) and maintaining our health. Increasing our understanding about voice production and hearing provides a route to improving analysis and communication systems in the future.

The Voice, Audio and Biosignals Group aims to deepen our understanding of how we hear sounds and further improve our acoustic analysis techniques.  Our second strand of research is concerned with analysing biomedical signals for diagnostic and therapeutic applications in active human health monitoring.

Voice development in singing
Singing is an activity that many indulge in and find deeply rewarding for a number of reasons. We are looking at voice development and voice change in girls (Professor Graham Welch, Dr Evangelos Himonides and I are recording girl choristers at Wells Cathedral on a regular 6-monthly basis) are making and boys (Professor Martin Ashley and I) who are and are not cathedral chorister with a view to improving understanding of the nature of the normal and pathological growing human voice.

Tuning in choral singing
How a choir tunes the notes of chords is basic to improving the overall sound, blend and listening pleasure for the audience and choir alike. Most important is the relationship between tuning and perceived consonance, which is heightened when the individual notes of chords are tuned in just temperament as opposed to equal temperament. On the face of it, this sounds like something that is easy to measure by tracking the fundamental frequency of the voice. However, there are other aspects that need to be considered that affect our perception of pitch and our work is looking at these. We have worked with a quartet from the auditioned Royal Holloway Chapel Choir.

Synthesis of speech
Speech synthesis is commonplace in many systems where a message needs to be communicated, but the synthetic output although highly intelligible, is rarely if ever mistaken as being from a human source. Understanding better what the acoustic cues in speech are that cue naturalness (as opposed to intelligibility) is the driver for this work, which is looking at the true 3-D shapes of the human vocal tract and how to synthesise speech from them. Work with the University of York (Department of Archeology) and Leeds Museum is looking at a historical vocal tract of an Egyptian Mummy.

The Vocal Tract Organ
This work is an offshoot from the synthesis using 3-D vocal tracts, and it makes use of 3-D prints of vowels that are placed atop loudspeaker drivers driven by a synthetic larynx source waveform whose pitch and amplitude can be varied. The organ can be played via a standard music keyboard or via joysticks. Performance with the organ have included a flash-mob opera after dinner events for the Royal Academy of Engineering, science fayres and public engagement sessions. The reason for this work is to investigate the organ's potential as a new musical instrument, including as a modern Vox Humana pipe organ stop with Harrison and Harrison Organ Builders in Durham (existing Vox Humana stops sound most unlike the human voice!).

Speech production and Parkinson's disease
The change in muscular control with the onset of Parkinson's disease also manifests itself in speech production and it is possible that this is earlier than limp tremor. We are working with Dr Steve Smith from the University of York (Department of Electronics) to explore the speech of patients with Parkinson's disease to explore whether their speech production with a view to assessing whether or not onset might be detected earlier.

Hearing modelling
A crucial part of all audio work is understanding better how the human hearing system works, which encompasses psychoacoustics, hearing physiology, neural carriage of information and high-level signal processing. Whilst much of this is impossible to measure directly, listening experiments can provide significant useful information that can be used to improve analysis systems.

Contact supervisor David Howard for details on potential PhD opportunties.

Biomedical Signal De-noising
With the increasing use of technology in medicine and the use of devices that acquire signals from the human body, there is a need to handle this data carefully. There are many biomedical signals of interest including, for example, Electro-Cardiograph (ECG), Electro-Encephalograph (EEG), Electro-Myograph (EMG) and Electro-Laryngograph (ELG) signals to name a few. All of these signals originate from the human body and suffer from interference and degradation during the acquisition phase. Typically these signals will suffer from baseline wander due to motion of the body, from mains line interference and often stray EMI in the form of spikes. Furthermore, these small electrical signals often interfere with one another. One of our research themes is the use of advanced signal processing techniques for the separation of these signals of interest from each other and from unwanted sources of noise.

Non-invasive cardiovascular disease risk prediction
Cardiovascular disease (CVD) is currently the primary cause of mortality in the world. Often, CVD goes undetected until complications appear and many sufferers go unchecked as insufficient resources are available for regular screening. Therefore, the early detection of the onset of CVD is vital for effective prevention and therapy. This research project proposes that the technique of Photoplethysmography (PPG) could be the basis for an inexpensive and effective method to assess cardiovascular disease risk. PPG is a non-invasive technique to measure cardiovascular health by sensing the change in blood volume in the finger pulp while the heart is pumping. A PPG sensor consists of an infrared LED that transmits an IR signal through the fingertip of the subject, a part of which is reflected by the blood cells. The changing blood volume with heartbeat results in a train of pulses at the output; this is often called the Digital Volume Pulse (DVP) waveform. It is envisaged that such a device could be connected to an embedded microprocessor via an analogue-to-digital converter for signal processing and analysis. A proof of concept of this technique for using the DVP waveform to assess cardiovascular fitness exists already and will form the basis of this research project. This research project will endeavor to further this work with original research into improved sensing and signal processing techniques to increase the sensitivity and specificity of the test.

Deep Learning for brain (EEG) signals.
Deep neural networks (DNNs) are one of the most popular and powerful machine learning systems used by companies such as Facebook and Google. It is therefore not a surprise that their successful applications have been in activities relevant to the cyber-world such as automated captioning of You Tube videos and facial recognition in Facebook images.  However, there is a lack of applications in exploiting the deep learning of neural networks for the analysis of biomedical data. In this direction, we have investigated how to reconstruct signals generated deep inside the brain from non-invasive measurements taken from the scalp. This is useful, as this circumvents the need to perform brain surgery to take a closer “picture” of the brain activities and can found applications in rehabilitation such as the prognosis of patients suffering from epilepsy. These brain signals called electroencephalogram (EEG) can also be analysed for other purposes such as the prediction of a person’s movement, the analysis/prognosis of diseases such as Parkinson’s disease and Schizophrenia, and monitoring of mental fatigue.

New Methods and Theories for 3D and 4D Signal Processing
Traditional signal processing and machine learning applications rely on the use of learning methods in the real- and complex-valued domains. However, modern technologies have fueled an ever-increasing number of emerging applications in which signals relies on unconventional algebraic structures (e.g., non-commutative). In this context, advanced complex- and hypercomplex-valued signal processing encompasses many of these challenging areas. In the complex domain, the augmented statistics have been found to be very effective in different methods of machine learning and nonlinear signal processing. However, processing signals in hypercomplex domains enables us to exploit some different properties, albeit raising challenges in designing and implementing new and more effective learning algorithms. More generally, learning in the hypercomplex domain allows us to process multidimensional data as a single entity rather than modelling as a multichannel entity, hence preserving the integrity of the data. In that direction, quaternions have attracted attention in the signal processing and machine learning communities for their capability of dealing with 3D and 4D models, thus providing an exciting area to propose new methodologies in signal processing.

Contact Supervisor Clive Cheong Took for details of potential PhD opportunites.

Working with us

To apply for an MSc by Research or PhD within the Voice and Audio Group, please email the Head of Group, Professor Howard at david.howard@royalholloway.ac.uk with details about your research interests as well as a summary of your academic qualifications (a brief one to two page CV will be useful) and if you are self-funded or require funding. After you have liaised with Professor Howard, you will be able to register an account on Royal Holloway Direct to formally submit your application.

More details on the application process can be found here.

For more information on postdoctoral, fellowship and visiting opportunities, please email the Head of Group, Professor Howard at david.howard@royalholloway.ac.uk with your CV and a brief statement of your research interest and career aspirations.