Full (UK and international) PhD scholarship opportunity in the areas of optical transmitters and signal generation

About the Project

Duration of study: Full time - 4 years fixed term

Application deadline: Until a suitable candidate is found

Primary Supervisor: Dr Zhixin Liu, Associate Professor in Department of Electronic & Electrical Engineering, University College London (UCL)

Project Description

We are looking for talented candidates to conduct PhD research in the areas of optical transmitters and signal generation.

1. Photonic analog to digital converter for high capacity and high-sensitivity mm-wave communications

The evolution toward mmWave communication in 5G, 6G, and satellite systems is pushing data rates and signal bandwidths to extremes — yet conventional electronic Analog-to-Digital Converters (ADCs) are becoming a bottleneck. Their performance is fundamentally constrained by timing jitter, electronic noise, and CMOS scaling, which limit both resolution and bandwidth, especially at high frequencies.

This project explores a disruptive solution: a photonic ADC that leverages ultra-low jitter optical frequency combs and >100 GHz-bandwidth modulators to enable high-resolution digitization of ultra-wideband signals in the mmWave domain.

You’ll work on:

• Developing and stabilizing ultra-low phase noise optical frequency combs
• Integrating and characterizing electro-optic modulators and subsystem components in the mmWave range
• Designing coherent receiver architectures optimized for high SNR and low distortion
• Investigating new methods for noise mitigation and digital signal reconstruction from photonic sampling systems

This research builds on an established experimental testbed at UCL and will be carried out in collaboration with Menhir Photonics, a leading manufacturer of high-performance optical combs. The outcome could redefine the front-end of high-frequency digitization — with applications in next-gen wireless infrastructure, quantum signal processing, and photonic sensing.

2. Transceiver design for high capacity and resilient satellite communications

Satellite communication is undergoing a major transformation. With the rise of LEO constellations like Starlink, OneWeb, and Amazon Kuiper, there's an urgent need for high-speed, low-latency, and weather-resilient transceivers that can reliably support massive data throughput — even in challenging conditions.

This project investigates the design and optimization of next-generation transceiver systems for satellite-to-ground communications, with a focus on achieving multi-hundred Gb/s links under realistic atmospheric and hardware constraints.

Key areas of research include:

• Comparative analysis of optical and microwave transceivers, including directly modulated lasers and coherent detection schemes
• Development and modeling of multi-wavelength transmitters and advanced photonic components
• Channel modelling and simulation under dynamic weather, orbital, and interference conditions
• Investigation of signal robustness, beam steering, and adaptive modulation for enhanced link performance

This PhD will give you the opportunity to design and prototype critical components for future space-based internet infrastructure, contributing to globally accessible, high-capacity communication systems that integrate seamlessly into 5G/6G hybrid terrestrial-satellite networks.

You’ll be joining a well-established photonics and communications research team at UCL, with access to state-of-the-art labs and facilities, as well as strong links to the broader UK and European space-tech ecosystem.

Who should apply

We’re seeking smart, driven, and curious individuals from physics or engineering backgrounds. Preferred experience includes one or more of the following:

• Optical communications / photonics
• RF or microwave systems
• Signal processing
• Integrated photonics
• Control systems

We value creativity and technical ambition — if you’ve got big ideas, we want to hear them.

Funding

This is a fully funded 4-year studentship. These studentships are open to those with Home and International fee status (including EU); however, the number of students with International fee status which can be recruited is capped according to the EPSRC terms and conditions so competition for International places is particularly strong.

More details about the stipend and fees can be found here: EPSRC Doctoral Training at UCL - Prospective Students

Eligibility

The candidate should pass the entry requirements of PhD programme at UCL EEE: https://www.ucl.ac.uk/prospective-students/graduate/research-degrees/electronic-and-electrical-engineering-mphil-phd

How to apply

Applications must be made using the UCL online application system by using the UCL postgraduate study application form. Please mark it to the attention of Dr Zhixin Liu. Applicants are encouraged to write a brief summary of research interests (max 200 words) to describe how his/her background fits the PhD projects. New ideas relevant to the research field are welcome.

Equality, diversity, and inclusion

Our research is driven forward by talented researchers and PhD students who come from countries and backgrounds across the globe. We strongly encourage applications from underrepresented backgrounds in engineering, such as women, ethnic minorities, or people with disabilities.

Contact

For informal inquiries please contact Dr Zhixin Liu (zhixin.liu@ucl.ac.uk) who will be happy to answer any queries about the project.