4-year fully funded PhD scholarship in the areas of transmitters and signal generation

Duration of study: Full time - 4 years fixed term
Application deadline: No closing date, the position will remain open 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: 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.

Read more:

[1] R. H. Walden, “Analog-to-digital converter survey and analysis,” IEEE J. on selected areas communications 17, 539–550 (1999).

[2] C. Deakin and Z. Liu, Noise and distortion analysis of dual frequency comb photonic RF channelizers, Opt. Express 28(26), 2020.

[3] C. Deakin and Z. Liu, "Frequency interleaving dual comb photonic ADC with 7 bits ENOB up to 40 GHz," 2022 Conference on Lasers and Electro-Optics (CLEO), San Jose, CA, USA, 2022, pp. 1-2. (highlighted paper).

2. Transceiver design for high capacity and resilient satellite communciations

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.

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 | UCL EPSRC Doctoral Training - UCL – University College London

Qualifications required: 

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 therefore strongly encourage applications from underrepresented backgrounds in engineering, such as women, ethnic minorities, or people with disabilities– EEE is a great place for you to study! We will make reasonable adjustments at interview and/or in the position as requested.

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.