Senior RF Data Scientist / Research Engineer

Quell is a high-growth British defence and security AI technology start-up developing solutions to counter drone, vehicle, and human threats across the military, civilian and critical national infrastructure sectors.

Based near Cambridge, we are seeking exceptional Senior Radio Frequency (RF) Data Scientist / Research Engineers to work at the intersection of RF hardware, digital signal processing, and machine learning. You will analyse complex RF data from software-defined radios (SDRs), develop advanced signal-processing pipelines, and contribute to cutting-edge UAV/drone detection technologies. This is a hands-on R&D role suited to someone who thrives in fast-paced prototyping environments. It is a full-time role within the Research & Prototyping team.

Key Responsibilities

• Analysing raw IQ data from SDR platforms (e.g., bladeRF, USRP) to identify, classify, and extract RF signal features
• Building diagnostic tools for RF signal characterisation (e.g., time-frequency plots, cyclic spectra, EVM, autocorrelation, constellation tracking)
• Designing RF data-processing pipelines that account for real-world hardware constraints (bandwidth, gain stages, ADC limits, timing jitter)
• Modelling RF front-end behaviour (filters, mixers, LOs, AGC, noise figure) to improve signal integrity and inference accuracy
• Developing machine learning and statistical models for RF classification, anomaly detection, and emitter identification
• Prototyping real-time and batch-processing systems in Python (NumPy, SciPy, PyTorch) and integrating with ZMQ, GNU Radio, or C++ backends
• Leading RF data collection, field experiments, and over-the-air testing with drones, wireless devices, and custom transmitters

Requirements

• Strong Python proficiency for data analysis and prototyping (NumPy, SciPy, matplotlib, scikit-learn, PyTorch)
• Solid understanding of digital signal processing (FFT, filtering, modulation, correlation, noise modelling, resampling)
• Familiarity with SDR frameworks such as GNU Radio, SDRangel, osmoSDR, or SoapySDR
• Practical understanding of RF hardware chains (antenna -> filters -> mixers -> ADC) and their impact on baseband data
• Experience analysing wireless protocols (Wi-Fi, LTE, LoRa, etc.) and physical-layer structures
• Comfortable debugging SDR setups and carrying out field-based RF data collection
• Strong communication skills and ability to work in an iterative R&D environment
• Hands-on experience with SDRs (bladeRF, HackRF, USRP, PlutoSDR) and RF lab equipment (spectrum analysers, VNAs, signal generators)
• Experience with passive radar, beamforming, TDoA, Doppler, or direction finding
• Familiarity with embedded or real-time systems (e.g., FPGA pipelines, GPU acceleration)
• Programming experience in MATLAB, C++, Rust, or similar
• Knowledge of RF circuit fundamentals (impedance matching, filter design, gain budgeting)
• Experience designing or testing antenna arrays for sensing/detection
• Publications, patents, or open-source RF/ML contributions

Details

Location

• North Uttlesford / Greater Cambridge area, on-site
• Five days a week on-site (ie: this is not a hybrid role)
• Full UK driving licence required. If this isn't held, candidates will need to commit to obtaining within 6 months of their start date
• Applicants must be fully eligible to work in the UK without restriction, time limit, or the need for current or future sponsorship

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