RF/SDR Systems Engineer — Passive Radar (m/w/d)
Specter Sensing builds RF sensing systems for search and rescue, law enforcement, critical infrastructure and defence. One of our product lines is a passive radar that detects low-altitude drones using signals that existing 4G mobile networks already transmit, with no transmitter of our own. The processing chain is designed. We need the engineer who makes it run on real hardware, in real time, in the field.
You'll own everything between "the algorithm works on a recording" and "the system detects a drone outdoors, live." You'll implement DSP rather than invent it, working closely with our CTO, who leads the algorithm design. The role suits someone with substantial hands-on RF or SDR engineering experience who wants to own a system end to end.
What you'll do
- Build and own the capture chain: coherent, gapless, timestamped multichannel IQ from AD9361-class SDRs.
- Turn algorithm prototypes into a real-time Python pipeline that holds its latency budget.
- Design and measure the RF front end and antennas, including gain planning, filtering, and dynamic range against a direct-path signal that dwarfs any drone echo.
- Plan and run field trials with drones, with proper ground truth and synchronised recordings.
- Build and maintain the recording, replay and regression infrastructure the team develops against.
What you bring
- Hands-on SDR experience with AD9361-class hardware (bladeRF, USRP B2xx, Pluto or similar): streaming APIs, timestamps, gain modes, calibration.
- Experience making gapless multichannel capture work: USB3 host throughput, drop detection, buffer tuning.
- Real-time scientific Python: NumPy/SciPy/Numba, multiprocessing, shared-memory ring buffers, zero-copy, profiling.
- Practical RF front-end work: gain planning, noise figure, blocking, filter selection.
- RF measurement with spectrum analysers and VNAs, good cable and connector discipline, and antenna selection and placement. You're genuinely comfortable doing this outdoors.
Also valuable
- OFDM/LTE physical layer: you can read TS 36.211, know PSS/SSS and CRS, and have used srsRAN or similar.
- Radar fundamentals at implementation level: matched filtering, range-Doppler maps, CFAR, Pd/Pfa.
- Field test engineering: test geometry, ground truth from GNSS loggers and drone flight logs, time sync across IQ, logs and video.
- Test and data discipline: SigMF or HDF5 recordings, replay-based regression, Git, CI, Docker, and a critical eye when reviewing AI-generated code, which is part of how we work.
German and an EU drone pilot certificate (A1/A3 or A2) are a plus.
Eligibility
- Right to work in Germany.
- Our system is subject to EU dual-use export controls. You need to be eligible for access to controlled technology under EU and German export-control rules, and willing to undergo a German security clearance (Sicherheitsüberprüfung) where a project requires one.
- Fluent English, our working language.
- Regular outdoor field work and travel within Germany and the EU.
What we offer
- Ownership of a core system from day one, in a small team where your work ships.
- The hardware, lab and field access to build and test properly.
- Start as soon as possible.
We're an early-stage company. That means real influence over how the system gets built, and less structure than a large employer. We'd rather say so up front.
How to apply
Send your CV and a few lines about an SDR or RF system you built — including what broke and how you found it. No cover letter formalities, and no photo needed.
Apply for this role →Specter Sensing GmbH is an equal-opportunity employer. We welcome applications from all qualified people and select solely on the basis of professional qualification — regardless of age, gender, origin, religion, disability, sexual identity, or any other characteristic protected under the Allgemeines Gleichbehandlungsgesetz (AGG).
Applications are received and processed directly by the controller, Specter Sensing GmbH, and are used solely to assess your application for this role. Your rights and full details: Datenschutzerklärung.