Microwave Design Engineer arbeitnow Proxima Fusion GmbH Munich · 10/31/2026

Primetime; München; Hybrid; EUR 90,000 - 150,000; Full time

Job summary

Proxima Fusion is seeking a highly skilled microwave design engineer to advance millimeter-wave RF systems for the Alpha heating project. You will work on high-power components, 200 GHz frequencies, and the integration of RF with thermo-mechanical design in a fast-growing European team based in Munich.

You will collaborate with physicists and engineers across the Alpha Heating System group to ensure designs meet stringent plasma physics and thermal constraints, contribute to vendor assessments,

Qualifications

• Experience in millimeter-wave RF engineering.
• Familiarity with RF modelling tools: SURF3D, CST, COMSOL, GdfidL, openEMS.
• Experience validating first-of-a-kind designs with multi-physics simulations.
• Strong communication and teamwork skills.
• Knowledge of gyrotrons and related components preferred.

Responsibilities

• Develop RF and thermo-mechanical design for high-power components.
• Collaborate with physicists to meet plasma physics and thermal constraints.
• Evaluate vendor designs and optimize power delivery to the stellarator.
• Interface with project management to meet timelines.
• Contribute to mechanical and thermal analyses under vacuum, magnetic fields, and high RF loads.

Skills

Millimeter-wave RF

RF modelling tools

Python scripting

Gyrotrons knowledge

Team collaboration

Tools

SURF3D

CST

COMSOL

GdfidL

openEMS

Job description

Proxima Fusion is Europe’s fastest-growing fusion company and the continent’s best-funded fusion player, as well as the first spin-out from the Max Planck Institute for Plasma Physics (IPP). Backed by over €650M and powered by a growing team across Munich, Zurich, and Oxford, we are developing the hardware and infrastructure needed to deliver the world’s first commercial stellarator fusion power plant.

Our concept advances the most mature fusion technology out there, the Wendelstein 7-X stellarator, through two next-generation machines: Alpha and Stellaris. Our work combines stellarator optimization, advanced computation, machine learning, and high-temperature superconducting magnets to unlock higher-performance designs that were previously out of reach.

Turning these designs into a functioning fusion power plant requires excellence and ownership across every discipline, from physics and engineering to software, manufacturing, law, and business functions.

WHY JOIN PROXIMA FUSION

Work on a civilisation-scale problem - Clean, baseload fusion energy is one of the few genuinely world-changing challenges, and every hire in Finance, People, or Legal directly accelerates the path to a working stellarator.

Grow as fast as the company does - With headcount set to roughly 5x in a few years and major technical milestones ahead on the path to our demo machine and first power plant, your role grows under you; today's hire is tomorrow's function lead.

Tackle problems that don't exist elsewhere - Fusion sits at a rare intersection of deep-tech R&D, industrial procurement, government relations, and venture financing, so non-tech functions face challenges no other workplace can offer.

YOUR IMPACT

As a microwave design engineer, you will help build the basis for the millimeter wave hardware acting as the spark plug that initiates a fusion plasma and raises its temperature to greater than 100 million degrees. You’ll join the Alpha Heating System team ready to drive the integrated RF and thermo-mechanical design of high-power components, and help build and test these components in the lab before installing them at scale on our net scientific gain Alpha stellarator.

WHAT YOU WILL DO

Provide innovative solutions to complex RF engineering challenges by collaborating closely with physicists to ensure component designs meet the Alpha plasma physics and thermal-mechanical constraints.

Develop designs and evaluate vendor designs to determine an optimal path to efficiently deliver our power to the stellarator - driving down the denominator of input power that will limit fusion power plant gain Q=Pout/Pin - and drive down costs.

Draw from and contribute to our stellarator development process, interfacing your RF components with other stellarator systems.

Contribute to mechanical and thermal analysis and sensitivity studies for component viability under the loads and stresses imposed by the combination of vacuum, magnetic fields, temperatures, and MW-scale RF loads.

Interface with the Alpha project management teams to realize the delivery of RF components and meet the tight Proxima timelines.

WHO YOU ARE

A highly capable RF engineer with experience in millimeter waves and knowledge of the tools and best practices for design of these systems

Demonstrated familiarly with RF modeling codes - SURF3D, CST, COMSOL, GdfidL, openEMS, even self-developed python codes or ones plasma physics community hasn’t heard of - capable of performing modeling at 200 GHz frequencies

Experience validating first-of-a-kind designs with uncertain performance, working as part of a team on multi-scale and multi-physics simulations, testing, and prototyping.

Exceptional communication and interpersonal skills, with the ability to articulate complex technical concepts clearly and persuasively.

Experience with gyrotrons and associated components - transmission systems, launcher antennas, rf loads; experience with plasma physics is a plus.

Understanding of quasi optical propagation of millimeter waves; ray tracing and where it breaks down

Technical Screening (30 min)

Technical Panel (3x60 min)

*This role sits at "L2-L3" of our framework, please inquire during the recruitment process for further information.

At Proxima Fusion, our mission is bold: making limitless clean energy a reality. To get there, we need a high-performing, diverse team that brings different perspectives, challenges assumptions, and builds together with purpose. We know that diversity of thought and experience leads to better ideas, stronger execution, and a more resilient team. We don’t look at how you identify, what you look like, who you choose to worship or what ethnicity you are. We care about what you can bring to the table.

This overview was written from the original listing to help you understand the role. Always confirm the specifics on the employer’s application page.