Senior RF Engineer

Eos Atomics is a San Francisco-based startup building commercial fusion technology to solve humanity’s most pressing energy challenge. We are a lean, technical team built for speed, precision, and uncompromised execution.We design, build, test, and deploy novel systems at record pace. We expect full technical ownership, high scientific rigor, and the curiosity to tackle problems others deem impossible.We debate openly, test relentlessly, and value ideas over hierarchy. If you want to push the frontier of fusion energy, you belong at Eos Atomics. Description The Role Eos Atomics is developing radio frequency systems on our current and next generation fusion devices.The systems will span a variety of operational frequencies and range of powers. In this critical role, you will be the core subject matter expert responsible for the end-to-end physics design and performance of our RF system. You will lead the architecture, high-power design, and commissioning of critical Radio Frequency (RF) heating and plasma diagnostic systems for our commercial fusion reactor. You will bridge the gap between high-frequency hardware design and fusion physics, and take ownership of the full RF design lifecycle. You’ll collaborate closely with cross-functional teams to turn novel concepts into reliable, field-ready hardware. You reach for whatever tool fits the problem best—whether that’s a quick first-principles calculation, a self-coded script, or a high-fidelity multiphysics suite. The method always serves the question. You treat fast, prototype testing as the primary engine of hardware design, rapidly incorporating real-world feedback into every design cycle. You take pride in full ownership, ensuring abstract concepts resolve into elegant, reliable, and high-performing physical systems. Core Responsibilities RF System Architecture Design & Optimization: Design and integrate MW-class RF transmission networks and matching units. Plasma Heating: Lead the development of high-power RF sources (including klystrons, gyrotrons, tetrodes, or solid-state power amplifiers). Impedance Matching & Load Variations: Develop active high-power tuning networks capable of dynamically matching rapidly varying load impedance. Extreme Environment Integration: Coordinate transmission designs to endure high neutron fluxes, vacuum-to-atmosphere boundaries, intense magnetic stray fields, and high thermal loads. Modeling & Simulation: Perform 3D full-wave electromagnetic and multiphysics simulations (HFSS, CST, COMSOL) to model wave propagation, arc suppression, and thermal management in transmission lines. Hardware & Integration: Collaborate closely with mechanical, electrical, and vacuum engineers to specify requirements. Commissioning & Test Safety: Lead high-power RF testing in the lab, including high-voltage conditioning, vacuum breakdown mitigation (Multipactor effect avoidance), and arc detection systems. Cross-Functional Leadership: Mentor junior/mid-level engineers, drive design review best practices, and contribute to standardizing internal RF development processes. Required Qualifications Education: B.S., M.S., or Ph.D. in Electrical Engineering, Applied Physics, or Nuclear Engineering with an emphasis on electromagnetics or RF systems. Experience: 6+ years designing high-power RF systems (pulse or CW), preferably in fusion energy, particle accelerators, defense radar, or high-power industrial microwave applications. Domain Expertise: Deep theoretical and practical knowledge of RF fundamentals and architecture. Proven experience working with kW/MW-level RF components, coaxial transmission lines, pressurized waveguides, and impedance matching structures. Ability to present complex RF problems in a simple and effective manner, identify and correct shortcomings in proposals and designs, and quickly gain new knowledge of RF systems to identify new approaches. Modeling Proficiency: Extensive experience with Matlab/Simulink or other applications used in modelling. Advanced proficiency in Ansys HFSS, CST Studio Suite, or COMSOL Multiphysics for high-power field analysis and arc/thermal modeling. Hardware Operations: Demonstrated track record working with RF hardware at multiple power levels, using solid state or vacuum tube technology. Strong hands-on laboratory diagnostic skills using RF test equipment, vacuum feedthroughs, arc-detection safety circuits, and high-voltage power supplies. Preferred Qualifications Experience mitigating the Multipactor effect and RF breakdown in high-vacuum, pressurized wave guides, and magnetized environments. Hands-on knowledge of pulsed power and Solid-State Power Amplifier (SSPA) combining techniques at kilowatt-to-megawatt levels. Familiarity with EPICS (Experimental Physics and Industrial Control System) or LabVIEW for automated RF system control and pulse timing. What We Offer Competitive Compensation & Equity. Success is shared. Competitive base and meaningful equity in the form of early-stage stock options. Benefits: Generous paid leave policy, paid holidays, and a company-wide December break Experience: Small team with low barriers to action, solving complex engineering challenges, building real hardware Impact: Direct ownership of first-of-a-kind systems without the red tape of traditional research facilities This position may require access to information or technology that is subject to U.S. export control laws, such as ITAR or EAR. Under these regulations, we are required to ensure that such access is provided only to individuals who are classified as 'U.S. Persons.' #J-18808-Ljbffr Eos Atomics