Principal RF Systems Engineer

Commonwealth Fusion Systems

$150K — $225K *
Aerospace & Defense
11 - 15 years of experience
Job Overview by Ladders

Qualifications

  • Bachelor's degree in Electrical Engineering, Physics, or related field; Master's or Ph.D. preferred
  • Over 15 years of hands-on experience in high-power RF systems or related fields
  • Deep understanding of RF fundamentals, including diagnostics and design mitigation for RF arcs
  • Expert in RF circuit and electronics design with experience in EMI/EMC mitigation
  • Proficient in RF/Microwave simulation software (CST, HFSS, etc.)
  • Cross-disciplinary knowledge of embedded digital controllers, communications, and thermal design

Responsibilities

  • Shape system architecture for integrating RF plants with plasma loads
  • Guide the architecture and design of solid-state electronics systems
  • Spearhead design and integration of RF signal detection and controls
  • Tame the design and optimization of high-power transmission components
  • Mentor junior engineers while troubleshooting complex hardware issues

Benefits

  • Competitive compensation with equity
  • 13 company-wide holidays
  • Flexible vacation days
  • 10 sick days
  • Generous parental leave policy
  • Health, dental, and vision insurance
  • 401(k) with employer matching
  • Professional growth opportunities
  • Team-building activities
Full Job Description
Join the power movement as a Principal RF Systems Engineer

SPARC sustains fusion reactions by feeding >25MW of 120MHz RF power into the tokamak to heat the plasma to 100 million Kelvin. We need a Principal RF Systems Engineer to play a pivotal role in building the most powerful RF plant in the world.

At this level, you are a highly influential architect of the system. You will help drive the high-level technical direction while remaining deeply hands-on, taking a central role in the integration of high-power electronics, solid-state amplification, and complex transmission networks to ensure SPARC achieves net energy.

For more information on the SPARC RF plant, see the SPARC journal papers here:
  • Overview of the SPARC tokamak
  • Physics basis for the ICRF system of the SPARC tokamak


What you'll do:

  • Shape System Architecture: Play a critical role in the end-to-end design and integration strategy for RF plants for tokamaks, collaborating with other senior engineers to ensure seamless interaction between RF sources, matching networks, and the dynamic plasma load
  • Guide Solid-State & Electronics Integration: Act as a key driver in the architecture and design of the electronics ecosystems required to integrate massive, distributed RF systems, with a heavy emphasis on solid-state amplifier technology and associated power supplies
  • Spearhead Instrumentation & Control (I&C): Take the initiative in designing and integrating advanced RF signal detection, measurement circuits, and embedded digital controllers that interface seamlessly with SPARC's central data collection systems
  • Tame High-Power Delivery: Serve as a central figure in the hands-on design, integration, and optimization of critical high-power transmission components, specifically large-diameter coax lines and dynamic impedance matching networks
  • Hands-on Technical Mentorship: Act as a senior technical authority on the floor. You will be actively involved in commissioning equipment, troubleshooting the most complex system-level hardware discrepancies, and organically mentoring junior engineers to elevate the entire RF team's capabilities


What we're looking for:

  • Education: Bachelor's degree in Electrical Engineering, Physics, or a related field (Master's or Ph.D. strongly preferred for this level)
  • Experience: 15+ years of hands-on experience in high-power RF systems, radar, particle accelerators, or heavy industrial power electronics
  • RF Fundamentals Expertise: Proven intuition for high-power RF environments, specifically hands-on experience measuring forward and reflected RF power, diagnosing RF arcs, and designing the timing and electronics to mitigate them
  • Electronics & Design: Exceptional skills in RF circuit and electronics design (Altium or similar) specifically geared toward instrumentation, sensing, control, and system integration. Experience in EMI/EMC mitigation to ensure sensitive timing and RF detection circuits operate reliably within extreme high-power, high-noise environments
  • Advanced Simulation: High proficiency in RF/Microwave simulation software (CST, HFSS, etc.) to validate architectural decisions before physical integration
  • Cross-Disciplinary Fluency: A strong systems-level understanding of modern high-performance embedded digital controllers, high speed communications, and fundamentals of mechanical/thermal design to interface effectively with cross-functional teams


Must-have Requirements:

  • Perform activities such as stooping, climbing, typing, standing, or sitting for extended periods of time
  • Willingness to travel or work required nights/weekends/on-call occasionally
  • Work in a facility that contains industrial hazards including heat, cold, noise, fumes, strong magnets, lead (Pb), high voltage, high current, pressure systems, and cryogenics


$150,000 - $225,000 a year

Salary range for this full-time position + equity + benefits. The actual salary will depend on level, location, qualifications, and experience. The range displayed on each job posting reflects new hire salaries for the position across all US locations.

Benefits include:

Competitive compensation with equity

13 Company-wide Holidays

Flexible vacation days

10 sick days

Generous parental leave policy

Health, dental, and vision insurance

401(k) with employer matching

Professional growth opportunities

Team-building activities

#LI-Onsite

At CFS, we excel in fast-paced environments, driven by our values of integrity, execution, impact, and self-critique. As we grow, we're eager to bring on mission-driven folks who offer diverse perspectives and fresh ways to tackle challenges.

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