Senior RF Systems Architect — High-Power Fusion Tech

Commonwealth Fusion Systems LLC; Massachusetts; On-site; USD 150,000 - 225,000; Full time

Benefits offered by this job

Equity

Holidays

Flexible vacation

Sick days

Parental leave

Health insurance

Dental insurance

Vision insurance

401(k) matching

Growth opportunities

Team building

Job summary

Commonwealth Fusion Systems LLC is seeking a Principal RF Systems Engineer to architect and hands-on develop the SPARC RF plant, integrating high-power RF sources, amplifiers, and transmission networks to heat plasma and achieve net energy. You will lead system-level decisions, collaborate with senior teams, and drive robust electronics ecosystems for scalable fusion power hardware.

The role requires 15+ years in high-power RF, radar, accelerators, or related power electronics, with expertise in

Qualifications

• 15+ years of hands-on experience in high-power RF systems, radar, accelerators, or heavy industrial power electronics.
• Proven intuition for high-power RF environments, including measuring forward/reflected power and diagnosing RF arcs.
• Expertise in RF circuit design and EMI/EMC mitigation for extreme high-noise environments.
• Strong proficiency in RF/Microwave simulation tools (CST, HFSS) to validate architectural decisions.

Responsibilities

• Shape end-to-end RF plant architecture for tokamaks, coordinating with senior engineers to ensure seamless interaction between RF sources, matching networks, and plasma load.
• Guide the electronics integration, emphasizing solid-state amplifier technology and reliable power supplies.
• Spearhead instrumentation and control design for RF signal detection, measurement circuits, and embedded controllers interfacing with data systems.
• Tame high-power delivery by designing and optimizing large-diameter coax lines and impedance-matching networks.
• Mentor junior engineers on the floor, lead commissioning, and troubleshoot complex hardware discrepancies.

Skills

RF systems engineering

High-power RF

EMI/EMC mitigation

RF circuit design (Altium)

RF/Microwave simulation (CST/HFSS)

Embedded controllers

Power electronics

Education

Bachelor's degree in Electrical Engineering or Physics

Master's or Ph.D. preferred

Tools

Altium

CST

HFSS

Job description

Commonwealth Fusion Systems LLC is seeking a Principal RF Systems Engineer to architect and hands-on develop the SPARC RF plant, integrating high-power RF sources, amplifiers, and transmission networks to heat plasma and achieve net energy. You will lead system-level decisions, collaborate with senior teams, and drive robust electronics ecosystems for scalable fusion power hardware.

The role requires 15+ years in high-power RF, radar, accelerators, or related power electronics, with expertise in