RF Test Engineer

Job Title

RF Test Engineer

Role Summary

Operate and maintain the Jacksonville on-site RF/cryogenic test lab that produces measurement data for the device physics team. Own day-to-day measurements, instrument health, calibration discipline, and data handoff so remote physicists can make engineering decisions from reproducible results.

This position reports into the Cryogenic RF Test Infrastructure team and includes training junior bench staff and developing lab procedures and logs.

Experience Level

Mid-level. No explicit years-of-experience stated in the source.

Responsibilities

Primary responsibilities focused on running the RF/cryo lab, producing high-quality measurements, and maintaining instrument readiness.

• Operate RF and microwave instruments, dilution refrigerators, cryogenic probers, and associated microwave signal chain for measurement campaigns.
• Execute precision S-parameter, noise, and time-domain measurements at cryogenic temperatures and capture measurement metadata.
• Maintain and calibrate VNAs, cryogenic probers, cabling, connectors, fixturing, and the cold-chain signal path end-to-end.
• Define and enforce calibration schedules, cable/connector hygiene, equipment logs, and documentation to ensure reproducible data.
• Support scanning SQUID microscopy campaigns when required and train junior staff on measurement techniques.
• Investigate measurement discrepancies and perform root-cause analysis across fixtures, calibration, samples, and physical effects.
• Collaborate with device physicists, fabrication engineers, and test peers to tighten measurement methodology and feedback loops.

Requirements

Essential skills and practical experience required for independent operation of a measurement-intensive cryogenic RF lab; a short list of differentiators is provided.

• Must-have: Direct hands-on experience running RF/microwave lab equipment in measurement-heavy environments (bench time, not only simulation or design).
• Must-have: Experience in cryogenic test environments (dilution refrigerators, pulse tubes, cryogenic probers) with practical knowledge of thermal anchoring and cold-chain signal integrity.
• Must-have: Practical fluency with precision S-parameter, noise, and time-domain measurements, including calibration choices, error budgets, and fixturing considerations.
• Must-have: Demonstrated discipline in operational lab practices: calibration cadences, equipment logs, and reproducible documentation.
• Must-have: Proven ability to run and maintain equipment independently without on-site senior supervision.
• Nice-to-have: Experience with scanning SQUID microscopy, superconducting devices (SFQ, AQFP, qubits, detectors), millimeter-wave measurements above 20 GHz, low phase-noise characterization, or EM/microwave simulation used to explain measurements.
• Nice-to-have: Python or scientific computing skills for instrument control and measurement automation.
• Nice-to-have: Experience at national labs or research institutions (e.g., NIST, MIT Lincoln Lab, Sandia) in a cryogenic RF role.

Education Requirements

Not specified.

About the Company

Company: Snowcap Compute

Headquarters: San Francisco, CA, United States

Snowcap Compute develops commercial superconducting digital computers using Josephson junction–based PCL logic that operate at cryogenic temperatures, aiming for dramatically lower power than CMOS. The company combines expertise in quantum physics, cryogenic engineering, and semiconductor manufacturing to build production superconducting chips.