Senior RF Engineer — Quantum Sensing Systems

Infleqtion, Inc.; Louisville (CO); Hybrid; USD 160,000 - 185,000; Full time

Benefits offered by this job

Medical coverage

Unlimited PTO

401(k) match

Equity program

Life insurance

HSA

Job summary

Infleqtion, Inc. seeks a hands-on Senior RF Engineer to establish the RF and electromagnetics discipline within the QRF team.

You will lead design, modeling, integration, and verification of broadband RF hardware for sensor heads and test environments on site in a lab setting. The role requires 5+ years in RF/hardware development, strong hands-on lab skills with VNA, oscilloscopes, analyzers, and experience with HFSS/CST/ADS.

Qualifications

• Bachelor’s degree in electrical engineering or equivalent practical experience.
• 5+ years of RF, microwave, or related hardware development.
• Hands-on lab experience with VNA, spectrum analyzers, signal generators, oscilloscopes, power meters.
• Knowledge of impedance matching, noise, phase noise, spurious response, leakage, and measurement uncertainty.
• Experience with RF design tools like HFSS, CST, or ADS.
• Experience with Python, MATLAB, or LabVIEW for automation and data analysis.
• Ability to own RF domain and connect RF decisions to quantum sensor performance.

Responsibilities

• Own RF and electromagnetic requirements, architectures, interfaces, performance budgets, and verification methods.
• Design, simulate, build, and characterize RF structures such as electrodes, resonators, antennas, fixtures, interconnects, shielding, and field delivery hardware.
• Develop RF signal generation, amplification, filtering, frequency conversion, local oscillator, distribution, and analog interface approaches that support broadband sensor operations
• Build and improve controlled conducted and radiated RF test environments, including field generation, field mapping, and calibration configurations.
• Define and execute measurements for field strength, frequency response, impedance, insertion and return loss, phase, coupling, shielding, noise, linearity, dynamic range, spurious response, and uncertainty.
• Build and maintain RF performance budgets for gain, loss, noise, phase noise, leakage, coupling, compression, harmonics, spurious signals, and other limits that affect sensor performance.
• Lead RF hardware bring-up, characterization, troubleshooting, and root-cause analysis across benchtop, subsystem, sensor head, and integrated system configurations.
• Use electromagnetic and circuit simulation to guide hardware and test fixture design, component selection, design trades, and interpretation of measured results; reconcile models with laboratory data.
• Develop Python or comparable automation for instrument control, parameter sweeps, calibration, regression testing, data analysis, and technical reporting.
• Work with applied physicists to relate RF field delivery and signal-chain behavior to atomic response, sensitivity, bandwidth, stability, dynamic range, and repeatability.
• Collaborate with optical-mechanical, electrical, embedded-systems, software, manufacturing, and technician personnel to define interfaces, resolve cross-domain problems, and transfer RF designs into repeatable builds and acceptance tests.
• Document designs, models, interfaces, calibration methods, test procedures, configurations, results, trade studies, risks, and recommendations for technical reviews, verification, and future production.

Skills

RF design

EM simulations

Test & measurement

Automation

Python

Education

Bachelor's degree in electrical engineering

Equivalent practical experience

Tools

Ansys HFSS

CST Studio Suite

Keysight ADS

Cadence AWR

COMSOL

FEKO

Job description

Infleqtion, Inc. seeks a hands-on Senior RF Engineer to establish the RF and electromagnetics discipline within the QRF team.

You will lead design, modeling, integration, and verification of broadband RF hardware for sensor heads and test environments on site in a lab setting. The role requires 5+ years in RF/hardware development, strong hands-on lab skills with VNA, oscilloscopes, analyzers, and experience with HFSS/CST/ADS.