Test Engineer

Job Title: Wireless Systems Embedded Firmware Engineer III Location: Sunnyvale, CA, Onsite role Duration: 6 monthsCandidates who can work independently without visa sponsorship in USA are eligible Role OverviewWe are seeking a Wireless Systems Embedded Firmware Engineer III / Cellular Test Engineer with strong hands-on experience testing 5G NR and LTE wireless devices. The ideal candidate will have experience with cellular protocol validation, RF performance testing, test automation, and laboratory hardware debugging.The engineer will work closely with firmware, RF, and hardware teams to execute test campaigns, automate regression testing, troubleshoot failures, and validate new wireless features and firmware releases.Key Responsibilities5G NR / LTE Test Execution & Validation:Execute conformance, functional, and regression testing on 5G NR SA/NSA and LTE devices.Test RRC/NAS signaling, mobility, carrier aggregation, and data throughput scenarios.Validate radio protocol behavior against 3GPP specifications.Perform RF measurements including TX power, sensitivity, EVM, spurious emissions, and throughput vs. signal level.Document test results and provide clear reproduction steps for failures.Test Automation — Rohde & Schwarz CMX/CMW:Build, maintain, and enhance automated test scripts and regression suites using Rohde & Schwarz CMX500/CMW callbox platforms.Own nightly/weekly automated regression runs.Monitor test results, troubleshoot failures, and maintain a stable regression suite.Develop Python-based tools for test sequencing, instrument control, result parsing, and reporting.Identify opportunities to reduce manual testing through automation.Lab Bench & Hardware Debug:Set up and operate laboratory test benches involving:CallboxesSpectrum/signal analyzersPower suppliesAttenuatorsShield boxesRF cablingUse oscilloscopes for signal integrity, timing, and power-sequencing troubleshooting.Determine whether issues originate from RF, cellular protocol, firmware, or hardware.Maintain calibration, cable-loss characterization, equipment health, and reproducible test configurations.Debugging & Cross-Functional Collaboration:Analyze QXDM/QCAT logs, modem traces, and callbox logs to identify root causes.Work with firmware, RF, and hardware engineers to reproduce issues and validate fixes.Track defects through resolution and escalate issues that could impact release milestones.Reporting & Continuous ImprovementPrepare daily/weekly test status reports covering:Pass ratesNew failuresCoverage gapsBlocking issuesContribute to test plans for new features, chipsets, and wireless bands.Expand test coverage where automation or scenarios are limited.Document test procedures, bench configurations, and known issues.Must-Have Skills5G NR and LTE cellular testing — protocol validation, RF performance, conformance and functional testing.Rohde & Schwarz CMX500/CMW — automated testing, callbox configuration, test scripts, and regression suites.RF/Hardware Lab Testing — oscilloscope, RF instrumentation, signal integrity, timing, and hardware debugging.Python scripting for test automation, instrument control, data/result parsing, and reporting.Strong understanding of cellular signaling and RF measurement fundamentals.Bachelor’s degree in engineering.Preferred QualificationsMaster’s degree in Computer Engineering or Electrical Engineering.Previous lab engineering experience.Strong engineering background with hands-on wireless testing experience.