RF Test & Systems Engineer

RF Test & Systems EngineerOso Semiconductor is an early-stage fabless semiconductor company developing next-generation mmWave beamforming technology. Founded by UC Berkeley PhDs, our proprietary RFIC architecture delivers 2–4x power reduction for phased array systems across satellite communication (SATCOM), 5G, and radar. We've raised Series A funding, secured our first defense and commercial customers, and are preparing to scale the team 3X.We are looking for an RF Test & Systems Engineer to own the testing, characterization, and system-level validation of our mmWave beamforming chips and phased array platforms. This role sits at the intersection of RF testing, systems design, and applications engineering—you will prove our silicon works, build the systems around it, and help customers integrate it.ResponsibilitiesDesign, execute, and automate RF bench-top and over-the-air test plans for custom RFIC chipsets and phased array antennas. Own chip-level and system-level characterization.Architect and build phased array evaluation systems—PCB design, antenna integration, packaging interfaces, RF signal chain assembly.Perform EM simulation of phased arrays, RF passives, chip packages, PCBs, and antennas using Ansys HFSS and ADS Momentum. System-level signal chain modeling using MATLAB, Python, or Keysight SystemVue.Develop evaluation kits, reference designs, and technical documentation. Support customer design-in activities.Build and maintain RF test infrastructure including automation scripts (Python), calibration procedures, and measurement workflows.Work with RFIC designers, founding team, and customers to translate test results into design feedback.Required Qualifications5+ years in RF/mmWave testing, system design, or applications engineering.Proficient with RF test equipment: VNAs, spectrum analyzers, signal generators, power meters, and over-the-air test setups.Experience automating test equipment using Python and building repeatable measurement workflows.Experience in high-frequency (>6 GHz) phased array antenna PCB design, layout, and testing using Altium.Comfortable with EM simulation tools (Ansys HFSS, ADS Momentum) for antenna and package analysis.Strong understanding of RF front-end circuit blocks and theory.Advanced degree (MS/PhD) in EE or significant industry experience.Preferred QualificationsTheoretical expertise in multi-antenna wireless systems and phased array beamforming.System-level signal chain modeling (MATLAB, Python, Keysight SystemVue).Prior FAE or customer-facing technical role at a semiconductor company.Experience developing evaluation boards, reference designs, or customer hardware.Familiarity with chip packaging and its impact on RF performance at mmWave.Self-directed: takes ownership, builds what's needed, doesn't wait to be told.Why OsoFull ownership: Own the test and validation pipeline for a first-of-its-kind mmWave beamforming platform.Bridge role: Your work directly determines how our technology gets adopted by customers.Meaningful equity: Competitive stock option grant with real upside.UC Berkeley DNA: Work alongside PhDs with deep domain expertise.Dual-market: Defense (SATCOM, radar) and commercial (5G).What We OfferEquity: Stock option grant with 4-year vesting and 1-year cliff.Medical, Dental & Vision: Comprehensive health coverage with employer-sponsored medical, dental, and vision plans.Hybrid Schedule: Monday–Wednesday in office.Time Off: Unlimited PTO.401(k): Employer-matched retirement plan.Team Culture: Regular team lunches, events, and celebrations.Life Insurance: Company-paid life insurance.FSA & HSA: Flexible spending and health savings account options available.Commuter Benefits: Pre-tax transit and parking benefits.Oso Semiconductor is an equal opportunity employer. We consider all qualified applicants without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, veteran status, or any other protected characteristic.