Principal Antenna Engineer

Kapta Space, a VC-funded early-stage startup in Seattle, WA, is breaking new ground in Geospatial Intelligence. Our technology centers around a proven, scalable electronically-steered radar for sophisticated spaceborne applications such as earth observation using synthetic aperture radar (SAR) techniques, as well as enabling advanced defense missions such as target tracking on the ground and in the air.

Kapta is seeking a Principal Antenna Engineer to lead the development of our radar antenna systems. The antenna engineer will be responsible for design, build and test of high frequency and millimeter wave electronically scanned antennas in collaboration with diverse engineering disciplines. This position requires a strong, self-driven engineer capable of working in a fast-paced, multi-disciplinary environment.

The ideal candidate will demonstrate the ability to apply advanced technical principles, theories, and concepts, and will have the drive and discipline to complete projects independently and on time. Kapta Space recognizes that strong candidates come from diverse backgrounds; if you bring relevant experience and the capacity to grow into this role, we encourage you to apply.

• Assist multi-disciplinary team in translating radar performance into antenna requirements, architecture, interfaces, and design trades.
• Design high-performance antenna systems and microwave circuits for use in c-SWaP-constrained systems.
• Develop tools for antenna and RF performance analysis within the larger radar system.
• Drive antenna hardware development efforts, working closely with vendors and suppliers to meet performance, cost, and schedule objectives.
• Test what you build! Take measurements and perform analysis of antenna and radar systems. Incorporate test data into system-level performance analysis.
• Optimize and calibrate antennas and antenna arrays for key performance metrics, including gain, side lobes, scan performance, bandwidth, and polarization purity over frequency and scan angle.
• Model array gain, scan loss, coupling, sidelobes, polarization, and spacecraft effects in HFSS/CST/FEKO.
• Build, test, and mature antenna, feed, and RF prototypes; partner with suppliers through qualification and production readiness activities.
• Support near- and far-field antenna test campaigns, leveraging measurement results to validate EM simulations, refine antenna designs, and assess radar system performance.
• Develop array calibration, beam-steering, and alignment methods with FPGA/DSP/software/RF teams.
• Optimize gain, efficiency, sidelobes, polarization, isolation, and phase/amplitude accuracy over scan.
• Support spacecraft integration and RF qualification across thermal, vibration, and thermal-vacuum environments.
• Drive technical problem solving, design reviews, and hardware maturation from early prototypes through flight-ready products.
• Develop, implement, and validate antenna control algorithms for advanced performance modes.
• Contribute to recruiting, interviewing, and hiring efforts to support team growth.

• BS, MS, or PhD degree in electrical engineering, electromagnetics, physics, or a related discipline.
• Onsite role in Redmond, WA.
• 10+ years of RF/antenna development, including phased arrays for radar or communications.
• Strong array theory: impedance matching, coupling, polarization, scan behavior, and beamforming.
• Proven track record of designing creative antenna systems that successfully balance multi-disciplinary engineering requirements.
• Familiarity with high-density PCB-based antenna design and fabrication
• Experience with phased-array design principles and digital beamforming (DBF)
• Proficiency with HFSS/CST/FEKO and Python/MATLAB for analysis, test automation, and model correlation.
• Hands-on VNA, spectrum analyzer, signal generator, and near-/far-field antenna measurement experience.
• High-frequency/mmW PCB antennas, feeds, waveguide/passives, prototyping, and strong cross-functional ownership.
• Demonstrated ownership of complex technical challenges from concept through implementation, validation, and deployment.

• Spaceborne phased-array/radar antenna design, spacecraft integration, and environmental qualification.
• Radar experience, especially SAR, GMTI/AMTI, performance analysis, high-power RF, or digital beamforming.
• Metamaterial, traveling-wave, leaky-wave, or other low-profile electronically scanned antenna architectures that balance performance vs cost.
• RFICs, beamformer ICs, custom ASICs, T/R modules, or mixed-signal control electronics.
• Ku/Ka-band or higher-frequency arrays, including waveguide, power handling, and low-loss RF implementation.
• Active DoD clearance or ability to obtain and maintain a Top-Secret security clearance.

Concerned you do not meet all the requirements? Not a problem - please apply even if you do not meet all these criteria.

$215,000 - $275,000 a year

The estimated salary range for this role reflects base pay only and is influenced by a variety of factors. Actual offers may vary based on—though not limited to—a candidate’s experience, education or training, specialized expertise, and the needs of the business. In addition to base pay, full-time roles include competitive equity grants that reward innovation, impact, and long-term growth. Our total compensation philosophy is designed to recognize excellence while fostering a culture of collaboration, curiosity, and shared success.

U.S. Citizenship, Lawful Permanent Residency, or Refugee/Asylee Status Required

To conform to U.S. Government space technology export regulations, including the International Traffic in Arms Regulations (ITAR), Kapta Employees must be U.S. citizens, lawful U.S. permanent residents (i.e., current Green Card holder), or lawfully admitted into the U.S. as a refugee or granted asylum, or be eligible to obtain the required authorizations from the U.S. Department of State or Commerce as applicable.

Kapta Space is committed to a diverse and inclusive workplace. We believe that diversity drives innovation, strengthens our team, and broadens our capabilities. We are an equal opportunity employer and do not discriminate on the basis of race, national origin, gender, gender identity, sexual orientation, protected veteran status, disability, age, or other legally protected status. We welcome applicants from all backgrounds and encourage individuals from underrepresented groups to apply.

Kapta Space does not engage with external recruiters or agencies without prior written agreement. If you are a recruiter (individual or agency) and wish to engage with Kapta Space for talent acquisition, please email View email address on aiapply.co.