Principal Antenna Engineer

Kapta Space • Redmond, WA

5d • Onsite

About The Position

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.

Requirements

• BS, MS, or PhD degree in electrical engineering, electromagnetics, physics, or a related discipline.
• 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.
• 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.

Nice To Haves

• 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.

Responsibilities

• 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.

Benefits

• Competitive equity grants that reward innovation, impact, and long-term growth.
• Total compensation philosophy is designed to recognize excellence while fostering a culture of collaboration, curiosity, and shared success.

What This Job Offers

• Job Type: Full-time
• Career Level: Principal
• Education Level: Ph.D. or professional degree