Principal RF Engineer

AST SpaceMobile and our global partners are building the first and only space-based cellular broadband network to be accessible by standard smartphones. Called SpaceMobile, this ultra-powerful network is being designed to provide connectivity at 4G/5G speeds everywhere on the planet – on land, at sea and in flight. Position Overview We are seeking a Principal RF Engineer to support the design, analysis, and optimization of advanced satellite-based communications systems. This role is responsible for developing RF performance models, link budgets, and coverage analyses to evaluate end-to-end network performance across space and ground segments. The Principal RF Engineer will work closely with cross-functional engineering teams to assess system performance, optimize network availability, and support the development of reliable, high-capacity communications solutions. Key Responsibilities • Develop, maintain, and analyze uplink and downlink link budgets, including EIRP, G/T, path loss, atmospheric effects, antenna performance, fade margins, and system availability. • Create RF performance models to evaluate end-to-end communications performance under various operational and environmental conditions. • Analyze phased array antenna performance, including beamforming, scan loss, sidelobe behavior, coverage patterns, and beam isolation. • Evaluate the effects of Doppler shifts, propagation delays, latency, and user device constraints on network performance and capacity. • Collaborate with network, systems, and radio engineering teams to assess modulation, coding schemes, throughput, and overall service performance. • Develop and maintain feeder link analyses using industry-standard propagation models to evaluate weather impacts and network availability. • Assess and optimize fade mitigation techniques such as adaptive coding and modulation (ACM), power control strategies, and diversity solutions. • Perform system availability, sensitivity, and trade-off analyses to support infrastructure planning and performance optimization. • Analyze RF hardware impairments, including interference, phase noise, amplifier non-linearity, and other factors affecting system performance. • Develop simulations, analytical tools, dashboards, and reports to support engineering studies and operational assessments. • Establish performance requirements, validate design assumptions, and support verification activities throughout the development lifecycle. • Support troubleshooting efforts by developing performance baselines and assisting in root cause investigations. • Provide technical leadership and guidance on RF system analysis, architecture trade studies, and engineering best practices. Qualifications Education • Bachelor’s degree in Electrical Engineering, Telecommunications Engineering, Aerospace Engineering, Physics, or a related technical field. • Master’s degree in a relevant engineering discipline preferred. • Relevant industry certifications or specialized training in RF engineering, wireless communications, or satellite communications are a plus. Experience • Minimum 5 years of experience in RF systems engineering, satellite communications, wireless communications, or communications link analysis. • Experience developing and maintaining communication system link budgets and RF performance models. • Experience working with complex RF systems and multi-segment communications architectures. • Demonstrated experience leading technical analyses, trade studies, and cross-functional engineering initiatives. • Experience supporting communications infrastructure deployment, optimization, or operational performance assessments. Preferred Qualifications • Experience with satellite communications, non-terrestrial networks (NTN), or advanced wireless communication systems. • Familiarity with atmospheric propagation modeling and communications availability analysis methodologies. • Knowledge of adaptive coding and modulation, power control systems, and diversity techniques. • Experience with phased array antennas, beamforming architectures, and antenna calibration concepts. • Familiarity with systems engineering methodologies, requirements management, and performance validation processes. • Graduate-level coursework or advanced education in RF engineering, communications systems, or signal processing. Soft Skills • Strong analytical and problem-solving skills. • Excellent written and verbal communication skills. • Ability to communicate complex technical concepts to both technical and non-technical audiences. • Proven ability to collaborate effectively within cross-functional teams. • Strong organizational and project management skills. • Meticulous attention to detail and commitment to technical accuracy. • Ability to prioritize competing priorities in a fast-paced environment. • Self-motivated with a continuous learning mindset. Technology Stack • MATLAB • Python • RF modeling and simulation tools • Link budget analysis software • Data analysis and visualization tools • Microsoft Excel • Microsoft PowerPoint • Statistical modeling and reporting tools • Version control systems (e.g., Git) • Engineering collaboration and documentation platforms Physical Requirements • Ability to work in a standard office environment and use a computer for extended periods. • Ability to analyze complex technical data and review detailed engineering documentation. • Ability to participate in technical meetings, presentations, and collaborative design reviews. • Ability to remain stationary for extended periods while performing analysis, modeling, and documentation activities. Additional Requirements • Occasional travel may be required to support engineering reviews, testing activities, or operational sites. • Ability to lift up to 25lbs • Must be able to work effectively in a collaborative, multidisciplinary engineering environment. • Ability to manage multiple projects and tec