The Defense Systems Group at Leidos has an immediate opening for a Senior Principal RF Antenna Systems Engineer at our St. Petersburg, FL facility. This position serves as a senior technical authority and system architect supporting the development of advanced phased array antenna systems for mission-critical defense applications.

In this role, you will lead the architecture, design, analysis, integration, and fielding of complex RF antenna systems supporting Department of Defense and national security customers. You will provide technical leadership across multi-disciplinary engineering teams and serve as a key interface to customers, program management, and capture teams.

The St. Petersburg facility specializes in the design, modeling and simulation, prototyping, integration, and testing of advanced electronic systems, with a focus on embedded communications systems, Software Defined Radios (SDR), phased array antenna systems, and secure RF architectures operating in challenging and contested environments.

Primary Responsibilities:

• Serve as the technical lead and subject matter expert for the architecture, design, analysis, integration, and production of advanced phased array antenna systems supporting mission-critical defense applications.
• Lead and mentor a multi-disciplinary engineering team (RF, antenna, digital, mechanical, thermal, software) through concept development, modeling and simulation, hardware implementation, integration, and qualification testing.
• Develop antenna system concepts in collaboration with customers and program leadership, translating mission needs into clear, traceable system requirements and performance specifications.
• Lead requirements development, decomposition, allocation, and traceability to ensure system-level objectives are achieved across antenna, RF front-end, and supporting subsystems.
• Conduct and oversee trade studies evaluating performance, cost, risk, manufacturability, scalability, and lifecycle supportability.
• Provide technical oversight throughout design reviews (SRR, PDR, CDR), integration, verification and validation (V&V), and transition to production.
• Guide electromagnetic modeling, array simulation, beamforming architecture development, and performance validation activities.
• Develop and review technical documentation including system architectures, interface control documents, verification plans, test procedures, and qualification reports.
• Identify emerging antenna and RF technologies, industry trends, and modernization opportunities to inform program strategy and innovation.
• Support business development and capture efforts through white papers, technical proposals, RFI responses, and customer technical engagements.

Clearance Qualifications:

• U.S. Citizenship required.
• Ability to obtain and maintain a Secret Security Clearance.
• Active Secret clearance strongly preferred.
• Ability to obtain and maintain a Top Secret security clearance preferred.
• Willingness to work in classified laboratory environments and support secure development, integration, and test activities.
• Ability to comply with all program-specific security requirements, including handling of classified materials and controlled technical data (ITAR/EAR).

Basic Qualifications:

• Bachelor’s degree in Electrical Engineering, Electromagnetics, RF Engineering, or related discipline with 12–15+ years of relevant experience, or Master’s degree with 10–13+ years of relevant experience in phased array or advanced antenna systems.
• Extensive experience in the design, analysis, fabrication, integration, and test of complex phased array antenna systems, including planar, conformal (cylindrical/spherical), and other non-planar array geometries.

• Deep understanding of array theory, beamforming techniques (analog, digital, hybrid), mutual coupling effects, scan loss, grating lobes, sidelobe control, and calibration methodologies.
• Experience conducting near-field and far-field antenna measurements, including near-field to far-field transformation techniques and associated signal processing algorithms.
• Proficiency with full-wave electromagnetic modeling and simulation tools such as HFSS, FEKO, CST, or equivalent, along with analytical and data processing tools such as MATLAB.
• Demonstrated experience leading multi-disciplinary engineering teams (RF, digital, mechanical, thermal, manufacturing) and conducting formal technical design reviews (SRR, PDR, CDR, TIMs) with government customers.
• Experience transitioning antenna designs from prototype through qualification and production, including manufacturability and integration considerations.
• Working knowledge of system-level trade studies considering performance, cost, schedule, risk, and lifecycle supportability.
• Strong written and verbal communication skills with demonstrated experience presenting complex technical material to customers and senior leadership.

Preferred Qualifications:

• Advanced understanding of electromagnetic theory, phased array architectures, and RF/microwave system design, including system-level performance trade-offs and integration impacts.
• Experience developing and implementing advanced phased array algorithms, including adaptive beamforming, digital beamforming (DBF), null steering, interference mitigation, calibration techniques, and self-healing array architectures.
• Experience with distributed or networked array systems, hybrid analog/digital beamforming architectures, and real-time signal processing integration.
• Hands-on experience operating in compact range, near-field, and far-field antenna measurement facilities, including development of test plans, calibration methodologies, and automated measurement scripts.
• Proficiency with RF and microwave test equipment, including vector network analyzers (VNA), spectrum analyzers, RF power meters, signal generators, and phased array test systems.
• Working knowledge of the RF spectrum and modern communications infrastructures, including signal structures, propagation environments, modulation schemes, bandwidth considerations, and multiplexing/demultiplexing techniques.
• Experience supporting DoD radar, EW, SATCOM, SIGINT, or advanced communications programs.
•  Experience with manufacturability, producibility, and environmental qualification considerations (EMI/EMC, thermal, vibration).

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

February 23, 2026

Pay Range:

Pay Range $131,300.00 - $237,350.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.