Expeditionary Very Low Frequency (ExVLF) Transmitter System

Area of Interest (AOI): Expeditionary Very Low Frequency (ExVLF) Transmitter SystemPAO Release Number: NAVWAR HQCA-2026-A-071Notice to Industry: This is an AOI issued under Naval Information Warfare Systems Command (NAVWAR) Commercial Solutions Opening (CSO) number N0003925S0001. This AOI solicits white papers/solution briefs (Phase 1 of the CSO) from industry. To the extent that any implementing regulations have not been updated to reflect statutory changes, the terms of the statute shall govern. Responses Due: 13-AUG-2026 at 2:00 PM PDTQuestions Due: 28-JUL-2026 at 2:00 PM PDTThe Government may not address all questions received. Questions and Answers will be posted on the NAVWAR CSO Website: https://www.navwar.navy.mil/Work-With-Us/Open-CSO-Calls/.Contact information for questions and technical/submission issues: ian.m.robinson14.civ@us.navy.milBackground:The Expeditionary Very Low Frequency (ExVLF) communications system is a modular, relocatable communications suite supported by an aerostat-lofted tethered antenna that enables 24/7 VLF radio wave data broadcasts over distance to maritime mobile and shore-based receive nodes.Problem StatementThe US Navy seeks solutions for an Expeditionary Very Low Frequency (ExVLF) transmitter system. The Navy requires a high-reliability solution that supports 24-hour per day, 7-day per week (24/7) data broadcast operations. As a result of this AOI, it is anticipated that initial efforts will focus on a prototype delivery phase, with potential options for follow-on production units to satisfy long-term operational inventory objectives. The system must be designed for deployment in rugged, multi-environment locations and integrate with Government-Furnished Equipment (GFE).Primary Solution Attributes:? High-Power Performance and Tuning: A containerized VLF transmitter system, consisting of a power amplification subsystem and a dynamic and automatic tuning element subsystem, designed to generate and radiate RF power by integrating with and automatically tuning to the specific complex impedance characteristics of a government-furnished Wireless Communications Aerostat (WCA) tethered antenna.? Integrated Transmitter System: The entire transmitter system must be housed within a no greater than 20-foot ISO general-purpose freight container to ensure it is transportable, deployable, and relocatable in diverse environments. The assembly must be hardened for deployment in rugged environments and include all necessary subsystems for operation.? Modulator and Signal Generation: An integrated subsystem to generate the required VLF waveforms. All signal characteristics, including modulation formats, reference frequency accuracy, and timing, must be sufficient to meet the top-level requirements of the ExVLF data broadcast mission.? Control and Monitoring System: A unified control system for local and remote operation of the transmitter. It should provide status monitoring, fault detection, and the ability to interface with the overarching ExVLF network command and control structure.? Mast and Feedline System: A deployable mast and feedline to provide the RF connection from the transmitter to the WCA mooring station.? Ground Plane System: A deployable ground plane system to ensure efficient RF radiation from the antenna system.? Interoperability: The system must be made interoperable with GFE, including a prepared flight pad, the WCA system, communications equipment, site logistics vehicles, and site power.Desired Solution Attributes:? Mobile Power Delivery System (MPDS): The MPDS provides the necessary operational power to the WCA (excluding transmission RF power). The Government seeks a full spectrum of solutions, both with and without an integrated MPDS. Additionally, we welcome proposals for a separately priced MPDS option. The MPDS shall provide power based on the aerostat vendors requirements; it shall function with or without RF power being transmitted; it shall fit within the primary transmitter e...