Neptune Payload Prototype Project

S²MARTS Project No. 21-10

The Office of Naval Research (ONR) requires a prototype subminiature Radio Frequency (RF) signal processing payload subsystem for integration into a maritime system of expendable unmanned systems. In order to support multiple RF missions with a limited set of hardware, a wideband transceiver capability with self-contained software-defined or reconfigurable hardware-accelerated processing is required.

Commercial software defined radio technology is well defined. Candidate component technologies that are available for integration to satisfy ONR’s payload requirement include currently available integrated wideband RF transceiver chipsets, Field Programmable Gate Array (FPGA), RF Application Specific Integrated Circuit (RF ASIC), Radio Frequency System-on-Chip (RFSoC), and high-performance microcontrollers.

It is expected that current high Technology Readiness Level (TRL) or COTS software defined radio designs may meet some technical objectives, but will require varying levels of modifications to:

  • Mechanical design e.g., shape of boards / housings, type/orientation of connectors, mounting considerations, etc.
  • Electrical design e.g., power conditioning for battery operation, defeaturing of designs to remove unneeded development interfaces (such as USB / HDMI / Ethernet)
  • RF design e.g., tailoring of band-specific front-end variants
  • Firmware / software / processing e.g., secure storage of operational software, external selection / activation of operating mode / function, zeroization / end-of-run behavior, implementation of additional customer specified operational functions
  • Hardening / ruggedization for a maritime application

The expendable unmanned system that will house the Neptune Payload Prototype will be developed/evolved in parallel by the government team. It is expected that design information will regularly be exchanged during the effort to promote early identification and resolution of integration challenges.

Key technical objectives of the desired Neptune Payload Prototype subsystem include overall mechanical and electronic compatibility with the target platform, RF performance suitable for various maritime RF missions, and security of mission data / operational firmware / software. A balance between performance / capability and cost is desired to provide an expendable device that can be affordably fielded in quantity sufficient to make employment feasible.