Communications Enhancements for Tactical Unmanned Autonomous Systems

The Communications Enhancements for Tactical UASs product is one of several products within the Global War on Terrorism Focused Persistent Tactical Surveillance Enabling Capability program. The communications enhancement product consists of two separate components: a modem and antenna.

The modem and antenna system must be able to support data rates of 300 Mbps up to 50 nautical miles in the Ka-band. The objective for modem development is low cost (less than $500); low size, weight, and power (less than 150 cubic centimeters and 0.4 kilograms) while supporting bandwidth efficient modulation and coding.

The antenna under development leverages Risley prism technology that was originally developed by another program at the Office of Naval Research, which demonstrated a prototype with 28 dB gain over a ±60° scan in the Ka frequency band. The Risley prism concept uses two dielectric wedges to focus the incoming electromagnetic energy from a specific direction onto the receiver feed horn. By rotating the two dielectric wedges relative to each other, it is possible to steer the antenna to the direction of the incoming electromagnetic energy. The ultimate goal is to develop an antenna system that is less than 5 pounds, with a form factor of less than 6 inches in diameter and 6 inches in height/

Prototypes of the Risley prism and modem were used to demonstrate the ability to establish a radio frequency link at distances up to 50 nautical miles in late 2009. Phase 1 flight testing occurred in June 2010, demonstrating a 150 Mbps data link. Phase 2 flight testing is planned for March 2011 to demonstrate a 300 Mbps data link. A final demonstration is planned for late 2012 with the optimized communications payload (including the modem and Risley prism) and a real-world sensor suite on a tactical UAS. The technologies will then be transitioned to the U.S. Marine Corps for integration into their platforms. The Communications Enhancements for Tactical UASs product enables affordable small UAV line-of-sight communications for intelligence, surveillance and reconnaissance that support small-unit operations and expeditionary warfare.