N22A-T021 TITLE: Affordable Stabilized Directional Antennas for Small Platforms

OUSD (R&E) MODERNIZATION PRIORITY: Networked C3

TECHNOLOGY AREA(S): Battlespace Environments;Electronics;Ground / Sea Vehicles

OBJECTIVE: Develop a low-cost inertially stabilized mechanism for motion compensation on antenna beam pointing and tracking aboard buoys and small crafts subject to winds, waves, and vehicle motion. Capability goals include low Size/Weight/Power (SWAP), high fault tolerance, and ability for customization and integration with representative antennas.

DESCRIPTION: Current small radio implementations for sensor exfil, telemetry, and data-on-the move lack the performance capabilities to connect small unmanned platforms to communication gateways separated by extended communication link ranges. Recent advances in antenna structures have proven significant increases in gain performance, thereby enabling link closure at farther ranges without increased transmit power. However, advanced inertial measurement electronics and algorithms are needed that can provide fine beam pointing, acquisition, tracking, stabilization (PATS) accuracy required in various environments. It is paramount this innovative solution has low cost, low size/weight/power (SWAP), high fault tolerance, ability for customization, and easy integration into different antenna configurations.

PHASE I: System engineering and trade study for phased array antenna motion-compensating electronics that consists of (i) industrial-grade low-cost commercial off-the-shelf (COTS) IMU/GPS, and (ii) signal processing of incoming IMU data to provide RF beam steering corrections at a rate 100 Hz or higher. Develop varied designs for acquisition, beam pointing and tracking accuracy and performance as a function of electronics/sensor cost, power consumption and size, taking into consideration the requirements for antenna beam width and PATS loss. Develop a case study with detailed design and architecture for integrating the beam correction to a representative phased array antenna up to sea state 4, or for land-based vehicle, on the move. Modeling and simulation results that captures and visualize real-time environmental dynamics and perturbations and their impact on maintaining the RF link stability is highly desirable. Propose solutions for identified gaps and performance improvements. Develop Phase II plans.

Produce knowledge-based deliverables: (1) technical trades and systems engineering addressing cost-size-weight-power and beam PATS loss; (2) architectural designs of stabilized antenna with integrated pointing/tracking in a few frequency bands of interest; and (3) down select prototype design to targeted small radio and antenna systems offering highest value-benefit for Naval stakeholders.

PHASE II: Develop working experimental prototypes based on initial architectural designs delivered in Phase I. Demonstrate the capabilities of developed prototypes in a relevant lab environment up to TRL 4/5. Continue additional integration and tests activities to elevate and achieve TRL 6 during the option Phase, if exercised.

Knowledge-based deliverables: Finalized targeted prototype design.

Hardware & Software deliverables: Prototype system(s) capable of being lab tested up to TRL 4/5. Over-the air limited range test desirable.

Metrics: Objective Size (< 10 cu. in.), weight (< 8 oz), and power (< 1 W); Low cost; Good Pitch/roll/heading accuracy at refresh rate up to 100 Hz; PATS loss < 3 dB for data link at maximum range

The Phase II Option, if exercised, will include the following deliverables and metrics: Integrated system(s) with local at-sea TRL 6 demonstrations of range and stabilization performance.

PHASE III DUAL USE APPLICATIONS: Develop and refine the final design based on Phase II. Include varied stress testing (extended temperature range, vibration, etc.). Demonstrate autonomous communication capabilities at extended ranges over various sea state environments.

Deliverables: Fully integrated systems on which to conduct rigorous testing with variable beam widths for robust autonomy, stabilization up to sea state 4 and on-the-move platforms, including SATCOM applications.

Private sector commercial potential includes autonomous observation systems, remote monitoring, ocean Internet-of-Things (IOT), and oil and gas exploration.

REFERENCES:

1. Smith, I.S.; Chaffer, E.A. and Walker, C. "Recent Developments in a Large Inflatable Antenna." IEEE Aerospace Conference, 3-10 March 2018, Big Sky, MT. https://ieeexplore.ieee.org/document/8396633.
2. Ganti, S.R. and Kim, Y. "Design of Low-Cost On-Board Auto-tracking Antenna for Small UAS." 12th Intl Conference on Information Technology � New Generations, 13-15 April 2015, Las Vegas, NV. https://ieeexplore.ieee.org/document/7113485.
3. Hoflinger, F. et.al. "A Wireless Micro Inertial measurement Unit (IMU)." 2012 IEEE International Instrumentation and Measurement Technology Conference, Vol. 62, No.9, May 2012. https://ieeexplore.ieee.org/document/6229271.

KEYWORDS: Phased array beam stabilization; Inflatable Antenna; Autonomous Communications