Systems and Techniques for Developing Full-Duplex Multi-Functional HF Antennas
Abstract
The objective of this project is to develop the key components and techniques needed to enable multi-functional HF antennas capableof supporting robust full-duplex operation. Due to the large wavelength of electromagnetic waves at HF band, existing HF systems often use physically large antennas or compromise radiation efficiency if small antennas are employed. Moreover, the near-field regionof an HF antenna extends tens to hundreds of feet into the surrounding region causing a significant interaction between the antennaand its environment (e.g., earth, seawater, etc.) as well as other antennas in the vicinity. These interactions often change considerably with time due to platform movements, environmental changes, or tuning of nearby antennas and result in a dynamic interferencescene. Consequently, the self- and co-site interference (SI/CSI) problems in existing HF antenna systems are very complex, making full-duplex operation extremely challenging if not impossible.To achieve the primary objective of this project, we plan to develop adaptive matching and decoupling networks (AMDNs) for use in multi-functional HF antenna systems having two or more radiating elements. AMDNs will both impedance match and isolate the closely-spaced HF antennas of a multi-functional HF system thereby alleviating theSI/CSI problems in such systems. Moreover, AMDNs will be designed to dynamically adapt themselves to a changing antenna environment(e.g., caused by phenomena such as changing of ground type or detuning of nearby antennas) and maintain the desired impedance matching and antenna isolation levels. We will investigate the design, optimization, and synthesis of AMDNs suitable for use in multi-antenna HF systems. Using machine learning techniques in conjunction with near-real-time sensing of the antenna parameters, we will develop techniques to predict the future system state in a multi-functional HF system. This is expected to facilitate the tasks of adapting the system to compensate for the changes in the antenna environment or the changes in frequency. A prototype of an AMDN for usein a two-antenna system will be fabricated and experimentally characterized. Finally, advanced AMDN design concepts that are expected to offer additional capabilities besides matching and decoupling (e.g., beam/null steering, non-reciprocal radiation patterns, etc.) will also be investigated.Successful execution of this project is expected to facilitate the development of multi-functional HF systems with robust full-duplex operation capabilities. The ability to dynamically adapt to a changing antenna environment, perform beam steering, and perform multiple transmit and receive functions while maintaining a high transmit/receive isolation are among thecapabilities expected from such systems. Multi-functional systems possessing such capabilities are expected to be useful to a wide variety of applications of interest to the U.S. Navy ranging from electronic support and electronic attack to beyond-line-of-sight communications and over-the-horizon radar systems.DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2021
- Source ID
- N000142112452
Entities
People
- Nader Behdad
Organizations
- Office of Naval Research
- United States Navy
- University of Wisconsin System