Phase Alignment for Coherent Distributed Arrays
Abstract
ABSTRACT: Sustaining the military advantages currently enjoyed by the United States Navy will depend in part on the ability to quickly and cheaply improve the performance of electronic warfare (EW) systems. Coherent networked EW systems have the potential to acco"mplish significant improvements in EW capability without the need to develop new individual systems. Inparticular, coordinating sep"arate wireless systems to create a coherent distributed array (CDA) can yield dramatic gains that cannot feasibly be achieved on a s"ingle platform, or with noncoherent coordination on multiple platforms. These benefits include transmit power gains proportional to"" the number of platforms squared, significant spatial diversity affording robustness, and the ability to directly scale capabilities"" by simply adding or removing nodes in the array [1-3]. The ultimate level of flexibility is achieved in an open-loop array, where t"he nodes self-align without using feedback from the target location. Open-loop CDAs are critically important for future EW systems b"ecause they enable the full range of EW techniques to be deployed, including transmit techniques that do not require signal input fr""om the target. Furthermore, because capabilities scale by adding nodes to the array, significant improvements can be achieved with r"elatively low cost increases. Open-loop CDAs thus represent a radicallydifferent approach to future system development that can achieve greater operational gains at lower overall cost. The challenges involved in implementing coherent distributed EW systems are si"gnificant, and principally involve the ability to wirelessly lock the frequencies of separated oscillators on each EW node. The PI h"as previously led efforts developing and demonstrating critical technologies enabling fully open-loop coherent distributed transmiss"ion, proving the feasibility of achieving and maintaining sufficient phase stability between separate platforms. In one prior effort"", a high accuracy microwave ranging technique achieved sub-mm range accuracy and was used to experimentally demonstrate the first op""en-loop coherent distributed transmission. A follow-on effort developed a novel one-way wireless frequency locking approach, which w"as used to demonstrate the first fully wireless open-loop CDA. This effort seeks to explore the fundamental challenges and capabilities of open-loop coherentdistributed EW systems with operationally relevant node separations and environments. Through the developm"ent of a software-defined radio (SDR) hardware platform, high-accuracy ranging and high-precision frequency transfer techniques will" be implemented and tested over long ranges and various weather conditions. The goal is to explore the capabilities of wireless phas"e locking methods, determine their fundamental limitations, investigate the effects of environment and weather, and research the abi"lity to scale the techniques to longer ranges and larger arrays. The results of this effort will inform future networked EW research and development efforts bydefining critical challenges and hardware requirements for coherent and non-coherent networked EW operation.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 29, 2017
- Source ID
- N000141712886
Entities
People
- Jeffrey A. Nanzer
Organizations
- Michigan State University
- Office of Naval Research
- United States Navy