Magnetic Pendulum Arrays for Efficient ULF Transmission
Abstract
The frequencies lying between 300 Hz to 3 kHz have been designated as Ultra Low Frequency (ULF) with corresponding wavelengths from 1000 Km to 100 Km. Although ULF has very low bandwidth it is very reliable, penetrating and difficult to jam which makes it a great choice for communication in underwater and underground environments. Small and portable ULF antennas within a diameter of 1 meter would operate under an electrical length on the order of 10−4 to 10−6 wavelengths in free space, making them very inefficient because of fundamental limits on radiation from electrically small antennas. To overcome this problem, Mechanical Antennas or ‘Mechtennas’ for Ultra Low Frequency Communications have been proposed recently. For efficient generation of ULF radiation, we propose a portable electromechanical system called a Magnetic Pendulum Array (MPA). A proof of concept demonstration of the system at 1.03 kHz is presented. The theory and experimental results demonstrate that such a system can achieve a significantly higher quality factor than conventional coils and thus order of magnitude higher transmission efficiency. The concept can be easily scaled to the ULF range of frequencies.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 13, 2019
- Source ID
- 10.1038/s41598-019-49341-4
Entities
People
- Adam Propst
- Foad Fereidoony
- Rui Zhu
- Rüştü Umut Tok
- Scott Bland
- Srinivas Prasad M N
- Yuanxun Ethan Wang
Organizations
- United States Department of Defense