New Way of Generating Electromagnetic Waves

Abstract

This article presents a new method for generating low-frequency electromagnetic waves for navigation and communication in challenging environments, such as underwater and underground. The key concept is to disturb the magnetic energy stored around a permanent magnet in a time-variant fashion. The magnetic reluctance of the medium around the permanent magnet is modulated to alter the magnetic flux intensity and direction (disturb the stored energy) in order to achieve this goal. The nonlinear properties of the surrounding magnetic material are a critical phenomenon for efficient and effective modulation. Since the proposed way of generating the electromagnetic field is not based on a second-order system (resonant structure), the bandwidth of any modulation schema is not limited to the overall system quality factor. A transmitter is prototyped as a proof of concept, and the generated field is measured. Compared with the rotating magnet, the prototyped transmitter can modulate up to 50% of the permanent magnet’s stored energy with much lower power consumption.