A Ultraminiature Through-the-Earth Communication Antenna Using Rotating Permanent Magnet

This paper presents the development and experimental testing of a miniaturized low-frequency antenna for ground-penetrating communication. The study focuses on a cylindrical NdFeB permanent magnet actuated by an electric motor for signal transmission. Frequency-shift-keying modulated signals are transmitted, and reception is achieved using a fluxgate sensor. Signal processing techniques, including DC removal, filtering, and demodulation, are applied to extract transmitted information. Field testing demonstrated successful groundpenetrating communication over a 20-meter distance between two wells. In conclusion, the developed miniaturized low-frequency antenna showcases its potential for or reliable underground communication.