A Fully Packed Magnetoelectric VLF Communication System Based on Self-Designed Circuits and Wireless Transmission Into a Metallic Enclosure

Magnetoelectric (ME) antennas have offered significant advantages in the design of very-low-frequency (VLF) communication systems operating in challenging environments such as underground, underwater, and inside metallic enclosures. However, state-of-the-art ME-based communication systems either depend on bulky commercial signal processing instruments or have limited reports on digital signal transmissions. In this work, we demonstrate a compact design of an ME VLF communication system based on self-designed modulator and demodulator circuits, working at the electromechanical resonance (EMR) frequency of the ME antenna and having a remarkably reduced size for greater applicability in realistic industrial scenarios. The concept of sending Morse code through amplitude-shift-keying (ASK) modulation was confirmed in the proposed ME VLF communication system. Our findings revealed that the maximum communication distance can be considered as 5.7 m when the bit error rate (BER) is limited to $10^{-2}$ . Furthermore, VLF wireless signal transfer through a harsh environment (metal box) was verified with our communication system. An effective communication distance of 0.85 m could be realized when placing the ME receiver in a 5-mm iron box, demonstrating the ability of the wireless signal to penetrate conductive media. The proposed fully packed ME VLF communication system provides advantageous alternative for underground, underwater, and inside-metal-container communications.