Wu Jingqi, Zeng Zilun, Wang Liwei, Xu Jianchun, Bi Ke
State Key Laboratory of Information Photonics and Optical Communications, School of Science, Beijing University of Posts and Telecommunications, Beijing, 100876, P. R. China.
Adv Sci (Weinh). 2025 Jan;12(3):e2408770. doi: 10.1002/advs.202408770. Epub 2024 Nov 28.
Very low frequency electromagnetic waves adeptly propagate in harsh cross-medium environments, surmounting the rapid attenuation that impedes high-frequency counterparts. Traditional low frequency antennas, however, encounter challenges concerning size, efficiency, and power. Here, an isolation transformer based very low frequency loop antenna with compact size and well impedance matching is proposed to enhance radiation characteristics for long-distance communication. By utilizing the high magnetic permeability amorphous/nanocrystalline alloy FeCuNbBSi, the isolation transformer enables efficient and stable high-current input. This design surpasses the current limitation of the conventional loop antennas, thereby improving its electromagnetic performance. Consequently, the radiation intensity of proposed antenna can be effectively increased over 30 times compared to traditional loop antennas. According to the experimental measurements, the transmission distance is over 340 m at 15 kHz using a single proposed antenna with a diameter of 2 m. Its robust performance, such as high radiation efficiency, low power consumption, and long-distance transmission capacity, suggests significant potential for applications in underground communications and underwater information transmission.
极低频电磁波能够在恶劣的交叉介质环境中顺利传播，克服了阻碍高频电磁波传播的快速衰减问题。然而，传统的低频天线在尺寸、效率和功率方面面临挑战。在此，提出了一种基于隔离变压器的极低频环形天线，其尺寸紧凑且具有良好的阻抗匹配，以增强长距离通信的辐射特性。通过利用高磁导率的非晶/纳米晶合金FeCuNbBSi，隔离变压器能够实现高效稳定的大电流输入。这种设计突破了传统环形天线的电流限制，从而改善了其电磁性能。因此，与传统环形天线相比，所提出天线的辐射强度可有效提高30倍以上。根据实验测量，使用单个直径为2米的所提出天线，在15kHz时传输距离超过340米。其高辐射效率、低功耗和长距离传输能力等强大性能表明，在地下通信和水下信息传输应用中具有巨大潜力。
