A High-Q Magnetoelectric Transmitter Realized by Full-Chain Loss Reduction in Electro-Mechanical-Magneto Conversions for Efficient Radiation

Magnetoelectric (ME) transmitters typically have efficiency bounded by combinational contributions from each stage involved in the full-chain cascaded electro-mechanical-magneto energy conversions, this makes it challenging to reduce each stage of the full-chain mechanical losses simultaneously to obtain the efficient radiation enhancement without consuming much power. To address this issue, a high-Q ME transmitter consisting of FeNi-based ferromagnetic alloy and piezoelectric ceramic was modelled, fabricated and systemically characterized. Full-chain efficient electro-mechanical-magneto conversion involved in the ME transmitter facilitates long-distance radiation and low power consumption at cm scale. Results show that Q value of the ME transmitter was estimated to be 607 by ring-down period of 11ms, which matched well with value obtained from frequency domain. Furthermore, an optical non-contact measurement system was established to examine the vibration velocity and induced voltage responses simultaneously, revealing that the ultra-low mechanical-magneto losses are responsible for efficient electromagnetic (EM) radiation. Moreover, a magnetic radiation field of 52.5nT@1m was achieved in saline-air cross-medium communication with high efficiency of 8.37×10^-12 under lower input power of 120mW, exhibiting approximately 13200× greater radiation enhancement compared with an electric dipole antenna under same physical size. This innovation represents a breakthrough in balancing the trade-offs between miniaturization and efficiency, offering great promising applications in unidirectional instruction transmission of AUVs/UUVs, underground/underwater navigation and timing and energy transmission /wireless sensing liberated without requirements of high bandwidth.