Optimization on the driving frequency for a magnetoelectric antenna under continuous operation

Magnetoelectric (ME) mechanical antennas have been providing a promising route for portable and efficient very-low-frequency (VLF) communication. An ME antenna is usually considered a time-invariant system in current studies, and the performance evolution under continuous operation is rarely focused on. In this study, we reveal the temperature-induced, time-variant characteristics of a VLF ME antenna by investigating the heat exchange between the ME antenna and the ambient environment. A feedback loop is then established to capture the dynamic characteristics of an ME antenna under continuous operation and to instruct the optimization about the driving condition for enhanced magnetic field emitting performance. Finally, it is experimentally validated that exciting the ME antenna at our optimized driving frequency enables a 38.4% enhancement in produced magnetic flux density compared to the conventional excitation method. This work is believed to accelerate the application of ME antennas.