Transceiving Signals by Mechanical Resonance: A Miniaturized Standalone Low Frequency (LF) Magnetoelectric Mechanical Antenna Pair With Integrated DC Magnetic Bias

Abstract

Low frequency(LF) communication systems offer significant potential in internet of things(IoT) applications due to their low propagation loss and long transmission range. However, traditional LF electrical antennas are too bulky for IoT. Due to their small dimensions, magnetoelectric mechanical antennas are promising, however, the state of art magnetoelectric antennas either have bulky external magnetic bias or have limited operation range. In this paper, we present a miniaturized standalone LF magnetoelectric transmitting/receiving antenna pair with integrated magnetic bias to significantly improve the operation range by 360%. As the operation principle of the antenna is based on mechanical resonance, its dimension is reduced by four orders of magnitude compared with an electrical antenna counterpart. The transmitting and receiving antennas are the same in structure and dimensions: they are both composed of magnetostrictive Terfenol-D and piezoelectric PZT laminate with dimensions of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$38\times 12\times19.4$ </tex-math></inline-formula> mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The integrated magnetic bias significantly reduces the dimension compared with magnetoelectric antennas with external bias. Performance measurement demonstrates that a maximum operation distance of 4 m is achieved without DC magnetic bias, while maximum operation distance with DC magnetic bias is 9 m, which is significantly improved by 225%. Compared with the spiral LF antenna presented in prior study, the radiation efficiency of the magnetoelectric antenna is enhanced by 17.96 times, resulting in 360% operation distance improvement from 2.5m at an input power of 4.5W to 9m at an input power of 2.03W. The LF magnetoelectric mechanical antenna pair may be a promising candidate for IoT applications.