Enhanced near-field radiation of acoustic-actuated antennas using embedded magnetoelectric composites

Abstract

Acoustic-actuated antennas operate at the acoustic wave resonance rather than electromagnetic (EM) wave resonance and thus show a significant superiority for the miniaturization of antennas. This paper designs a new acoustic-actuated antenna using embedded magnetoelectric (ME) composites, to improve the radiations of ME antennas through the enhanced strain transfer at the interfaces between different phases. The performance of the ME antenna is examined through a multiphysics finite element method with considering the nonlinear magnetostrictive model. Then, three optimum schemes are proposed for the improvement of the ME antenna, which are also verified by the simulation results. It has been demonstrated that the EM radiations of the embedded ME composite are effectively improved by changing its sizes or configuration. Due to the magnetic flux and stress concentration effects, the maximum |E| and |H| radiations are respectively enhanced by 88 % and 97 % via using a trapezoidal magnetostrictive layer. The effects of magnetic bias and pre-stress indicate that near-field radiations of the ME antennas with fixed dimensions can be enhanced by external multi-physics fields. This simulation may facilitate the understanding of nonlinear CME behavior as well as provide a basis for the design of tunable ME antennas.