Polarization control of bulk acoustic wave-mediated multiferroic antennas based on thickness shear modes

A novel electrically-small bulk acoustic wave (BAW)-mediated multiferroic antenna is proposed based on transverse shear waves instead of the longitudinal ones used in the previously proposed multiferroic antenna [1]. Two in-plane orthogonal pairs of electrodes provide independent excitation of the orthogonal transverse shear modes, enabling the first investigation of polarization control in a BAW-mediated multiferroic antenna. Using this approach, polarization can be controlled simply by adjusting the phase difference between the input RF signals of the two electrode pairs. The proposed design concept is verified numerically via COMSOL simulations and a series of post-processing steps in MATLAB. By assuming ideal input RF signals with equal amplitude and 90° phase difference, broadband circularly polarized radiation is achieved in the sub-GHz band.