Theoretical analysis on radiation performance of magnetoelectric antennas considering eddy-current loss and quasistatic hysteresis effect

Abstract

This paper proposes a theoretical model for the electromagnetic (EM) radiation of magnetoelectric (ME) antennas, considering the eddy current (EC) loss and the quasistatic hysteresis effect. It characterizes the loss characteristics with complex equivalent parameters and innovatively embeds the coupling of classical and anomalous EC losses into the equivalent permeability of the magnetostrictive layer, thus establishing a quantitative link between the EC loss and radiation performance of the ME antennas. The nonlinear quasistatic hysteresis constitutive equation is incorporated into the derived equivalent parameter through the equivalent parameter method. The developed theoretical model of EM radiation is highlighted with a direct comparison with experimental and simulation data that shows their close agreement. The results indicate that the EC loss significantly suppresses the performance of the ME antennas, causing frequency shift, phase angle lag, and performance degradation, while reducing the thickness of the magnetostrictive layer can effectively decrease the internal EC loss of the ME antennas, thus improving their matching and radiation performance. In addition, the influence of the magneto-elastic coupling characteristics and the EC loss effect of the magnetostrictive thin film on the hysteresis behavior is also revealed. The study provides a theoretical foundation for designing the high-performance self-biased ME antennas.