Multiferroic Resonators and Antennas

“Experimental Validation of Multiferroic Antennas in GHz Frequency Range” explores the design, fabrication, and testing of multiferroic antennas for high-frequency applications. The study focuses on antennas resonating at approximately 3.5 GHz and 6 GHz, demonstrating that magnetoelastic materials, such as nickel, exhibit magnetically induced radiation. The results are compared with those of non-magnetoelastic materials like Permalloy, revealing differences in their dynamic responses to magnetic fields. The research highlights that the magnetoelastic behavior in the GHz range significantly differs from responses at lower frequencies, emphasizing the need for further investigation into magnetoelectric radiation mechanisms. These findings enhance our understanding of compact antenna designs for modern wireless systems. 

Researcher: Rui-Fu Xu (許瑞福)

“Modeling of Multiferroic Antennas in the Akhiezer Regime: Effects of Acoustic Resonator Excitation and Topology on Radiation” explores a two-dimensional closed-form model for GHz-range multiferroic antennas, which predicts the electrical and mode shape responses of film bulk acoustic resonators (FBAR) and solidly mounted resonators (SMR). It provides an analytical solution for the radiated electromagnetic field, enabling antenna optimization to maximize radiation power. The analysis demonstrates that FBAR-based antennas radiate more effectively than their SMR counterparts due to substrate energy loss, and that thickness-extensional modes outperform thickness-shear modes. Additionally, Akhiezer damping, rather than Chu's limit, primarily constrains antenna radiation efficiency at GHz frequencies. 

Researcher: Louis-Charles Ippet-Letembet (歐祿益)