On the Study of Radiated Leakage Suppression in Near-Field Measurement of kHz-Band Acoustic-Actuated Multiferroic Antennas

Acoustically actuated multiferroic antennas offer a significant advantage in terms of miniaturization. For multiferroic antennas operating in the kHz range, the near-field radiation is typically measured to assess directionality. However, the feeding structure introduced between the multiferroic antenna and the instrument may induce strong radiated leakage, which can compromise the accuracy of the measurement results. This letter conducts detailed analysis of the radiation leakage issue and presents the first evaluation of radiated leakage generated by the feedline in measurements for several laminated composite kHz multiferroic antennas. The results indicate that the radiated leakage even exceeds the radiation produced by magnetoelectric coupling of multiferroic antenna. A feeding structure is proposed to suppress radiation leakage by 17.58 dB and 16.62 dB in the case studies, respectively, thereby effectively mitigating its impact on measurement. The proposed method will serve as a valuable reference for near-field radiation measurement of kHz-range multiferroic antennas.