Wideband soft-magnetoelectric antennas for very-low and low-frequency communication applications

Mechanically soft magnetoelectric (ME) laminates based on Metglas/(PVDF-HFP)–BiFeO3 composites were fabricated and characterized for very-low frequency (VLF) and low-frequency (LF) communication applications. Direct ME characterization revealed wideband sensitivity of 2 × 104–4.3 × 104 V/T across the upper VLF band (15–30 kHz), peaking at 2.2 × 106 V/T at the 86.1 kHz resonance. Converse ME responses are on the order of 10−6 T/V in the VLF region, increasing to 3 × 10−4 T/V at resonance. Soft-ME antenna-to-antenna transmissions were demonstrated at ranges up to 30.2 m, yielding a received flux of 5.9 fT at 86.1 kHz. Reception of signals from the NPM, NLK, and NML VLF transmitters at distances up to 4205 km showed strong agreement with VLF propagation theory, with projected 3 dB SNR reception ranges greater than 8000 km. These results demonstrate that soft-ME laminates offer considerable promise for wideband communication and sensing applications in the VLF/LF spectra where size, weight, and power constraints are present.