Magneto-Mechanical Transmitters for Ultralow Frequency Near-Field Data Transfer

Electromagnetic signals in the ultralow frequency (ULF) range below 3 kHz are well suited for underwater and underground wireless communication thanks to low signal attenuation high penetration depth. However, it is challenging design ULF transmitters that simultaneously compact energy efficient using traditional approaches, e.g., coils or dipole antennas. Recent works have considered magneto-mechanical alternatives, which magnetic fields generated motion of permanent magnets, since they enable extremely can operate with consumption suitable human-portable applications. Here we explore operating principles resonant (MMT) over frequencies spanning a few 10 s Hz up 1 kHz. We experimentally demonstrate two types MMT designs both single-rotor multirotor architectures. study nonlinear electro-mechanical dynamics MMTs point approximation magneto-static simulations. further techniques control operation amplitude modulation bits-per-second. additionally how oppositely polarized modules permit systems dc-field but do not sacrifice ac field produced.