Enhanced Magnetic Communications

Environmental factors can strongly attenuate electromagnetic waves, degrading communication distance, data rate, signal-to-noise ratio and reliability of RF systems. Magnetic near-fields are an attractive alternative to propagating electromagnetic wave communication because the former are not negatively impacted in environments that interfere with RF communication. Near-field magnetic communication (NFMC) has traditionally been realized through coil-to-coil inductive coupling. Because magnetic near-field strength decreases rapidly (1/r3) with increasing distance from the source, receive coils must contain many electrical turns, making communication over 100s of meters challenging. This Phase I program demonstrated a novel approach to NFMC by replacing the receive coil with a magnetostrictive/electroactive (ME) laminated receiver measuring typically 20 mm × 8 mm × 0.4 mm. The pT field at 140 m from a 46 cm diameter coil of 6 Ampere-turns was readily detected with the ME receiver. The Phase II effort will further develop the NFMC system by improving the internal properties of the ME receiver, designing sophisticated and power efficient transmit and receive electronics, and optimizing system efficiency. The Phase II prototype NFMC system will be wearable and provide soldiers with 2-way voice communication over many hundreds of meters and data transmissions (such as text) to distances over 1 km.