ANTENNA FOR USE WITH AN AUDIO INDUCTION COMMUNICATION SYSTEM

摘要

An antenna for use with an audio induction communication system provides a communication field of substantially uniform strength at all points within a given pick-up zone along which receiver-equipped persons are expected to travel or within which such persons are expected to stand while receiving a message through their receivers. The antenna comprises a continuous wire located in the vicinity of the pick-up zone and preferably buried beneath the surface of the earth defining the pick-up zone. The wire is disposed in a plurality of loops each of which loops includes two portions crossing the zone at two different points, such zone-crossing loop portions being arranged so as to include a spaced series of such portions located along the length of the zone and through which the exciting current passes in the same direction, those zone-crossing loop portions through which the exciting current passes in the opposite direction being closely grouped together at one end of the zone.