Inductive communication system and method

Abstract

A system and method communicate signals between a portable unit and a communications system. The portable device communicates with a base unit using inductive coupling. The base unit is further connected to a wider communication system such as a telephone network. Multiple, orthogonally arranged transducers are used in the base unit to provide a more complete magnetic field and to prevent mutual inductance nulls which are otherwise present in a magnetic field. The use of short-range inductive coupling minimizes the power requirements and limits interference with other sources. The inductive coupling may also be used to recharge a battery in the portable device.

What is claimed is:  
     
         1 . A method of communicating information over a wireless link, the method comprising: 
 sensing a first magnetic field signal on each of at least two transducer elements;    providing a transmit signal to be transmitted; and    selectively applying the transmit signal to one or more of the at least two transducer elements in accordance with a relative strength of the sensed first magnetic field signal to transmit a second magnetic field signal.    
     
     
         2 . A system for communicating information over a wireless link, the system comprising: 
 a first station including at least two inductive transducer elements to receive a magnetic field from a second station, the first station including a circuit to detect a signal strength of the magnetic field as received on each of the at least two transducer elements, the first station selectively applying a transmit signal to the at least two inductive transducer elements in accordance with the detected signal strength of the magnetic field to transmit to the second station.