Method for backfield reduction in electronic article surveillance (eas) systems

An electronic article surveillance (EAS) system having at least two transceiver pedestals defining a detection zone between the pedestals, comprising:

• first and second pedestals, each including at least one exciter coil;
• a transmitter configured to generate exciter signals which, when applied to at least one of said exciter coils, produce response signals from tags present in the detection zone;
• at least one receiver configured to receive said response signals;
• and
• at least one processor configured to
• determine a tag response received at said first pedestal and at said second pedestal to obtain contemporaneous first and second tag responses, the first and second tag responses respectively associated with the first and second pedestals;
• compare the first and second tag responses to evaluate their relative signal strength and thereby determine a lesser signal strength tag response;
• set a reduced level exciter drive signal for a selected one of the first and second pedestals associated with a lesser signal strength tag response;
• cause the reduced level exciter drive signal to be applied to said at least one exciter coil at the pedestal associated with the lesser signal strength tag response to produce an electromagnetic exciter field in said detection zone;
• monitor an output of said at least one receiver to determine the occurrence of a third tag response resulting from the reduced level exciter signal;
• and
• determine the approximate location of the tag in relation to the first and second pedestals based on the first, second, and third tag responses, wherein said reduced level exciter drive signal is reduced in power level by said processor as compared to an exciter signal used to obtain said contemporaneous first and second tag responses.