Patent ID: 8816824

Claim:
A multi-field antenna configured to receive a signal over one field selected from a plurality of different fields of the antenna, the multi-field antenna comprising: a first magnetic loop; a first tuner to tune the first magnetic loop to provide a first volume field for reading data; a second magnetic loop; a second tuner to tune the second magnetic loop to provide a second volume field for reading data, the second volume field being smaller than the first volume field; a first metallic element configured to cover at least a portion of the second magnetic loop, the first metallic element creating a mask for the first magnetic loop from the second magnetic loop, the first metallic element comprising a slot extending along a length of the first metallic element from one end of the first metallic element to a point proximal an opposite end of the first metallic element, wherein the field area of the second volume field is defined, in part, based on the dimension of the slot; a switch to configure the first tuner and the second tuner to select the one field of the plurality of fields; and an interface to connect the multi-field antenna with a signal processing device operable to receive and process the signal.