RFID tag for an object having metallic portions and method thereof

摘要

An RFID tag ( 20 ) has an electrically non-conductive substrate ( 22 ) with a mounting surface ( 24 ), an electrically conductive member ( 26 ), a conductive bridge ( 28 ), a dielectric strip ( 30 ), and a semiconductor device ( 32 ). The member ( 26 ) is mounted to the surface ( 24 ) and has an inner section ( 38 ), an outer section ( 40 ) and a connecting section ( 42 ). The section ( 38 ) has windings ( 44 ) and a free end ( 46 ) extending from one of the windings. The section ( 40 ) substantially surrounds the section ( 38 ) and has a winding ( 50 ) and a free end ( 52 ) that extends from a portion ( 54 ) of the winding ( 50 ) towards the section ( 38 ). A segment ( 56 ) of the section ( 42 ) is disposed between the ends ( 46, 52 ). The bridge ( 28 ) spans from the end ( 46 ) to the end ( 52 ). With the strip ( 30 ) disposed between the bridge ( 28 ) and the member ( 26 ), capacitive sections are thereby formed along the strip ( 30 ).