Abstract: A thin and flat integrated circuit assembly (10, 40) may be achieved by using a thin carrier (20) with shallow cavities (22, 24) for holding the integrated circuits (16) and/or discrete circuit components (14). The integrated circuits (16) and/or circuit components (14) may be friction fitted in the cavities (22, 24) or they may be secured therein by the use of adhesives and/or solder. Electrical connection between the integrated circuits (16) and circuit components (14) may be done with wire bonding, ribbon bonding, tape-automated bonding, lead frames, flip chip bonding, and/or conductive gluing of leads. The circuit assembly may then be accommodated into a credit card-sized packaging with standard dimensions set by the International Standards Organization.

Abstract: An HF antenna comprising a sheet-like, flexible multipart magnet core (16) manufactured of ferromagnetic material is provided with an antenna winding which is made up of a plurality of turns and surrounds the magnet core (16). The turns of the antenna winding are formed by printed wiring (12a and 12b) arranged on a flexible film (10a and 10b) surrounding the magnet core (16).

Abstract: Apparatus and method of identifying a plurality of transponders (10-16) entering into an inquiry field (18) of an interrogation unit (20) are provided. The transponders (10-16) are each assigned a unique identification code. Upon receipt of an interrogation pulse from the interrogation unit (20), each transponder (10-16) responds with its respective identification code. Depending on the spatial distance of each transponder (10-16) with respect to the interrogation unit (20), the interrogation unit (20) detects and receives the strongest response. The received identification code is stored. The interrogation unit (20) repeatedly sends interrogation pulses containing any stored identification code until all of the transponders (10-16) are identified and read.

Abstract: A thin and flat integrated circuit assembly (10, 40) may be achieved by using a thin carrier (20) with shallow cavities (22, 24) for holding the integrated circuits (16) and/or discrete circuit components (14). The integrated circuits (16) and/or circuit components (14) may be friction fitted in the cavities (22, 24) or they may be secured therein by the use of adhesives and/or solder. Electrical connection between the integrated circuits (16) and circuit components (14) may be done with wire bonding, ribbon bonding, tape-automated bonding, lead frames, flip chip bonding, and/or conductive gluing of leads. The circuit assembly may then be accommodated into a credit card-sized packaging with standard dimensions set by the International Standards Organization.

Abstract: Apparatus and method for identifying a plurality of transponders (10-16) located within an inquiry field (18) of an interrogation unit (20) are provided. Each transponder (10-16) is assigned an unique identification code, and the interrogation unit (20) dynamically constructs and modifies a bit string used to solicit responses from selected transponder(s) until each transponder (10-16) in the inquiry field (18) is identified. The bit string is transmitted to the transponders, which compares it with the least significant bits of their respective identification codes. A mismatch between the identification code and the bit string results in suppressing the response from the transponder.

Abstract: An antenna comprising a sheet-like, flexible multipart magnetic core (16) manufactured of ferromagnetic material is provided with an antenna winding which is made up of a plurality of turns and surrounds the magnet core (16). The turns of the antenna winding are formed by printed wiring (12a and 12b) arranged on a flexible film (10a and 10b) surrounding the magnet core (16).