A Contactless Read Write Transponder using Low Power EEPROM techniques

Historically used in radar applications to distinguish between enemy and friendly aircraft the concept of radio frequency identification evolved into a very different application in the early 1980´s for identifying pigs. Not surprisingly, these transponders became popularly known as pig tags and again, further evolution is leading to many different, and, on first examination, unusual applications. One, which perhaps gives an idea of the future is an application used to tag the thirteen thousand participants of the 1995 Berlin Marathon, to track, amongst other things, finishing position and time. A further technological enhancement to the tag has been the incorporation of a very low power non-volatile memory that can be written to and erased many times over. This paper describes the architecture, systems principle and implementation of a tag in the form of a single integrated circuit implemented in EM Microelectronic´s 2¿m, low-power CMOS technology; and, which allows contactless identification, where, the user can alter the identification code many number of times. Because of the very low power consumption the results showed a writing distance almost equal to the reading distance.