A radio operated data card whose outer jacket forms a sealed protected housing for internal electrical components, including an RFID integrated circuit which incorporates data storage and a radio frequency transceiver, and one or more on-card antenna structures. Manually operated electrical switching...http://www.google.com/patents/US20040124248?utm_source=gb-gplus-sharePatent US20040124248 - Methods and apparatus for wireless RFID cardholder signature and data entry
