Fundamental study of smart IC card system using ultrasonic information transmission

In this study, we propose a new type of smart IC card using ultrasonic information transmission. Ultrasonic transmission is safe for the human body and does not cause malfunctioning of electronic equipments. In addition, information transmission using ultrasonic can prevent "skimming" to utilize ultrasonic characteristics that have a large attenuation in air and a sharp directivity. Our study deals with an experimental model system for preliminary development and the analysis of its results. To minimize the power consumption of the card, the system does not need carrier waves to transmit information from the card to the card-reader/writer (R/W), because base band signal is transmitted directly. For the results of the prototype experiment, a transmission speed of 115.2 kbps is obtained at less than 1 mm distance. The proposed ultrasonic IC card system can have various practical applications in which secret information is absolutely kept.