Article published Interface
Contactless cards go into overdrive
As part of the European project Onom@topic, CEA LETI demonstrated the feasibility of a contactless, very high speed interface (5.1 Mbits/s instead of the current 424 kbits/s).
In the same way as the future European citizen card, most official identity documents will, in years to come, be contactless cards. To be able to exchange ever-increasing volumes of data, without increasing the transfer time, LETI has been working on a very high speed contactless interface. Developed as part of the European Onom@topic European project, it results in a factor 10 gain compared with the state-of-the-art (standard electronic passport at 424 kb/s).
"So that the remote power feeding capacity of the card is not reduced during the transaction, we had to find a compromise between the quality factor of the antenna and the passband," explains Elisabeth Crochon.
The proposed solution is based on a multi-phase modulation used to increase the number of bits per symbol, which in turn increases the quantity of information exchanges in a given time period without having a detrimental effect on the channel passband. The speed thus obtained reaches 5.1 Mbits/s from the reader to the card (phase modulation on the carrier at 13.56 MHz) and 3.4 Mbits/s in the other direction (phase modulation on a sub-carrier at 1.7 MHz). Work remains to change international standards governing the contactless field, and LETI researchers are currently working towards this goal as they are involved in Aynor standard commissions.
