contactless chip cards, smart cards or so called transponder cards contain and transmit both the energy for the chip’s power supply and the information itself by using electromagnetic fields. This offers many advantages, such as warless cards and comfortable handling for the user. In general there are two main frequencies, low frequent transponders that use 125 kHz and high frequent transponders with 13.56 MHz

Card chips do not need an energy source of their own, need not be maintained and can be read within a distance of 0,7 m to the card acceptor device. It is possible to store different applications within the same card (e.g. access control and cafeteria).