Coil the intelligent IC card to have what use?

Every piece of non touch type IC card (card) of the implanted coil inside, sothe IC card coil have what use? In fact, the IC card coil is equivalent to theantenna to receive TV signals, but the IC card coil is used to signal receivingIC card reader to send out, but also be able to send signals to the IC card reader, and then the realization of information and data exchange and communication. Often the size of the area affected coil distance induction IC card.

IC card is the card coils along four edges of the spread, the range card edgearound 3-5mm distance, is a rectangular overall; while the ID card coil scatter diagram for a perfect circle, it is generally in the card center, or on the left, orright; so we can from the coil shape to admit the IC card and ID card.