In the area of the contactless identification you subdivide RFID transponder in two types: passive RFID transponder and active RFID transponder.
Passive RFID transponder do not need an own power supply, the receive their power supply from the high frequency field of the reading device through induction. In this case there are a bunch of advantages like complete freedom of maintenance therefore high endurance and low dimension.
Passive RFID transponder: they exists out of a silicon chip and another antenna. The same antenna is responsible for the data exchange between the reading device and the RFID transponder. There is no need for an own power supply which results in low dimensions and allows the assembly of passive RFID transponder in firm “cases”. Therefore objects or people can be equipped fast and uncomplicated with an electronic legible data medium. Common structure for RFID transponder tags are plastic cards, token coin shapes, key chains, glass tubes or bracelets. The possibility to capture machine-readable data of people or objects without any contact opens many new areas of application and eases the process of many industrial application. One of the special possibilities of rational capturing results in the special ability of reading a large amount of RFID transponders at once. The bulk detection makes it possible to capture a complete range of goods within a few seconds.
Active RFID Transponder: to enlarge the reading range the RFID transponder needs more energy, which it cannot get via antenna power exchange due to the existing restriction of the sending strength. That is where the RFID transponder gets a battery attached, which gives it the necessary sending power.
RFID transponder can be equipped with storage, serving as an external data storage, next to the branded unique serial number. This data base allows to store information without any connection of the device to a computer and retrieve them any time.