Types of RFID-Transponders
Energetically, RFID transponders can be divided into three groups:
Passive RFID transponders
RFID - Passive Transponder
Passive RFID transponders receive their required energy completely via a magnetic or electromagnetic energy field of the RFID read-write device. Data can also be transmitted bidirectionally via this field. These passive RFID transponders are used mostly used.
+ Advantage: cheap, small size - Disadvantage: small range, small memory
RFID - Function of a Passive Transponder
Semi-Active RFID transponders
Semi-Active RFID transponders have their own operating energy source. This serves to supply the logic part (controller, memory). The high-frequency part, which is used for data transmission to the RFID read / write unit, is still obtained from the electromagnetic field.
RFID - Function of Semi-Active Transponder
Active RFID transponders
Active RFID transponders have their own operating energy source as well as their own transmitter. The electromagnetic field of the RFID read-write device is used exclusively for data transfer and no longer for additional energy transfer.
The transponder is normally in so-called "sleep mode" and is only activated by the RFID read-write unit when a data transfer is to take place. This can increase the service life of the transponder's battery up to several years.
RFID - Active Transponder
+ Advantages: lower electromagnetic field, increased range, lower latency (i.e. lower signal runtime), more functions
- Disadvantages: large, expensive
