Radio-frequency identification (RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID tag consists of a tiny radio transponder; a radio receiver and transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits digital data, usually an identifying inventory number, back to the reader. This number can be used to inventory goods.
Types of RFID tags:
- Active tag = In active tag, they have their own power supply and for transmitting the signal back to the reader, they rely on their own power supply.
- Passive tag = They do not have their own power supply. So these passive tags rely on the radio waves coming from the RFID reader for the source of energy.
- Semi-passive tag = They used to have their own power supply but for transmitting the feedback signal back to the RFID Reader they used to rely on the signal coming from the RFID reader.
It is a form of wireless communication that incorporates the use of electromagnetic or electrostatic coupling in the radio frequency portion of the electromagnetic spectrum to uniquely identify an object, animal or person.
Use cases of RFID:
- INVENTORY MANAGEMENT
- RETAILS SALES
Working of RFID
Every RFID system consists of 3 components: Scanning antenna, Transceiver, Transponder. When the scanning antenna and transceiver are combined, they are referred to as an RFID reader or interrogator. The RFID reader is a network connected device that can be portable or permanently attached. It used Radio frequency waves to transmit signals that activate the tag. Once activated, the tag sends a wave back to the antenna where it is translated into data. The transponder is located in RFID tag.
Difference b/w bar-codes and RFID tags: –
- Bar-codes are not read & write outside the manufacturers, and because they are printed on the outside of the object, are limited in terms of reuse; whereas RFID tags are more better protected.
- RFID tags cost more than Bar-code.
- Bar-codes require a direct line of sight and close proximity than an RFID tag.