What is RFID?

What is the meaning of RFID?

Today, many still see RFID (acronym Radio Frequency IDentification) as a simple and straightforward replacement of the barcode technology. RFID is however a collective name for several technologies based on the same principle; data exchange using radio waves (frequencies).

RFID technologies explained

RFID is a a generic term for data exchange technologies (and in combination with other technologies) to automatically identify objects, products or assets and people. Essentially, it’s a technology that connects objects to the internet and other database systems, so they can be tracked, and individual users e.q. companies can share data about them. Here, The Internet-of-Things comes to mind.

RFID works on a the fundamental of having tags and readers; easily recognisable, for example, are payment or loyalty cards, access RFID cards or fobs, passport ID, RFID chips for animal identification. The most commonly used RFID tags/labels are passive and have no internal power supply such as an embedded battery. They are energised by the electromagnetic field conducted by the reader – some publishers refer to it as an interrogator or scanner.

The vast majority of RFID tags use a silicon microchip (RFID chip) to store a unique serial number and usually some additional information. There are two broad categories of RFID systems:

• Passive RFID tags do not have an internal power source, they simply reflect back energy (radio waves) coming from the reader antenna.
• Active RFID tags have their own transmitter and a power source, usually – but not always – a battery. They broadcast a signal to transmit the information stored on the microchip. A sub-group in the active RFID tags is the group of battery assisted tags that have a power source on board but act as a passive tag, mostly used to support embedded sensors in UHF RFID tags.

Subcategories of RFID

Passive RFID systems include: 

• Low Frequency (125kHz & 134.2kHz): animal identification, identification in car keys for demobilizing anti-theft systems (LF)
• High Frequency (13.56MHz): used in access control systems, biometric identification such as passports and payment systems (NFC)
• Ultra-High Frequency (860 – 960MHz): the RFID technology referred to in most publications, used in logistics and manufacturing environments (UHF)
• Microwave (2.45GHz): used in active RFID systems in combination with sensor technology and data logging on board.