What is RFID and how does it work? Why is this a revolutionary technology?
We asked Paolo Nepa, lecturer at the Department of Information Engineering at University of Pisa.
Interview with Paolo Nepa, University of Pisa – First part
What is RFID?
The acronym RFID stands for radio-frequency identification system, that is, we have a transmitter that emits an signal via radio waves that is received by a tag. This tag contains a simple antenna and chip on which a serial number is stored that uniquely identifies the object the tag is attached to.
It is basically the equivalent of a barcode, where radio waves are used rather than an optical reading. Consider a hundred bottles on a shelf. They apparently all look the same, but the RFID tag allows us to discriminate one bottle from another because the bottles are actually not all the same.
Why choosing RFID?
RFID technology is revolutionary because the use of electromagnetic waves as an alternative to optical reading provides a number of advantages, such as remote reading. I can read a tag with a reader even at a distance of several metres.
I can read tags entirely automatically. Consider an opening through which tagged products pass, or people passing through a gate to attend an event with tickets that contain RFID tags.
Another advantage is the low cost. Most tags are passive, that is, they have no battery, and a passive RFID tag can now be purchased for less than 10 cents.
Another great advantage is certainly that a line of sight is not necessary.
For instance, I can read what is inside a box without having to open it, because electromagnetic waves can pass through materials with a low conductivity. Likewise, this technology is widely used in library management because I can read a tag even when it is hidden inside a book.
Is this technology dangerous?
People often ask me if RFID technology is dangerous. I would say absolutely not, because as far as tags are concerned, most of them — the most popular ones — are battery-free, so they are basically a piece of metal and cannot radiate at all.
As far as transmitters are concerned, they clearly have to transmit a radio-frequency signal, but as with all devices that use radio waves, there are international regulations that set limits to the maximum power that can be used. Manufacturers of RFID transmitters must comply with these limits to certify their products and sell them, just as with mobile phones or the Wi-Fi routers we have at home.
