RFID (Radio Frequency Identification) is a strategic technology designed for industries involved in distribution and manufacturing. Currently, this technology is also gaining importance in other sectors. In short, RFID is a technology that replaces barcodes with a microchip from which information can be read without seeing it. However, RFID is much more than just the next generation of barcode technology.
Most of us use RFID technology every day without even realizing it. When driving a car, haven’t we used an electronic device to pay highway tolls? Don’t we use some kind of ID badge to enter our workplace? These are examples of the widespread use of RFID technology.
RFID operating principles
RFID tags work by emitting electronic signals – either actively from their transmitter or passively, that is, by waiting for signals sent from an RFID reader and responding to them.
Passive RFID tags can be read-only or read/write, with the ability to update stored information using RFID readers. Readers can be mounted on standard portable devices. Currently, the memory area on passive read/write tags is about 2 kB, which allows for storing only small amounts of information. However, it is expected that as technology develops, the memory area available on the tag will increase.
RFID tags are available in a wide range of signal frequencies. Low-frequency tags operate in the frequency range from 30 to 300 kHz, and Ultra-High Frequency (UHF) tags in the range from 300 MHz to 3 GHz. The latter transmit information faster and further than low-frequency tags. However, they are more expensive because they consume more power, and the signals they transmit are subject to certain limitations when placed on objects containing water or metal. Information stored on passive tags can be read from a distance of about 30 cm for low-frequency tags, up to almost 1 meter for high-frequency tags, and up to 3 – 6 meters for Ultra-High Frequency (UHF) tags.
Higher frequency signals can operate over longer distances, but they do not pass through various substances as easily and require a clear line of sight (or at least a direct line of sight). For this reason, readers operating at higher frequencies have more trouble reading tags if there are obstacles in the signal path.