Radio Frequency Identification
WHAT IS RFID TECHNOLOGY?
The RFID technology allows unique identification, remote and wireless, of things or persons, thanks to the radiofrequency.
RFID systems are composed primarily of two basic components: the transponders (commonly called TAG) and the READER with antennas.
The RFID trasponders (TAG), are simple devices with a microchip with a non-volatile memory and an antenna, capable of interacting with certain electromagnetic / electrical frequencies generated by special READER and ANTENNAS. The RFID tags are divided mainly in ACTIVE RFID TAG (powered by batteries) and PASSIVE RFID TAG (without power supply batteries).
The PASSIVE types are the most common and cheap tags which through their integrated antenna, capture the energy required to activate themselves and transmit / exchange data with the Reader that generates the electric / magnetic field necessary. There are hundreds of types of passive RFID TAG, the simplest are similar to adhesive labels called “smart labels” .
READER AND ANTENNAS
The RFID readers are electronic devices capable of generating specific frequencies that are propagated in the air through special antennas. On the market there are various types of readers and antennas, that can be divided into three main categories:
- Desktop readers: smaller and cheaper products, generally connected to the USB port of a PC. The power is usually limited to reading / writing of individual tags in a quick and economic way.
- Portable reader (Handheld): compact products of various shapes, with different complexity and costs. There are economical products that can be connected to the USB ports of a PC and very complex products (mini-computers powered by batteries) that can simultaneously manage RFID readings, barcode, QR code etc. and with screens can be connected in WIFI, Bluetooth and GPRS. in the UHF field these readers has reading performance limited by the size, than fixed readers.
- Fixed readers: products used for industrial uses, normally permanently fixed. There are built-in reader antennas or individual reader connected to a wide range of antennas, that can ensure the highest possible performance, especially for massive readings.The overall performance of an RFID reading system always depend on the appropriate mix of the three components: readers, antennas and the Tags used.
They are mainly divided into four different categories, characterized by advantages and disadvantages.
MAIN PASSIVE RFID TECHNOLOGY
TAG LF Freq. 125 e 134,2 KHz (Low Frequency)
Worldwide frequency. Typical reading range: very close contact. Typical applications: electronic keys for access control and burglar alarms, animal identification, credit cards etc. Reading distance: 1-3 CM.
Reading little disturbed by metals and liquids, unique code (UID) pre-attached.
Very close contact reading, usually rigid products.
TAG HF Freq. 13,56 MHz (High Frequency)
Standardized by the ISO 14443 and ISO 15693 worldwide. Typical reading range: up to 2-30 cm. Typical applications: Skipass, credit cards, access control, industrial identification etc. Reading distance: 3-120 CM.
Mature and widespread technology, unique code (UID) already programmed and unchangeable, many of the market available tag types with high safety standards.
Very close contact reading hampered by metals and liquids, quite expensive readers.
TAG NFC Freq. 13,56 MHz (Near Field Communication)
Standardized by the ISO 14443A. Typical reading range: just few cm. Typical applications: micropayments, geolocation with smartphone, etc. Reading distance: 1-5 CM.
Technology found in most Smartphone (reader and antennas) , a variety of possible uses and universal. Available chip with high user memory and different safety levels.
Close contact reading, disturbed by metals and liquids.
TAG UHF EU Freq. 868-915 MHz (Ultra High Frequency)
Frequencies variable in the individual countries of the world. Typical reading range: up to 10/15 mt. Typical applications: logistics asset, remote control access, industrial asset etc.
Remote readings at high distance (10-15 mt), rapid massive reading, wide choice of tag types available on the market.
Reading very disturbed by metals, liquidis and magnetic fields. high costs of the readers.