Technology
Radio Frequency Identification
RFID is identification of objects with radio waves. The data saved in the tag memory is used for this purpose. Tags consist of two main elements: an integrated circuit (chip) and a transmitting and receiving antenna. The chip contains a memory from which we take data through a wireless transmission via the antenna.
The functions of reading and saving the data are made through a computer-controlled RFID reader. In passive tags (without their own power) the chip is powered by the RFID reader via the antenna. The tags can work at different frequencies and perform different functions (only reading, saving and reading, alarm functions or self-destruction). The tag memory capacity is also selected depending on applications. A maximum distance from which we can read the data is an important parameter for the correct working of the RFID tags. The system work frequency, antenna constructions in the tag and reader and the power of the reader influence this distance.
LF - Low Frequency (124-134 kHz)
Systems working at this frequency were the first and were universally applied. The tags are in the form of discs, plastic cards, and pastilles with a hand strap. Applications mostly include access control, time and attendance, sports facility entry systems (swimming pools, gyms, ski slopes). Car immobilisers are other applications. Animal identification is a completely different application. The lack of a universal standard, small reading range or the lack of possibility to read many tags at the same time are the disadvantages of this frequency range. Currently no intensive work is conducted on the development of this frequency range.
HF High Frequency (13.56 MHz)
Systems working at this frequency are more advanced than the systems working in the LF range. The conflict between tags was resolved, data transmission speed increased, bigger ranges of reading and saving the data were obtained. The ISO 15693 standard was also created which enables the compatibility of tags and readers of different manufacturers. The tags in the form of self-adhesive Smart Labels are most common. The system is used in tagging clothes, controlling the movement of air luggage, tagging books and documents (including passports or electronic student ID), in entry tickets for music and sports events. Applications in the control of the circulation of containers or trucks inside industry plants are also known.
UHF Ultra High Frequency (865-952 MHz)
This frequency ensures the biggest ranges of reading for passive tags (up to 6 m). The confilcts between labels are resolved and a global standard established. Despite the differences in the frequencies of the equipment work: 865 - 869 MHz Europe, 915 MHz USA and 952 MHz Japan, tags and readers were created which can work worldwide; thus they can cover a global supply chain. This frequency is commonly considered as optimal for logistic applications and the rate of development of the equipment working in this band is considered to be the biggest. EPC GEN 2 seems to be a standard which meets the conditions of the world standard.
UHF Ultra High Frequency (2.4 GHz)
The frequency is common using active tags Therefore, the reading range increased to 10 m. The data transmission speed enables the reading of data from quick moving objects (100 km/h), which failed previously. These features meant that the band became useful for the registration of cars moving on the motorway, management of a transport fleet or the registration of moving rail carriages.