This is the second part of the article series Introduction to RFID technology, the basics of RFID explained by the Tech Geek.
The aim of this series is to dive into the House of RFID
archives and to present some of our earlier researches. The first
Introduction to Retail RFID Technology, part 1 discussed RFID
in general. This time we take a look at radio technology and radio
waves as they are an important element in RFID technology.
RFID is based on radio technology. This means that the
information is transferred through radio waves. In his book "RFID
Implementation", Dennis E. Brown (2007) describes a radio wave
"A wave is a disturbance that carries energy
from one place to another. Radio waves are created when electrons
are passed through a conductor, like an electrical wire. The
current creates a magnetic field. Fluctuations in the current
produce changes in the magnetic field, creating waves of
electromagnetic energy. These are called electromagnetic
Radio waves, more specifically, are low-frequency
electromagnetic waves. They oscillate more slowly, and their wave
lengths are longer than of other types of electromagnetic waves.
Oscillation refers to the waves repeatedly rising in the intensity
to a peak, fading a minimum, and then rising to their peak level
again. The complete path from one peak to the next one forms a
cycle, which refers to the oscillation rate of the wave: the number
of cycles that happen in the time of one second. (Brown 2007)
RFID technology operates mostly on four different
frequency levels: low frequency (LF), high frequency (HF),
ultra-high frequency (UHF) and microwave (MF). Besides the
operating frequencies, the most crucial difference between the
frequencies is the maximum reading distance. The higher the
operating frequencies, the longer the maximum reading
distance. Roughly, on LF the reading distance is a few centimeters
and on UHF several meters. The table below presents the frequencies
and some of their application areas.
LF technology operates between 30kHz and 300kHz.
LF is typically used in animal tracking: domestic animals and pets
carry their own RFID tags enabling to identifying them if needed.
Also the majority of bus cards nowadays have an LF RFID tag: the
floods of passengers move smoothly when each passenger's trip is
registered with a simple sweep of a card. LF technology is also
used in access control: the more users a school, a company premises
or an institution has, the more probable it is that the people
entering the premises must have their own RFID tag equipped "key".
With these kinds of solutions each individual person entering the
premises can be tracked, and if something gets stolen or damaged,
the last people entering the specific area can be identified. Car
immobilizers are also one use area: nowadays stealing a car by
starting it "from wires" is quite challenging since the newer cars
will not start up the engine unless the proper key is inserted.
Also, one of the rising application areas of LF is the NFC
technology. It has been acting as a remarkable tool in enhancing
HF operates between 3MHz and 30MHz. Libraries and
archives use RFID readers operating on this frequency. HF tagging
is used also in laundries and in shipping parcels. And
last but not least: airports put HF RFID tags
on luggage in order to improve the luggage handling,
enhance faster operations in re-routing and generally
make sure that a bag is in the same airplane
as the right passenger. Simply, the HF application
area is roughly the same as in the LF technology with some
exceptions, such as animal tagging is only for LF technology.
A common application for HF is NFC (Near Field
Communication). The NFC allows smartphones and other enabled
devices to communicate with other devices, which
contain an NFC tag. NFC can be used for example
in paying at the cash register, or reading product
information. Also opening a door lock via NFC is possible.
UHF operating frequencies are between 300 MHz and
3 GHz, and most of the new commercial applications
have been created on UHF. These consist of retail applications,
asset management and supply chain logistics, for instance.
created the standards around the frequencies. Already 78 countries
(96,5% of the global gross domestic product (GDP)) have regulations
in place or will be in place shortly. In 3 countries (1% of
the global (GDP)) regulations are in process, and in 43 countries
(2,5% of the global (GDP)) information is not yet available.
What is worth noting is the fact that all the
countries and continents do not use the same UHF frequency ranges.
Therefore, when moving from one continent to another the
differences in the frequency ranges are so remarkable that
necessarily the same devices are not able to operate on different
continents. Therefore, it is important to inform the manufacturer
of readers about the continent (or country) where the devices are
used in future.
In our next article, the Tech Geek discusses
different types of tags. Stay tuned for part 3!
Brown, Dennis E. (2007) RFID Implementation. McGraw-Hill