Page 28 - Logistics News Sept / Oct 2018

UHF RFID Technology

Passive RFID using UHF delivers

long-range benefi ts in the IoT

Courtesy www.rfidsolutionsonline.com

For consumers, the impact of the Internet of Things (IoT) may be summarised
as greater convenience. We have grown to expect certain things to happen
‘automatically’, without knowing how, and the IoT will accelerate and expand that.

FOR EXAMPLE, many people now use contactless Standards organisations are actively developing
payment, something that is enabled by short- the standards necessary to make RFID more widely
range RF communications between a payment deployable, which includes ISO and IEC as well as
terminal and a bank card, mobile phone or smart EPC Global; in 2009, ISO/IEC integrated UHF EPC
watch equipped with the same technology. This Gen 2 into ISO 18000-6 as Mode C.
avoids the need to physically insert a card into the The most important characteristic in RFID
payment terminal and enter a PIN. system performance is range, or the maximum
RF technology has the potential to change distance over which an RFID reader can either
many more aspects of modern life. One of the read information from, or write information
most established forms of RF communication used to, the tag. Tag range is defi ned in terms of
in the IoT is radio-frequency identifi cation (RFID) a successful read/write rate, expressed as a
technology, and research shows that its adoption percentage. The rate will vary with distance, but it
amongst retailers to tag clothing is set to increase also depends on the RFID reader’s characteristics
massively before the end of the century. and how the operating environment aff ects the
RFID technology has been around for many propagation of the signal.
years and its use in the IoT is entirely synergistic. In general, read and write ranges are diff erent
Because each RFID device has a unique identity, it due to the diff erent amounts of power required by
can be used to identify practically anything. When the transponder chip for each of these operations.
the reader is part of a connected system, it enables The main challenges involved with developing
almost unlimited potential for new applications. and operating a UHF RFID system reside in the
Recently, the introduction of Ultra High Frequency reader and the passive tag. In general, the range
(UHF) RFID technology has further extended that of passive UHF RFID systems is limited by factors
potential. such as the tag characteristics, the propagation
environment and the RFID reader parameters.
UHF RFID Typically, if reader sensitivity is high then the tag
RFID is a contactless technology that can operate limitations prevail. However, tag range can be
over a range from a few centimetres to several maximised by designing a high-gain antenna that is
metres, using frequencies of 120 to 150 kHz (Low well matched to the chip impedance.
Frequency, or LF), 13.56 MHz (High Frequency, or
HF) and 860 to 960 MHz (Ultra High Frequency, UHF RFID in the IoT
or UHF). Most of the existing applications (such In order to support the use of UHF RFID as an IoT
as identifi cation, access control and payment) use solution, a global alliance was formed in 2014 by
passive devices; that is, the RFID device does not Google, Intel, Impinj, Smartrac and AIM. Marketed
have its own power source, such as a primary cell. as RAIN RFID, it has adopted the EPC Gen 2
This is the primary feature of RFID devices and, in specifi cation, as incorporated into the ISO/IEC
general, devices in the LF and HF frequency ranges 18000-63 standard. If a solution is referred to as
receive their power through inductive coupling RAIN RFID, it will be using UHF RFID technology
(or near-fi eld), while UHF devices use Electro- that complies with this standard and the alliance’s
Magnetic Wave (or far-fi eld) Propagation. goals. •

26 September/October 2018 | Logistics News