About RFID
Understanding how RFID works in traditional HF applications and using new generation UHF technology
'Legend' has it the RFID was 'invented' in 1945 as an espionage tool for the Soviet (Russian) government. By the '60's, RFID had evolved to the point where it could be successfully applied in commercial use in areas such as security and asset tracking. By the '80's, standard HF RFID had become commonplace in both daily public life and for a host of commercial applications. Recent years have seen the development of a Second Generation of RFID using the UHF (ultra high frequency) radio band. With its greater range and numerous other benefits, UHF has opened up RFID to many more sophisticated functions, with many potential new uses still being experimented with.
We're all familiar with the tags (data carriers) and readers involved in RFID installations. The tags can be passive or active. Active tags contain a battery and can generate an outgoing signal with longer range and have the ability to store information (such as product color).
RF simply means Radio Frequency, a radio signal that provides a contactless link to an information storage unit (reader). This allows for applications like product tracking. Generally speaking, the tags are relatively cheap to produce, making them practical for use in quantity for purposes such as inventory control. Today's RFID tags have read-write capability, are re-usable, highly durable, have data security features and multiple read capability (50 to 100 tags can be read simultaneously).
The other components of an RFID system are a transponder, an antenna, an RFID reader/writer and a host system (computer with specialized software).
Like the regular radio people listen to, RFID operates on the spectrum of radio frequency bands controlled by government radio regulation authorities (the FCC in the U.S., the CRTC in Canada).
For RFID use, there is an LF band at 135 kHz and the HF band at 13.56 MHz. The new UHF technology operates on 868MHz in Europe and 915MHz in North America. As yet, there is no universal UHF frequency.
In passive transponder systems, the transponder (tag) is energized by the RF field and transmits its ID to the reader, allowing for tracking and other basic uses. In active transponder systems (tags with batteries), the transponder is turned on by a specific RF field from the reader, allowing it to communicate with the reader through a set of pre-determined protocols. Thus it acts as a 'beacon', continuously transmitting its presence.
What is RFID?
WHERE UHF TAKES RFID
UHF systems have a far greater range – they can be read from 20 feet away, whereas an HF transponder is limited to about 3 feet.
UHF tags are small and can be more easily and more discretely embedded into items to be tracked.
UHF systems are much faster and have higher capability (as much as 800 reads per second).
UHF tags can hold vastly more information than HF tags and even perform such functions as the automatic sending of e-mail.
UHF signals are impervious to things like metal and water (unlike HF tags).
These and many other features give UHF systems the power and versatility to be used in applications where traditional HF RFID was impractical. Though many highly efficient UHF applications are already in place, the true potential of UHF RFID is largely untapped. Beacontree Technologies has positioned itself to be in the forefront of this emerging technology.