RFID
White paper
To learn more about RFID and its applications please read RFID White paper.  |
RFID Introduction
RFID (Radio Frequency IDentification) is a system using a tag and reader where the contents of the tag can be read without coming into physical contact with the reader. It is a system superior to barcodes because line-of-sight is not required, the tag has more memory, and the content can change for read/write tags.
RFID is not really a new technology. It has been in use since World War II to identify airplanes as friend or foe.
Purpose of RFID
RFID allows data to be transmitted by a product containing an RFID tag microchip, which is read by an RFID reader. The data transmitted can provide identification or location information about the product, and other related information which may be stored on the RFID tag or on centrally connected database.
RFID Tags
RFID tags are very small microchips with memory and an antenna coil. RFID tags listen for a radio signal sent by a RFID reader. When a RFID tag receives a signal, it responds by transmitting its unique ID code and other data back to the reader. There are two types of RFID tags:
| Passive RFID tags can be as small as 0.3mm and don't require batteries. These tags are powered by the radio signal of a RFID reader, which "wakes them up" to request a reply. Passive RFID tags can be read from a distance of about 20 feet. Semi-passive RFID tags contain a small battery that boosts the range. Passive tags are generally read-only. |
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| Active RFID tags also called transponders because they contain a transmitter that is always "on", are powered by a battery, about the size of a coin, and are designed for communications up to 100 feet from the RFID reader. They are larger in size but can hold more data about the product and are commonly used for high-value asset tracking. Active RFID tags may be rewriteable |
RFID System Frequency Ranges
There are 4 major frequency ranges of RFID systems. Low-frequency systems are distinguished by short reading ranges, slow read speeds, and lower cost. Higher-frequency RFID systems are used where longer read ranges and fast reading speeds are required, such as for vehicle tracking and electronic toll collection. Microwave requires the use of active RFID tags.
| Frequency |
Range |
Applications |
Low Frequency
125 - 148 KHz |
1.5 feet |
Pet and ranch animal identification; car key locks |
High Frequency
13.56 MHz |
3 feet |
Library book identification, DVD rental clothing identification; smart cards |
Ultra High Frequency
915 MHz |
25 feet |
Supply chain tracking: Box, pallet, container, trailer tracking |
Microwave
2.45 GHz |
100 feet |
Highway toll collection; vehicle fleet identification |
RFID White paper
To learn more about RFID and its applications please read RFID White paper.
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