Types of RFID Tags:
RFID tags can be either active, semi-passive or passive:
- Passive RFID tags have no internal power supply and rely on the reader to excite an electromagetic response.
- Semi-passive RFID tags are very similar to passive tags except for the addition of a small battery which allows for faster response and an extended reading radius.
- Active RFID tags, or beacons, have their own internal power source which allows them to generate an outgoing signal to transmit information directly to a reader.
The particular information retrieved by an RFID reader is ultimately processed according to the needs of a particular application. The information data may provide identification or location information, or specifics about the product tagged, such as price, color, date of manufacture, etc.
RFID System Frequency Ranges:
RFID systems operate within 4 major frequency ranges. Genearally speaking, 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 automated toll collection. Microwave requires the use of active RFID tags.
| Frequency |
Range |
Application Examples |
Low-frequency
125 - 148 KHz |
3 feet |
Pet and ranch animal identification;
car keylocks |
High-frequency
13.56 MHz |
3 feet |
library book identification;
clothing identification; smart cards |
Ultra-high freq
915 MHz |
25 feet |
Supply chain tracking:
Box, pallet, container, trailer tracking |
Microwave:
2.45GHz |
100 feet |
Highway toll collection;
vehicle fleet identification |
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