Active RFID Tags
Active tags may be operated in two main modes:
1. Active Transponders
- Activated (“awakened”) when they receive a signal from a reader.
- Used in toll payment collection, checkpoint control and other choke-point systems.
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Example: When a car with an active transponder approaches a tollbooth, the reader sends a signal that activates the transponder on the car windshield; the transponder then transmits its unique ID to the reader.
- Conserves battery life by transmitting only when within range of a reader.
2. Active Beacons
- Used in real-time locating systems (RTLS) that cannot accommodate choke points.
- Emit a signal with their unique identifier at pre-set intervals (every second, minute, hour, or multiple times per day, depending on application urgency).
Key Characteristics of Active Tags
- Transmit their own signal rather than reflecting a reader’s signal.
- Typical read ranges of up to 100 m (300+ ft), depending on antenna type, environment and regulations.
- Cost ranges from about $10 to several hundred dollars, depending on:
- Capability
- Amount of memory
- Battery life
- Integrated sensor functionality