RFID, which means Radio Frequency Identification, is a common technology used for tracking, counting, and many other tasks which require an operator or a system to know where things are.
RFID tags are mainly made up of an RFID integrated circuit (IC), a coil antenna, and a substrate. RFID tags can be divided into three basic categories: Passive, Active, and Semi-Passive (also called Battery-Assisted Passive , BAP).
- Passive RFID tags have no internal power source. The electromagnetic energy from the RFID reader is the only power source.
- Active tags are different from Passive tags. Active tags have internal batteries.
- Semi-Passive is similar to the Passive tags but they have internal batteries.
| Types | Advantages | Disadvantages |
|---|---|---|
| Passive tags | 1. Without any battery (some tags may have long life time, more than 20 years) 2. Cheaper and smaller size |
1. Shorter read ranges (up to a few feet) 2. Requires external power from the reader |
| Active tags | 1. Longer read ranges (100 feet or more) 2. Reduced power from the interrogators 3. Can have more memory to store data |
1. Shorter battery time 2. Quite expensive and bulky 3. Increase the maintenance cost of battery replacement 4. Require the presence of interrogator to work |
| Semi-Passive tags | 1. Long read ranges (around 100 feet) 2. Reduced power from the interrogators 3. Can have more memory to store data |
1. Short battery life 2. Bulky and weight 3. Require the presence of interrogator to work |
There are 3 main frequency ranges of RFID tags: Ultra-High Frequency (UHF), High Frequency (HF), and Low Frequency (LF). Microwave RFID is also available in the market.
| Range | LF | HF | UHF |
|---|---|---|---|
| Typical Frequency Ranges | 125kHz | 13.56MHz | 433MHz & 860-960MHz |
| Read Range | Short (<10cm) | Medium (< 1m) | Long (up tp 10m) |
| Data Rate | Low | Low to moderate | High |
| Standard | ISO 11784 & ISO 11785 | ISO 14443 & ISO 15693 & NFC | ISO 18000 |
| Usage | Access Control, Animal Tagging, Inventory Control, Car Immobilizer | Smart Cards, Item or Case level Tagging, Proximity Cards, Vicinity Cards | Asset Tracking, Locationing, Container Tracking, Pallet or Case Level Tagging, DOD & Walmart Mandates |