RFID Tag Antennas

RFID tag antennas are develop for a unique purpose  and their design can actually disclose some information about the tag itself.

You can find whether the tag is Low Frequency, High Frequency, or Ultra-High Frequency, and then have a common idea of the tag’s read range.Generally, if you know what to look for it is pretty easy to detect the frequency at which the tag operates just by examining the tag.That is because the correlation between the tag antenna design and the way the tag talks to the RFID reader/antenna will reveal the frequency.

 Below, the three main frequency types are outlined, including information about each :

Low Frequency (LF)

Frequency: 125 – 135 kHz – generally, 124 kHz, 125 kHz, or 135 kHz

Read Range: Touch to 45.7 cm (18 in) under ideal conditions

Coupling Technique: Inductive coupling – reader’s antenna generates a magnetic field to activate an electric current in the RFID tag antennas

Antenna Design: Typically, circularly coiled tag antenna

High Frequency (HF)

Frequency: 13.553 – 13.567 MHz – generally, 13.56 MHz

Read Range: Touch to around 1.5 m (5 ft.) under ideal conditions

Coupling Technique: Inductive coupling – reader’s antenna generates a magnetic field to activate an electric current in the tag’s antenna

Antenna Design: typically, rectangular or circular-shaped, small tag antenna

Ultra- High Frequency (UHF)

Frequency: 400 – 1000 MHz – generally, 860 – 960 MHz

Read Range: Up to 35 m (115 ft.) under ideal conditions

Coupling Technique: Back-scatter coupling – reader’s antenna generates RF energy to activate the RFID tag, which modulates the information and reflects the remaining energy back to the reader antenna.

Antenna Design: Typically, dipole-shaped RFID tag antennas

Near-Field Capabilities: If it has a small loop-shaped antenna in the middle, it usually has near-field capabilities.