AM vs RF: Which EAS format should you choose?

AM operates at 58 kHz using a swept-frequency signal that energizes the tag at its resonant frequency. The tag — a strip of amorphous metal alloy — vibrates mechanically and emits a distinctive signature that the receiver detects even in high-noise environments. This physical resonance mechanism makes AM extremely resistant to interference from other electronic devices.

AM excels in grocery, pharmacy, and cosmetics environments because the 58 kHz signal is not significantly absorbed by water or metal. A bottle of shampoo, a metal can, or a foil-lidded container will not block AM detection the way it blocks RF. Gate widths of 1.2-1.8 meters are standard.

RF operates at 8.2 MHz using a continuous-wave signal. RF labels contain a coil and capacitor forming an LC circuit tuned to 8.2 MHz; when disrupted at the POS by a strong magnetic field, it is permanently deactivated. RF labels can be made extremely thin (0.1mm) and are nearly invisible when concealed inside clothing labels or packaging.

RF major advantage is gate width: a single pair of RF pedestals can cover up to 2.5-3.0 meters — the widest of any EAS technology. This makes RF well-suited to large exits or wide aisles in department stores and fashion retailers.

Choose AM if: your products contain metal, liquid, or foil packaging; you sell food, beverages, pharmaceuticals, or cosmetics; you need very low false-alarm rates in high-traffic areas; or you need factory-level source tagging.

Choose RF if: you sell apparel, soft goods, or accessories; you need to cover wide exits (2.0m+); you want the thinnest possible labels for aesthetic concealment; or your existing store infrastructure already supports RF. When in doubt, SDNI recommends an on-site trial with both systems before committing.