Insights · EAS Antennas
EAS antennas are the silent guardians at every retail entrance — but how do they actually detect a stolen item leaving the store? This guide explains the technology behind electronic article surveillance antennas, the real difference between AM and RF systems, and how to pick the right antenna setup for your shop.
EAS antennas — also called EAS pedestals, gates, or detection towers — are the visible pillars you see at the entrance and exits of retail stores. They form the detection half of an Electronic Article Surveillance (EAS) system, working alongside security tags and labels attached to merchandise.
When an active tag or label passes between the antennas without being deactivated at the till, the antennas detect it and trigger an audible and visual alarm. The system is designed to be reliable, fast, and unobtrusive — customers walk between the antennas thousands of times a day without ever noticing them.
The technology depends on which EAS system your store uses:
AM antennas emit a pulsed magnetic field at approximately 58 kHz. When an AM security tag or label enters the field, a thin strip of magnetostrictive metal inside the tag resonates and sends back a signal. The antennas pick up that signal, recognise it as an active tag, and trigger the alarm.
AM is the most widely used technology in South African retail because it offers excellent detection range (typically 1.2–2.4 metres between pedestals), strong performance around metal shelving, and very low false-alarm rates.
RF antennas broadcast a sweeping radio signal between 7.4 and 8.2 MHz. Soft labels and hard tags contain a small RF circuit that, when energised by the antennas, produces a harmonic response. The antennas detect this response and trigger the alarm.
RF is generally more affordable than AM, making it popular in clothing boutiques, pharmacies, and smaller specialty stores. However, RF can be more prone to false alarms in stores with high electronic noise or metal fixtures.
A complete EAS detection system has three core pieces:
Modern SLP Technologies pedestals combine the transmitter and receiver into a single sleek tower, simplifying installation and keeping the store entrance clean.
The right antenna setup depends on entrance width, store environment, and stock profile:
For most boutiques and smaller stores with a single entrance, two pedestal antennas spaced 1.2–1.8 m apart provide complete coverage. The SLP Technologies team measures your entrance and recommends the exact pedestal spacing for your floor plan.
Supermarkets and big-box retailers often need ground-loop antennas or extra pedestal pairs to cover entrances wider than 4 metres. Ground loops are concealed under the floor for a clean look while delivering the same detection range.
For busy stores with high theft risk, SLP recommends advertising pedestals — antennas with integrated digital signage. The bright display doubles as in-store marketing while the pedestal still performs full AM detection.
Opticians, jewellers, and high-end boutiques often prefer Claro transparent antennas — clear acrylic pedestals that protect stock without visually dominating the entrance.
EAS antennas look simple, but their detection performance depends heavily on correct installation. Pedestal spacing, height, distance from metal, and orientation relative to electrical interference all affect how reliably the system detects tags.
SLP Technologies provides a full site survey and certified installation with every EAS system. The survey identifies the right pedestal model, the correct spacing for your entrance width, and the ideal placement to maximise detection while eliminating false alarms.
SLP Technologies will survey your store and recommend the ideal antenna configuration for your entrance, stock profile, and budget.
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