The following is a system introduction to three types of electronic article surveillance (EAS) technologies: radio frequency (RF 8.2MHz), acoustic magnetic (AM 58kHz), and electromagnetic (EM)
RF system (RF 8.2MHz)
Core principle
The transmitter forms an 8.2MHz sweep frequency electric field at the outlet (sweep frequency range of about 1MHz), and the LC resonant circuit (capacitor+inductor) built into the tag resonates at the matching frequency, perturbing the electric field and triggering the receiver alarm. The tag needs to be unlocked using a dedicated unlocking device to release the magnetic lock.
Technical characteristics
Label type: Hard label (such as Mini Square type, size 48mm × 42mm), with weak resistance to metal shielding.
Detection distance: 1.0-1.5 meters (significantly affected by environmental interference).
Cost advantage: The unit price is as low as $0.005-0.20/piece, suitable for low-cost deployment.
Acoustic magnetic system (AM 58kHz)
Core principle
Based on the magnetostriction effect: the transmitter generates a 58kHz alternating magnetic field, activates the thin strip of PoMo alloy inside the label, and generates a resonance signal; The receiver captures four consecutive resonance waves (with an interval of 1/50 second) to trigger an alarm.
Disruptive advantage
Performance parameters of indicators
Detection rate>95%, close to zero false alarms
Anti interference and anti metal shielding, supporting 4-meter wide channels
Intelligent processing Cortex-M3 processor+FFT algorithm, frequency detection accuracy ± 600Hz
Electromagnetic System (EM)
Basic characteristics
The working frequency band is 1-2MHz, and non demagnetized tags are identified through electromagnetic induction. The technology maturity is high, but the detection sensitivity and anti-interference ability are weaker than those of acoustic magnetic systems.
Application limitations
Mainly suitable for book and document management, gradually replaced by RF/AM in the retail field.
Comparison and Evolution of Three Types of Technologies
System type, operating frequency, label characteristics, applicable scenarios
RF 8.2MHz low-cost LC resonant tag for clothing and daily necessities retail
AM 58kHz PoMo alloy thin strip, high robustness for high-end shopping malls and supermarkets
EM 1-2MHz magnetic stripe label library and archive management
Fusion trend:
Dual band tag: Supports dual mode triggering of RF 8.2MHz and AM 58kHz, suitable for mixed detection environments.
Intelligent integration: AI optimized signal processing, reducing missed detection rate by 60%; Cloud platform enables remote monitoring of devices.
The current EAS technology is evolving towards multi frequency compatibility and intelligent analysis. RF and AM systems dominate due to their balanced performance and cost, while EM systems focus on segmented scenarios.
