Metal oxide semiconductor device for use in UHF electronic article surveillance systems
AssigneeSensormatic Electronics Corporation
InventorsMing-Ren Lian, Richard Loyd Copeland
Life of this patent
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Abstract
An Electronic Article Surveillance (“EAS”) tag and method and system for deactivating EAS tags without the need to physically contact the tag with a deactivation device. The EAS tag replaces the conventional diode with a non-linear device such as a metal-oxide-semiconductor (“MOS”) capacitor with a given breakdown voltage threshold. Inducing a predetermined voltage across the MOS capacitor results in destruction of the MOS capacitor rendering the EAS tag undetectable in the EAS interrogation system.
Claims20
An electronic article surveillance (“EAS”) tag comprising:
- an antenna circuit;
- and
- a non-linear component electrically coupled to the antenna circuit, the non-linear component exhibiting a non-linear capacitance with respect to voltage below a breakdown voltage threshold and exhibiting irreversible linear capacitance with respect to voltage above the breakdown voltage threshold.
An electronic article surveillance (“EAS”) tag deactivation system comprising:
- an EAS tag, the tag comprising:
- an antenna circuit;
- and
- a non-linear component electrically coupled to the antenna circuit, the non-linear component exhibiting a non-linear capacitance with respect to voltage below a breakdown voltage threshold and exhibiting irreversible linear capacitance with respect to voltage above the breakdown voltage threshold;
- and
- a deactivation device adapted to deactivate the EAS tag without making contact with it.
A method of deactivating an electronic article surveillance (“EAS”) tag, the method comprising:
- providing an EAS tag having an antenna circuit and a non-linear component electrically coupled to the antenna circuit, the non-linear component exhibiting a non-linear capacitance with respect to voltage below a breakdown voltage threshold and exhibiting irreversible linear capacitance with respect to voltage above the breakdown voltage threshold;
- and
- inducing a voltage across the non-linear component, the induced voltage being greater than the breakdown threshold in order to breakdown the non-linear component.
Dependencies are inferred from the claim text.