An RFID tag on a windshield is a small, electronic identification device typically used for automated vehicle identification and toll collection. These tags function using Radio Frequency Identification technology, allowing scanners to read the vehicle's unique data without requiring a direct line of sight or physical contact.
Key Technical Characteristics
Passive UHF Technology: Most windshield tags are passive (no battery), powered by the electromagnetic energy sent from the RFID reader.
Form Factor: They are usually thin, flexible stickers or "transponders" that contain a microchip and an antenna.
Frequency: In the automotive industry, these typically operate in the 860MHz to 960MHz UHF band (ISO/IEC 18000-6C standard) to allow for high-speed reading as vehicles pass through gantries.
Common Applications
Electronic Toll Collection (ETC): Systems like E-ZPass or various national highway systems use these tags to automatically deduct tolls from a pre-paid account.
Access Control: Used for automated entry into gated communities, parking garages, or corporate campuses.
Fleet Management: Allows logistics companies to track vehicle movement and optimize dispatching.
Placement and Installation
Location: They are generally applied to the interior of the windshield, often behind the rearview mirror, to ensure an unobstructed signal path to overhead readers.
Interference: Certain metallic windshield tints or heated windshields can interfere with the RF signal; specialized tags or specific placement "windows" are often required in these cases.