Transponder – Definition and How It Works
A transponder is a small radio device that sends an identifier when a reader queries it – the foundation of RFID access systems.
Structure and types
A transponder is a small radio device that sends an identifier when queried by a reader. Passive transponders draw energy from the reader field, active transponders have their own battery and greater range.
Form factors range from cards and key fobs to stickers, wristbands or chips embedded in tools.
Use in access systems
- Employee and visitor badges
- Opening of doors and lockers
- Tagging of tools and equipment
- Time tracking and zone access
Frequently Asked Questions
Difference between card and transponder?
Cards are one form factor of transponders. Transponder is the umbrella term.
Can transponders be programmed?
Yes, if they are writable. Many access applications use the fixed UID.
How long does a passive transponder last?
Practically unlimited, as there is no battery. Active transponders last several years depending on type.