What's the difference between passive and active tags?

Active RFID tags have a transmitter and their own power source (typically a battery). The power source is used to run the microchip's circuitry and to broadcast a signal to a reader (the way a cell phone transmits signals to a base station). Passive tags have no battery. Instead, they draw power from the reader, which sends out electromagnetic waves that induce a current in the tag's antenna. Semi-passive tags use a battery to run the chip's circuitry, but communicate by drawing power from the reader. Active and semi-passive tags are useful for tracking high-value goods that need to be scanned over long ranges, such as railway cars on a track, but they cost more than passive tags, which means they can't be used on low-cost items. (There are companies developing technology that could make active tags far less expensive than they are today.) End-users are focusing on passive UHF tags, which cost less than 40 cents today in volumes of 1 million tags or more. Their read range isn't as far��typically less than 20 feet vs. 100 feet or more for active tags��but they are far less expensive than active tags and can be disposed of with the product packaging.

» Print |

Recommendatory

› How can a passive RFID tag accommodate all the data desired?
› What is the read range for a typical RFID tag?
› How is the information stored on an RFID tag?
› What is tag collision?
› How well will RFID work in a military manufacturing environment where metal tool
› What is the relationship between frequency and tag/antenna distance?
› What's the difference between read-only and read-write RFID tags?
› What are the smallest tags/labels available today?
› What is energy harvesting?
› Can you use smart labels on metal shipping pallets or skids?