RFID

Radio Frequency Identification / Automatic Identification

RFID is a microchip the size of a grain of sand containing a number. The microchip is attached to an antenna and creates a miniature radio station for broadcasting that number over RF (Radio Frequency). The microchip may also be able to do other things (contain data, tell time, encrypt data, or provide temperature readings). Generally, these additional features are no longer RFID but a custom solution.

RFID Capabilities

Passive RFID chips are low cost ($0.20 cents to one dollar) and are being used on over ten million logistics shipments per month. These passive chips come in sizes from 1.5"x0.5" to 4"x4". They have a transmission range of 4 feet to 60 feet, depending on the chip size and RFID reader antenna power.

Active RFID chips are expensive ($15.00 USD to $500.00) and are used in selective applications where real-time location is needed on an item. Active chips contain a battery that typically lasts for five years and has an accuracy of 1 to 5 feet.

The ID (Identification)

As of January 2009, the most common ID (Identification) is a 96-bit number stored in the tag. This number is programmed into the tag and the tag waits for a request to provide it's ID. When it receives the request, it transmits it's ID and the system knows this ID has arrived in your facility.

The RF (Radio Frequency)

There are four major RF choices. UHF is the most popular due to its low cost (20 cents, typical) and use in the DoD, Wal-Mart, and Target logistics systems. UHF operates at 900Mhz and provides ranges up to 60 feet. HF and LF systems have existed far longer than UHF technology but they are losing ground due to very short read range (< 3 feet) and very high cost due to low production volumes.

The fourth RF area is active RFID. Active RFID tags have not standardized and each manufacturer creates it's own solution and technology.

Examples of RFID deployments

- DoD RFID Logistics tagging -- Tagging millions of shipments to identify the shipment contents, automatically.