What is RFID?

Radio Frequency Identification is a means of capturing data about an object without using a human to read the data.

Yes, and bar codes and RFID both belong to a group of technologies called Automatic Identification and Data Capture. Along with Smart cards, and Magnetic Stripe technology and a host of others, this is a method of automating our need for data.

We have all become very aware of bar codes as they have permeated our existence in the last 25 years. In fact, it is tough to buy something in a store that does not use bar codes these days. But bar codes have four disadvantages that it would be nice to eliminate:

1. You have to be able to see them
2. The bar code cannot be written on or defaced
3. You cannot change the data once they are printed
4. They take up space on the object they are printed on

But what is RFID and what is all this hoopla about? For those of you who are coming to Radio Frequency Identification (RFID) for the first time, a brief introduction is called for. This technology has been around for many years, but it is only in the past few years that we have seen a surge in its acceptance and a massive growth in its use. AIM has published a history of RFID and you can get more information from the web site at Shrouds of Time - A History of RFID

From its first uses back in the 1940s, RFID suffered a very slow start and it is only since 1997 that we have seen the massive growth in the industry as technology caught up with the desires and the possibility of low cost tags was realized. Now we have the capability to make tags at a reasonable cost and the opportunities are beginning to really show themselves. As I look at my database, there are 338 companies that have identified themselves as being involved in RFID around the world. When you consider than maybe only five years ago, you could count the suppliers on your fingers, this is a massive increase.

The technology uses a very simple idea that has many complications involved in its execution. A reader/interrogator/scanner transmits an RF wave to a tag. The tag "hears" the RF wave, and responds with some data. Tags come in many flavors: passive, battery assisted, active, backscatter, different frequencies, tag talks first, reader talks first, various anti-collision techniques or not, printed antennas, wire wound antennas, hard case, label, etc. So many variations that it can be very confusing, but there is good news. Your application will define many of these for you, and working with your supplier/integrator you will rapidly choose the solution that is best for you.

So lets learn about the technology.

The Technology