RFID FOR DUMMIES

Radio Frequency identification - RFid, the technology of tomorrow, is here today. In fact, billions of tags (circa 5/2010) are in use worldwide, yielding benefits from livestock tracking to vehicle immobilization. This is such a huge number that it makes one question calling RFID an emerging technology.

At its most basic level, it identifies unique objects, processes, transactions or events. RFID does this by using a burst of radio waves to move information. It is possible to explain RFID using only two basic building blocks - Tag and Reader. Of course, they may be configured in sophisticated ways to create large networks capable of staggering data flows.

A unique serial number is stored on a microchip that is the size of the period at the end of this sentence. A tiny antenna is also attached to the microchip. Together, the chip and antenna are called a tag. Typical tags range in size from a stamp to a credit card. The built-in antenna allows the tag to receive information from a device called a reader. Reader(s) and tags transmit information over the air using radio waves. The reader then converts the radio waves from the tag into digital information that's forwarded to a down stream computer.

Let's get started by learning more about TAGS...

...RFID systems include electronic devices called tags (aka transponders) which minimally consist of a microchip, memory and an antenna. Microchips are the brains for the Tags. Information which is sent or received from the radio waves is then stored or recalled from the tag's memory. The antenna has only one task to do; however, that task has a specific direction. It handles communication from either the Tag to the Reader or from the Reader to the Tag. Think of the antenna as a language translator converting digital data into analog (aka radio wave energy) or vice-versa.

Q. Do you know why radio wave energy is so advantageous for transmitting information?

A. Several big advantages of radio waves are their ability to penetrate surfaces at amazing speed. A radio wave travels around the earth 7 times in one second making it a very cost effective and capable of moving information.

In every installation the radio waves travel in an infinite number of differetn path and each will vary in strength. The antenna's ability to deal with this variance is dependent on the engineering parameters of its design plus environmental factors of sending signals through walls vs. open space. Also any nearby interfering radio signal(s) may jam or degrade the desired signal. If the signal strength is either too weak or unreadable due to interference, the receiver can no longer decode infromation from the radio waves. Because of these factors the radio link is the critical design factor for a reliable system.

A Tag physically attaches to something thereby allowing its location, condition or status to be tracked via information sent using radio waves. Decoding of a Tag occurs when it enters the READER's antenna read zone. By definition, we define a read zone as the sweet spot of the antenna where radio waves may be sent and received in such a way that reliable communications take place between the Tag and the Reader. To further harden the communications on the radio link clever algorithms are able to resend or even repair damaged information.

RFID tags come in a wide variety of sizes, shapes and forms but have common attributes, such as: low-energy transmit and receive antennas, data storage and operating circuitry. Tags come with and without batteries, they can be read only or read/write. Typically, tags without batteries (passive) are smaller and lighter than those that are active (with batteries), and less expensive.

When multiple tags are present in the antenna's sweet spot the Reader uses special algorithms to handle collission and arbitration. Once data is sent by Tags and captured by the Reader, it is transferred through standard interfaces to a host computer, printer, database or programmable logic controller for storage or action.

Reader electronics maybe stationary, mobile or handheld. They are linked to other software systems that control the flow of data. In some cases the readers must power, engage, download and retransmit data to the tag they encounter. There are many suppliers of these systems, ranging from large semiconductor companies like TI, Motorola, and Philips, down to niche entrepreneurial businesses.

Today, we are migrating from multiple proprietary systems to standards from industry organizations like ISO or EPCglobal. Prices of tags range from 5 cents to $250.00 depending upon features, functionality and volume. We expect the price of passive tags to fall as RFID adoption increases.

It is important to realize that RFID is not just about the hardware, tags and receivers that comprise the physical infrastructure. It is also about the design and velocity of data that an RFID solution creates and streams. Clever integration of this data with your existing business processes can offer a huge payoff. After all, even the best technology is only as good as the process foundation it works from.