What is RFID (Radio Frequency Identification) and how does it work?

Answer 1

Radio-frequency identification (RFID) is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders.

An RFID tag is an object that can be applied to or incorporated into a product, animal, or person for the purpose of identification using radiowaves. Some tags can be read from several meters away and beyond the line of sight of the reader.

Most RFID tags contain at least two parts. One is an integrated circuit for storing and processing information, modulating and demodulating a (RF) signal and can also be used for other specialized functions. The second is an antenna for receiving and transmitting the signal. A technology called chipless RFID allows for discrete identification of tags without an integrated circuit, thereby allowing tags to be printed directly onto assets at lower cost than traditional tags.

For details on how they work, follow the link below.

Answer 2

RFID, stands for Radio Frequency Identification Technology.

In short it's a way of uniquely identifying objects by using radio waves.

Brief History
RFID Technology has been around for a long time, since world war 2 and was used to identify enemy planes (called IFF - Identify Friend Foe System)

It developed and became more commercial over time and today is used a lot with livestock and wildlife tagging (the antenna thing that beeps is RFID) in toll booths, credit cards where you wave instead of swiping it, speed pass for gas stations, keyless entry systems and room access cards etc.

They're two main things in an RFID system, something to ask the question "what's your ID number" (RFID Reader aka Interrogator) and something to respond to the question (RFID Tag aka transponder).

There are also computer systems to understand and translate all this information. In manufacturing, you may want to it realize that a pallet of XYZ has passed through your dock door (if an RFID reader was mounted on your dock door)

RFID Tags, consist of an antenna and an ID# on a chip. Some contain a battery, which it uses to transmit a response back to the Interrogator (called an Active RFID Tag), if it has no battery, it bounces signals back to the interrogator (called a passive RFID tag). If it has a battery but just uses it to power a circuit and not transmit back to the interrogator, then it's called semi passive.

An RFID interrogator sends a signal to a tag which requests it's unique number.

More Technical Answer
Radio Frequency Identification Technology uses various radio frequencies: High Frequency, Low Frequency, Microwave, and UHF etc, to communicate with an transponder (proper name for RFID tag) The interrogator transmits a signal using mainly FSK - Frequency Shift Keying or ASK Amplitude Shift Keying to a transponder which (if a passive tranponder) modulates the signal and reflects it back to the reader, a process called backscattering. The interrogator reads the modulated signal, which now contains the tag's unique ID#. The interrogator passes the info to a computer system/program that does something, like open a door or charge a credit card.

There newer standard for RFID is called Generation 2 RFID. It uses UHF frequency and is supposed to be much better than the older technology...speed, range, bandwidth efficiency, security etc. are better. Walmart, the government, Tesco a UK company, Target lots of companies have adopted and "demanded" use of the RFID by suppliers. Different levels exist, pallet level tagging - tagging a shipping pallet, down to item level tagging which tags an individual item (pricey to have a 50c tag on a $1 worth of shampoo etc.)

If this was part of an manufacturing system, it would pass it on to decision making software called edge servers and middleware.

Active tags have a battery to power the signal transmission back, and thus have much greater range (used in highway drive by toll booths). Other variations exist like smart tags - combination rfid/barcode and chipless tags which basically by design have a unique reflection pattern.

Answer 3

I'm a retired Motorola Tech and I'll take a stab - When operating a xmitter you need a license. Let's say my local police are having interference on their system and they call me. I identify the interference as coming from another station ( xmitter ). A real hard one to repair / resolve for us. Anyway the FCC requires every station to I.D itself with it's call sign that is written on the license every hour. So if I troubleshoot well and can confirm the offending freq. then within an hour I will hear the call sign and can than locate the operator and find out whats gone wrong with HIS equipment. TOO much power out, ovemodulating the carrier, spurious rf. Be live me only about 30% actually ID themselves as they should. Ham radio does it religiously but the are a fanatical group. T.V stations do it - I'm sure you've heard them stop regular programming to say " this is WAGA channel 5 .... "

Answer 4

Read all about it here
http://www.technovelgy.com/ct/Technology-Article.asp?ArtNum=2