RFID Technology

RFID Technology

                                                  

What is RFID?

Radio frequency identification, or RFID, It is an automatic identification method, relying on storing and remotely retrieving data using devices called RFID tags or transponders. This RFID rags can be attached to any of the host that can be any object living or non living for the purpose of identification using radio waves.

There are several methods of identification, but the most common is to store a serial number that identifies a person or object, and perhaps other information, on a microchip.

History

The radar system was invented by engineers in the late half of the World War II, which was able to   identify the aircraft but unable to interpret whether the it was the one of their own or was a foe.

British Engineer found a technique called IFF to interpret whether the detected aircraft is a friend or foe which helped  them   to win a lot of battle against the Germans. This technique was the ancestor of RFID which they was commercially practiced and designed in late 1960’s.

How does an RFID system Work?

An RFID system consists of a tag, which is made up of a microchip with an antenna, and an interrogator or reader with an antenna.

The reader sends out electromagnetic waves.

The tag antenna is tuned to receive these waves.

A passive RFID tag draws power from field created by the reader and uses it to power the microchip’s circuits.

The chip then modulates the waves that the tag sends back to the reader and the reader converts the new waves into digital data. 

Working mechanism

The working mechanism is a simple “transmit and receive from reflected” type of mechanism. The transmitter transmits a radio frequency to the RFID tag. Due to this frequency wave, RFID gets enough power to reflect back the data which is stored in it. The reflected wave is then passed back to the receiver. All the functioning of RFID is based on this basic principle except for the different working of the readers and the transmitters.

A basic RFID system consists of three components:

An antenna or coil

Transceiver (with decoder)

A transponder (RF tag) electronically programmed with unique information

RFID System Components

Transponders/Tags

Types of RFID

RFID cards are also known as "proximity" or "proxy" cards and come in three general varieties: passive, semi-passive (also known as semi-active), or active.

Passive

Passive RFID tags have no internal power supply. The minute electrical current induced in the antenna by the incoming radio frequency signal provides just enough power for the CMOS integrated circuit (IC) in the tag to power up and transmit a response. Most passive tags signal by backscattering the carrier signal from the reader. This means that the aerial (antenna) has to be designed to both collect power from the incoming signal and also to transmit the outbound backscatter signal. The response of a passive RFID tag is not just an ID number (GUID); the tag chip can contain nonvolatile EEPROM for storing data.

Active

Unlike passive RFID tags, active RFID tags have their own internal power source which is used to power any ICs that generate the outgoing signal. Active tags are typically much more reliable (e.g. fewer errors) than passive tags due to the ability for active tags to conduct a "session" with a reader.

Data Storage in RFID

The data to be stored is generally an ID that can be stored encoded in the standards EPC scheme i.e. Electronic Product Code Scheme. The Electronic Product scheme supports the following encoding schemes:

SGTIN-64

RAW EPC-64

SGTIN-96

SSCC-96

SGLN-96 

DOD/UID-96 

Areas of Application for RFID

Potential applications for RFID may be identified in virtually every sector of industry, commerce and services where data is to be collected. The attributes of RFID are complimentary to other data capture technologies and thus able to satisfy particular application requirements that cannot be adequately accommodate by alternative technologies. Principal areas of application for RFID that can be currently identified include:

Transportation and logistics

Manufacturing and Processing

Security

Human Implants

1) Hand with the planned location of the RFID chip

2) Just after the operation to insert the RFID tag was completed

Some FAQs

Are there any health risks associated with RFID and radio waves?

Ans:-RFID uses the low-end of the electromagnetic spectrum. The waves coming from readers are no more dangerous than the waves coming to your car radio

Why is RFID better than using bar codes?

Ans:- RFID is not necessarily "better" than bar codes.

Both are different

Barcode- Line of Sight

Rfid – Range of Sight

Barcodes can be ripped off

Will RFID replace bar codes?

Ans:-Probably not. Bar codes are inexpensive and effective for certain tasks. It is likely that RFID and bar codes will coexist for many years.

How much information can the tag store?

Ans:-It depends on the vendor and the application,

A tag would carry no more than 2KB of data—enough to store some basic information about the item it is on.

Companies are now looking at using a simple "license plate" tag that contains only a 96-bit serial number. The simple tags are cheaper to manufacture and are more useful for applications where the tag will be disposed of with the product packaging

What is the read range for a typical RFID tag?

Ans:-The read range of passive tags (tags without batteries) depends on many factors: the frequency of operation, the power of the reader, interference from metal objects or other RF devices. In general,

Low-frequency tags are read from a foot or less.

High frequency tags are read from about three feet

UHF tags are read from 10 to 20 feet.

Where longer ranges are needed, such as for tracking railway cars, active tags use batteries to boost read ranges to 300 feet or more.