There are not complicated that the basic working principle of RFID technology:

Receiving the reader signal when tag coming magnetic field. With induction current and gain energy after sending product information of storage in the chip( Passive tag)， or send one of some frequency signal by active ,(Active Tag); When Reader reading information and decode, it will send information to CIS deal with data.

Rapid rise develop of UHF FRID technology, not only consequence of technology development, but also manifest of application. From 90’s beginning, the various of application around RFID have sprung up. Today, we simple introduce RFID technology and one of the most important product——card Reader.

In the radio frequency field,  According to the frequency that we divide into six section of electric induction wave. But the mainly work in 3 frequency bind. Low frequency(30~300KHz)、High Frequency(13.56MHz) and Ultra High Frequency(300MHz~3GHz). Commonly working frequency have LF125Khz and 134.2KHz、HF13.56MHz 、UHF433MHz 860MHz~930MHz, 2.45GHz etc. Low frequency mainly application use for short distance and low cost. Ex: Access control, campus card, gas meter, water meter, etc. HF systems are used in applications that need to transfer large amounts of data. UHF is use in applications where long distance high read and high writ. Ex, the train monitoring, highway tolls and other systems, but antenna wave direction is narrow and the price is higher.  Another, UHF RFID product are often use on chain Management, Wal-mart, Metro, Gillette, P&G etc, company use it as an innovative means of improving the management system. The carrier frequency specified by standard the EPC (introduce in the below) is 13. and 860~930MHz, but 13.56MHz using the standard protocol type is ISO/IEC15693, has been income to ISO/IEC18000-3.

Standard of RFID

As a commercialize technology, RFID has its own standard, too. ISO(International standard organization) make a serious standard for it.

Another, numerous develop manufacturer also form alliance, make own technology standard, this is standard of EPC. It’s also a standard of the widest application at present. RFID system was divides into 4 level by EPC, including physics layer, middle layer, internet layer and application layer. Physics layer is all systems construct of physics environment. , including tag antenna, reader, sensor, instrument and meter hardware equipment etc. middle layer is information collection middleware and application interface, in charge of card reader collection information from tag and pre-deal simple information, then it’s send information  trans to interwork layer or application layer data interface. Interwork layer is link between inter system and data system, interaction transmission on kinds of information.  Application layer is back-end of software and company application system. On a clear system level, EPC standard also collection data format., and regulate output and transmissions program. So, there will be strict and order of RFID system.

The base of analyte information carrier is electric label. It’s type of two. One is active, the other is passive, it’s no power, provide electric by outside. So, what provide electric to it? It’s card reader of RFID system. It’s a RF transceiver, it will activating electric label by beam signal when it working. If it knock on passive tag, and give it energy.

Of course, electrical transmission has limited for kinds of outside condition. Like in the united State, it’s not allow passive transmission when the energy beyond 1W.  And strict on performance requirement for card reader. Because it must be distinguish reflect the weak signal label from receiving a serious reflect signal. Many card reader have a question that wrong read date, it’s also become a barrier to the development of RFID technology.