The application scope of RFID tag _ printing devices
RFID ( Rfid tags) Technology is a kind of comprehensive automatic identification technology ( Auto- ID) And the new technology of radio frequency communication technology. It is in the network, economy, culture, life, moral and ethical, legal, military, and so on many aspects to bring radical change, after Internet and wireless and mobile communications become a decisive power to social change. And may eventually and Internet ( IPV6) , mobile communication network, wireless sensor networks, such as biometric technology, GPS technology integration.
the RFID tag ( According to the communication mode) Divided into passive, passive ( Also known as semi-active) , take the initiative to three categories.
passive tag has no internal power supply. The internal integrated circuit to drive through the received electromagnetic waves, the electromagnetic wave is made by the RFID reader. When the label to receive enough strength of the signal, can send data to the reader. These data not only include the ID number ( The only global label ID) , can also include exists in advance label data in a block in the EEPROM.
due to the passive tags with low price, small size, the advantages of without power supply. RFID tag mainly passive in the market.
in general, the passive tag antenna has two tasks, the first: receive the electromagnetic wave emitted from the reader, so as to drive the tag IC; The second: the tag echo signal, the need to make a switch on the impedance of the antenna, to generate the change of 0 s and 1 s. Rebound, the problem is, want to have the best efficiency, antenna impedance must be designed in open circuit and short circuit, can make signal reflected completely, and so cannot be tag IC receiver, semi active tags in order to solve this problem. Instn is similar to the passive, but it is much more a small battery, power can drive the tag IC, the IC is in a state of work. Such benefits, the antenna can be receiving the task of electromagnetic wave, sufficient for the use of echo signal. Rather than passive, semi active has faster response speed, better efficiency.
unlike passive and half passive and active tags itself has internal power supply, internal IC to supply the power needed to produce the external signal. In general, active tags have longer reading distance and large memory capacity can be used to store some additional messages transmitted by the reader.