Its label:
RFID backscattering.
Electronic tags (2 pieces) RFID tags are divided into passive, semi-passive (also known as semi-active) and active.
passive voice
Passive tags have no internal power supply. Its internal integrated circuit is driven by the received electromagnetic wave, which is emitted by the RFID reader. When the tag receives a strong enough signal, it can send data to the reader. These data include not only the ID number (globally unique ID), but also the data pre-existing in the tag EEPROM.
The advantages of passive tags are low price, small size and no power supply. At present, RFID tags on the market are mainly passive.
Semi-active
Generally speaking, the antenna of a passive tag has two tasks: one is to receive the electromagnetic wave emitted by the reader and drive the tag IC; Second, when the tag sends back the signal, it needs to switch through the impedance of the antenna, resulting in the change of 0 and 1. The problem is that in order to have the best return efficiency, the antenna impedance must be designed as "open circuit and short circuit", which will make the signal completely reflected and unable to be received by the tag IC. Semi-active tags are designed to solve this problem. Semi-active is similar to passive, except that its battery is very small, and the power supply can just drive the tag IC to make it work. The advantage of this is that the antenna can be used as a return signal completely, regardless of the task of receiving electromagnetic waves. Compared with passive type, semi-active type has faster reaction speed and higher efficiency.
active
Different from passive and semi-passive, active tags have their own internal power supply to supply the power needed by internal IC to generate external signals. Generally speaking, active tags have long reading distance and large storage capacity, which can be used to store some additional information sent by readers.
Radio frequency identification technology includes a set of information technology infrastructure, including:
Radio frequency identification tags, also known as radio frequency tags and electronic tags, are mainly composed of large-scale integrated circuit chips with identification codes and transceiver antennas. At present, it is mainly passive, and the electric energy in use is taken from the radio wave energy received by the antenna. Radio frequency identification reading and writing equipment, and networking with corresponding information service systems such as inventory and sales systems.
Comparing radio frequency identification technology with bar code technology, radio frequency category has many advantages, such as:
Can accommodate more capacity. Long communication distance. It's hard to copy. Have a high tolerance for environmental changes. Multiple tags can be read at the same time.
Relatively speaking, its disadvantage is that the construction cost is high. However, through the extensive use of this technology, the production cost can be greatly reduced.