A complete RFID system is composed of tags, readers and data transmission processing systems. Generally divided into active RFID, semi-active and passive RFID. The inside of the RFID tag is a chip with an antenna. The chip stores information that can identify the target, and its main function is to identify the goods.
The difference between active, semi-active and passive RFID tags:
1. Different concepts
Electronic tags can be divided into active electronic tags (Activetag), passive electronic tags (Passivetag) and semi-passive electronic tags (Semi-passivetag).
Active rfid, also known as active rfid, is a type of electronic tag divided by the different power supply modes of the electronic tag, and it usually supports remote identification.
Semi-active rfid integrates the advantages of active RFID electronic tags and passive RFID electronic tags, as a special marker. In most cases, it is often in a dormant state and does not work, and does not send an RFID signal to the outside world. Only when it enters the activation signal range of the low-frequency activator, the tag starts to work.
Passive rfid, that is, the passive radio frequency tag adopts frequency hopping working mode and has anti-interference ability. Users can customize the read and write standard data, which is more efficient in special application systems, and the reading distance can reach more than 10 meters.
Two, the working principle is different
An active electronic tag means that the energy for the tag is provided by the battery. The battery, chip and antenna together form an active electronic tag. It is different from the passive radio frequency activation method. It always sends information out of the set frequency band before the battery is replaced.
Semi-active rfid, common active electronic tags work in the 433M frequency band or 2.4G frequency band. It works normally after being activated. The activation distance of the low-frequency activator is limited. It can only be accurately activated in a small distance and a small range. In this way, the low-frequency activator is used as the base point for positioning, and different base points are installed in different positions, and then used for a long distance in a large area. The reader recognizes and reads the signal, and then uploads the signal to the management center in different uploading methods. In this way, the entire process of signal collection, transmission, processing, and application is completed.
The performance of passive rfid tags is greatly affected by the tag size, modulation form, circuit Q value, device power consumption and modulation depth. Passive radio frequency tags have 1024bits memory capacity and ultra-wide working frequency band, which not only conforms to relevant industry regulations, but also enables flexible development and application, and can read and write multiple tags at the same time. Passive radio frequency tag design, without battery, memory can be repeatedly erased and written more than 100,000 times.
3. With or without built-in battery
Active electronic tags support built-in batteries, passive radio frequency tags do not support built-in batteries, and special parts of semi-passive tags rely on batteries to work.
Four, the price is different
Active rfid tag: high price and relatively short battery life;
Passive rfid tags: the price is cheaper than active rfid tags, and the battery life is relatively long;
Semi-source rfid tags: relatively moderate price, but relatively few functions.