RFID electronic tags can also be divided into active and passive categories according to the way they communicate with the reader. All passive RFID electronic tags can work without power. Active RFID electronic tags have a power source that can enhance signal transmission between readers. Active RFID electronic tags are used to identify pallets and trams, enabling the reading distance to reach tens of meters. When using passive RFID electronic tags, the reading distance is a few centimeters to fifteen meters. Compared with active RFID electronic tags, passive RFID electronic tags have the advantages of low price and long service life, while the service life of active RFID electronic tags depends on the power supply.
Passive RFID electronic tags will not independently send any signals. The reader interrogates the passive RFID electronic tag through induction. Passive RFID tags only work if they are close enough to a reader that can read a specific frequency band. The reader sends the data obtained from the RFID electronic tag to the system for identity verification.
Recognition technology and its application
According to its operating frequency, passive identification technology is usually divided into 125 kHz, 13.56 MHz and UHF technology. These technologies are standardized (so-called open technologies) or proprietary (so-called closed technologies). When you decide to expand your system with compatible readers and RFID readers in the future, open and standardized technologies, such as smart card technology MIFARE® and UHF technology EPC, can provide you with more supplier choices. On the contrary, closed technology means that only one supplier can provide you with compatible readers and RFID readers.
Using passive UHF technology, the recognition distance ranges from a few meters to more than ten meters. UHF technology is used in vehicle identification and logistics applications. It is also suitable for personnel identification in the following applications: a person carrying an RFID electronic tag passes through a designated place without displaying the RFID electronic tag near the reader.
125 kHz and 13.56 MHz provide a recognition distance of several centimeters. These techniques are used for access control and asset tagging.