Active, semi-passive and passive RFID tags

The RFID can be active, semi-passive and passive. The difference among the three types that the passive do not have internal  power source while the semi-passive and active one have a small battery as power source. The passive tags are activated by the radioactive signals coming from the RFID readers. The electromagnetic field provides energy to activate the tags. On the other hand, the active tag has its own battery to read from and write into the microchip, and forward the information to the RFID reader. Comparing of the two tags, active one is more expensive than the passive one, but it has a higher reading rage. The active tag has approximately 100 meters range and battery life more than 10 years. Active tags can also store more information, data than the passive one. Active tag has two types: one where the tags respond only when the reader asks, the other gives information periodically. The latter is called as an active beacon tag.

Active tags are used along the sensors that measure humidity, temperature, light radiation and radiation. The following technologies are going to be combined  or used by RFID: Bluetooth, Wi-Fi, GPS, GMS, GPRS and Infrared.

The semi-passive tag has it sown battery power, however, it is usually in sleeping mood. The radio frequency transmitted from readers activates the battery and the tag has the power to read the microchip