Active vs. passive RFID tags

Active RFID tags

Active tags comprise an electronic microchip, an antenna, a battery and an integrated transmitter. The integrated transmitter sends energy directly to the reader instead of reflecting the energy transmitted from the reader back to the tag. This makes it possible to achieve a more extensive reading range. In addition to the greater reading distance, active tags support numerous additional functions, such as integrated sensors, an expanded data memory and more logic functions.

Since active tags hold more components and support a variety of additional functions, they normally require more space than the other tag types. The costs for active RFID tags are also higher due to the additional materials and special features. They also have a shorter life span as the transmitter and the additional moving parts require more power.

Active RFID tags are mainly suitable for processing valuable goods which require uninterrupted real-time tracking and/or monitoring of the surroundings.

Passive RFID tags

As described above, passive tags are made up of two parts: an electronic microchip and an antenna. They do not contain any other moving parts or batteries. Power is supplied to the tags during reading via a so-called inductive coupling.

Generally speaking, inductive coupling works as follows: If the reader/the antenna and the tag are in the same reading range, the reader/the antenna generates a magnetic field which triggers a coupling of the tag and reader. During coupling, power from the reader is transmitted through the tag’s conductive antenna and onto the tag itself, thus making it possible to read the data saved on it.

Due to the fact that the tags are only operated when needed, they mostly have a long and stable lifetime. The fact that they do not include any moving parts reduces their probability of failure.

Their long life span and high reliability make passive RFID transponders inexpensive and particularly suitable for long-term warehouse applications. They are useful when the labeled goods do not need to be tracked for a long time.