There are three types of RFID-tags that are being used today, semi-passive, passive and active ID-tags.
Semi-passive ID-tags (TagMaster)
Semi-passive ID-tags are identified by Readers using backscattering technique. The ID-tag reflects the signal from the Reader along with the data contained in the ID-tag. The semi-passive ID-tags are equipped with batteries only used for powering the electronic processing components of the ID-tag, not for transmission. The batteries inside also keep the ID-tag “awake”, which is why the semi-passive ID-tag is very fast and requires no start-up time. These ID-tags have a fully predictable life time usually on the order of 10 years. The use of semi-passive ID-tags creates a well defined reading zone, long read-range (typically up to 10 metres) and a passage speed of up to 400 km/h.
Passive ID-tags are also identified using backscattering technique. The ID-tag reflects the signal from the Reader along with the data contained in the ID-tag. However, passive ID-tags have no battery and derive all of their operating power from the reader signal, typically resulting in shorter reading ranges than the semi-passive ID-tag and a slower reading process as the tag has to be awaken at reading. Passive ID-tag systems require Readers emitting high output power. The use of passive ID-tags creates a well defined reading zone, shorter read-range (typically up to 3 meters) and a passage speed of up to 30 km/h.
An active ID-tag is battery powered and actively sends out a signal at a pre-set interval or when queried by a Reader. Batteries provide the power for transmission, which imply that these ID-tags have relatively short battery lives. The use of active ID-tags creates a non-defined reading zone, long read-range, and a passage speed of up to 30 km/h.