In this summary of the Active RFID market Dr. Peter Harrop outlines why Active RFID and its associated technologies are receiving such attention and have such high growth predictions.

Passive radar is a term applied to radar that covertly employs other people's emissions as they reveal targets, no signal being emitted by those doing the covert detection. This has military uses. It is not to be confused with Real Time Locating System RTLS using passive tags, a new form of RFID-based RTLS that has burst onto the scene in 2008. This employs passive tags instead of the traditional active tags. The idea is actually about ten years old and it was mooted as a UHF system by Trolleyscan who called it RFID Radar and demonstrated by RFSAW, which uses Surface Acoustic Wave chips that are more sensitive and simpler to make than the silicon chips used by everyone else - active and passive.