Definition[]
An electronic tracking device (also called a transponder) is a one-way radio communication device that emits a signal on a specific radio frequency. This signal can be received by special tracking equipment, and allows the user to track the geographical location of the transponder.
Overview[]
Such "homing" devices are used by law enforcement personnel to keep track of the physical whereabouts of the sending unit, which might be placed in an automobile, on a person, or in some other item.