Automatic vehicle identification technology and applications

A vehicle identification system which uses RF techniques in the near-microwave region has application to a variety of transportation modes, including bus, truck, and rail. The system includes an active reader, a transmit/receive antenna and a series of uniquely encoded tags. An attractive feature of the tag is that it requires no direct power supply, as power is derived from the radiated RF energy of the reader. The system is being used in rail car, truck and automobile identification and bus vehicle location applications.