Frequency-hopping for passive and semi-passive telemetry and identification systems

摘要

By using frequency-hopping in the reader of a passive transponder or tag system, most interferences between readers caused when several readers are used in a limited space may be eliminated. The known frequency-hopping process may be used in passive telemetry transponders or tags for identification systems so that at the passive side only a large-band antenna and a large-band HF rectifier are needed. All supplementary circuits are located in the reader and process there the base band signal. This narrow-band signal may be easily processed by a digital signal processing technique.