Signal reception arrangement using passive transponder

摘要

A probe (10) transmits an excitation signal at one frequency from a first coil (20) wound on the ferrite rod (14), and receives the response at another frequency in close proximity which is picked up by a second coil (22) at the other end. Centrally on the rod (14) a sec. coil (34) tuned (46) to the transmission frequency is wound on a prim. coil (40) having about 17 times as many turns.