ENCAPSULATED ANTENNA IN PASSIVE TRANSPONDERS

摘要

A passive transponder comprises an antenna (1, 2) in the form of a metal bod y with two main surfaces and a diode (3) connected between the main surfaces and a dielectric (10) surrounding the antenna. A characteristic of the invention is that the impedance of the antenna is adapted to the impedance of the diod e by matching unit (13, 14). A transmission line (8) is used as the matching unit. Another characteristic for the invention is that the transmission line is surrounded by a dielectric (10) made of plastic. Yet another characteristic of the invention is that the antenna is surrounded by a dielectric made of plastic which reduces the influence of the surroundings on the near field of the antenna.