Method for tuning an antenna resonant circuit of a passive transponder

Abstract

In the previously known methods for tuning the antenna resonant circuit, in the case of passive transponders, their range in a high-frequency carrier field is generally limited to a few cm as the supply voltage for the integrated circuit gained from the carrier field falls very quickly with increasing distance. According to the new method, the range of passive transponders in a high-frequency electromagnetic carrier field is substantially increased, in that the real and imaginary parts connected to the contact surface of the antenna contact are minimized and the energy absorbed from the carrier field by means of a serial resonant circuit is used to the greatest possible extent for generating the supply voltage for the integrated circuit of the transponder.

Dependencies are inferred from the claim text.