IDENTIFICATION TRANSPONDER

摘要

An identification transponder (IDT) for transferring an identification code (IDC) to a base station (BS) by means of varying an RF-signal transmitted by the base station (BS) in a rhythm which corresponds to the identification code (IDC). The identification transponder (IDT) comprises means (IDCG) for the generation of the identification code (IDC); rectifying means (RTF); and a load transistor (TL). The load transistor (TL) is arranged in such a manner that it performs two tasks: the task of rectifying the RF-signal (thus it substitutes a diode function in the rectifying means (RTF)), and the task of supplying a variable load to the rectifying means (RTF). The variable load varies in said rhythm. As a consequence the input current of the rectifying means (RTF) is varied in said rhythm which in turn varies the RF-signal. This variation in the RF-signal is detected in the base station (BS). The coupling between the identification transponder (IDT) and the base station (BS) can be performed by capacitive coupling means (P1;P3, P2;P4) or by inductive coupling means. Thanks to the twofold function performed by the load transistor (TL), a diode function of the rectifying means (RTF) is saved. This is especially advantageous if the electronic components of the identification transponder (IDT) are constructed from organic materials (for example polymeric materials).