| 摘要 |
2128431 9314478 PCTABS00024 The invention relates to a method and a device for remote sensing of objects, said method including the steps of marking said objects with at least one label (10) comprising at least one electrical resonant circuit (14) having an induction means (11) and a capacitor means (12), exciting said resonant circuit (14) to resonance at a resonant frequency, and detecting said resonant frequency of said resonant circuit (14) by the electromagnetic energy transmitted from said resonant circuit (14). An element (13) of a magnetic material having a varying permeability is coupled inductively to said induction element (11). The resonant frequency of said resonant circuit (14) is affected by the permeability of said element (13) of magnetic material, and said element (13) of magnetic material is exposed to an external and spacially heterogenous magnetic bias field through which the permeability of said element (13) of magnetic material is controlled. The invention relates also to methods for coding labels and for noise suppression of signals received from said labels.
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