Givare, metod och system för fjärrdetektering av föremål

摘要

The respective sensor element is momentarily exposed to resulting magnetic field without magnetic-invariant component. The orientation of that sensor element is determined from orientation of magnetic-invariant component of magnetic field (Hbias) when frequency shift occurs. The electromagnetic signals are generated by magnetic elements for exciting sensor elements provided at each object (20). An electromagnetic reply signal is generated from each sensor element, that is modulated by magnetic field (Hmod) having magnitude-variant (AC) and magnitude-invariant (DC) component. The magnetic field (Hbias) with rotating field vector is generated to detect frequency shift in component of reply signal when magnitude-invariant component of magnetic field (Hbias) balances the magnetic-invariant component of magnetic field (Hmod). Independent claims are also included for the following: (a) sensor; (b) remote detection system of objects