The tag is a ceramic cylindrical resonator with an open metallic ring placed on the surface. A chip from a commercial tag is placed in the gap. The reader sends a signal to query the tag, exciting a magnetic dipole mode within it. The induced displacement currents in the resonator are converted into a conductivity current in the ring, initiating the operation of the microchip. The scattered modulated signal follows the reverse path — from conductivity current to radiation in the far field. The magnetic nature of the resonator mode ensures effective coupling with the ring through inductive coupling.