Abstract: A reflector is constituted by a right pseudo-dihedral, a ridge (C) of which is in the form of a portion of a helix so as to provide a calibrator or a beacon.

Abstract: By associating an open conductive shield with a radiating loop, it is possible to limit transmission of the electric field for the benefit of transmission of a magnetic field alone. It is shown in particular in the nuclear magnetic resonance imaging field that the antenna becomes less sensitive to the dielectric behavior of the zone in which the emitted field is radiated.

Abstract: An antenna for nuclear magnetic resonance imaging devices has two electromagnetic circuits connected to each other so as to produce mutual opposition of their electromotive force when they are placed in a uniform electromagnetic induction field. It is considered that a localized transmitter does not produce a uniform field. This antenna therefore makes it possible to detect this field if it comes close to this latter. On the other hand, this antenna does not present any reactive field to a transmitter in which it may be considered that the field opposite to said antenna is uniform.