DEVICE FOR MEASURING ELECTROMAGNETIC RESPONSE FROM PLANE-PARALLEL PLATES IN THE MICROWAVE RANGE Russian patent published in 2021 - IPC G01R27/26 

FIELD: electromagnetic response measuring.

SUBSTANCE: invention is intended for measuring the electromagnetic response from plane-parallel plates. The substance of the invention lies in the fact that a device for measuring the electromagnetic response from plane-parallel plates contains a unit for generating and displaying a microwave signal, two lens waveguides formed by flat phase-inverted diffractive optical elements of the corresponding range L1, L3 and L2, L4, a radiating horn located in the front focal lens plane L1, and a receiving horn located in the rear focal plane of the lens L2, a diaphragm made of radio-absorbing material, a focusing lens L3 located in the front focal plane L1, and a focusing lens L4 located in the front focal plane of the lens L2, with the aperture located in the rear focus relative to lens L3 and in front focus relative to lens L4, characterized in that the diffractive optical elements L3 and L4 consist of a substrate transparent for the radiation used, on the surface of which a phase-inverted structure with the boundaries of Fresnel zones is placed, the substrate is made in the form of a truncated cone with a cone height approximately equal to the focal length of the diffractive optical element, with the ratio the radii of the lower and upper bases of the truncated cone, approximately equal to 2, and with the refractive index of the material not less than the refractive index of the material of the phase-inverted structure, directed by the smaller base towards the focusing region of the radiation, and the focal length is selected no more than the wavelength of the radiation used and the irradiation of the diffractive optical element is carried out from the side of the phase-inverted structure.

EFFECT: increasing the spatial resolution to the subwavelength level.

1 cl, 2 dwg