Abstract: An antenna device includes a radiating structure configured to transmit and/or receive electromagnetic waves in a first direction, and a lens substrate spaced from the radiating structure in the first direction and including an aperture therein aligned, at least in part, with the radiating structure along the first direction and a surface having conductive material thereon configured to apply a phase shift to electromagnetic waves to and/or from the radiating structure passing therethrough. Some embodiments include multiple lens substrates spaced from one another and from the radiating structure, each lens substrate having an aperture therein aligned at least in part with the radiating structure along the first direction and a surface having conductive material thereon. In some embodiments, the aperture is aligned in part with the radiating structure along the first direction and is offset from the radiating structure in a direction perpendicular to the first direction.

Abstract: An antenna includes a radiating structure to radiate electromagnetic waves having a phase along a radiating path extending in an axial direction, and a lens disposed in the radiating path and configured to pass the electromagnetic waves therethrough. The lens includes at least one lamina having a first surface, a second surface, a center axis that is aligned with the axial direction, a lamina thickness between the first surface and the second surface in a direction parallel to the axial direction, and an axial region extending about the center axis. Conductive scattering elements are arranged on the first surface, the second surface or both the first surface and the second surface. The conductive scattering elements are configured to change a first phase of the electromagnetic waves passing through the plurality of conductive scattering elements with respect to a second phase of the electromagnetic waves passing through the axial region.

Abstract: A folded-waveguide slow-wave structure equipped with an internal load, includes a central plate comprising a rectilinear beam tunnel of same direction as the longitudinal axis of the central plate, and a serpentine-shaped folded slit having its folds in the direction of the width of the waveguide; a lower plate and an upper plate closing the waveguide, the plates being placed on and under the central plate, respectively; at least one groove of cross section that may be variable, produced along the longitudinal axis of the waveguide, in at least one face internal to the waveguide of the lower plate, the upper plate or the central plate, and at least partially comprising a lossy material; in order to form a closed slow-wave structure through which propagates a hybrid slow wave the amplitude of which is attenuated by at least 20 dB between the start and the end of the portion of the one or more grooves containing a lossy material.

Abstract: A folded-waveguide slow-wave structure equipped with an internal load, includes a central plate comprising a rectilinear beam tunnel of same direction as the longitudinal axis of the central plate, and a serpentine-shaped folded slit having its folds in the direction of the width of the waveguide; a lower plate and an upper plate closing the waveguide, the plates being placed on and under the central plate, respectively; at least one groove of cross section that may be variable, produced along the longitudinal axis of the waveguide, in at least one face internal to the waveguide of the lower plate, the upper plate or the central plate, and at least partially comprising a lossy material; in order to form a closed slow-wave structure through which propagates a hybrid slow wave the amplitude of which is attenuated by at least 20 dB between the start and the end of the portion of the one or more grooves containing a lossy material.