Abstract: An antenna device including: a first antenna assembly configured to receive first radiofrequency signals polarized according to a first polarization; a second antenna assembly configured to receive second radiofrequency signals polarized according to a second polarization orthogonal to the first polarization; and a radiofrequency signal handling assembly coupled with the first and second antenna assemblies, and configured to handle the received first radiofrequency signals separately from the received second radiofrequency signals.

Abstract: An antenna device including: a first antenna assembly configured to receive first radiofrequency signals polarized according to a first polarization; a second antenna assembly configured to receive second radiofrequency signals polarized according to a second polarization orthogonal to the first polarization; and a radiofrequency signal handling assembly coupled with the first and second antenna assemblies, and configured to handle the received first radiofrequency signals separately from the received second radiofrequency signals.

Abstract: A tunable delay line for radiofrequency applications includes a waveguide and a dielectric perturbing member that is displaceable relative to the waveguide for varying the delay imparted by the line. The waveguide is a ridge waveguide and the perturbing member is arranged parallel to a longitudinal end surface of the ridge and is movable in the ridge plane, toward and away from the ridge end surface, or in a direction transversal to the ridge.

Abstract: A forehearth (1) or working-end for glass furnace of the type including one or more modules or sections (2), each one having: —an understructure (3) in which a vat (4) is defined into which the molten glass flows; —a superstructure (5) including a cooling air duct (13) and a pair of lateral fume ducts (20), communicating with the vat area (4) into which the molten glass flows, characterised in that, next to an outlet opening (17) of the duct (13), a “Venturi block” (22) is provided, into which both the cooling air from the duct (13) and the fumes from the fume ducts (20) flow, shaped in such a way that the cooling exit air causes the fumes to be extracted from the fume ducts (20). The forehearth and the fume extraction procedure enable the thermal homogeneity of the glass to be improved while reducing the use of refractory material, the formation of cracks in the superstructure and costs.

Abstract: A tunable delay line for radiofrequency applications includes a waveguide and a dielectric perturbing member that is displaceable relative to the waveguide for varying the delay imparted by the line. The waveguide is a ridge waveguide and the perturbing member is arranged parallel to a longitudinal end surface of the ridge and is movable in the ridge plane, toward and away from the ridge end surface, or in a direction transversal to the ridge.

Abstract: In an induction furnace for the synthesis of glasses, in particular fluorozirconate glasses for optical fibres for telecommunications, the support device (6') for the crucible (3) is associated with a pair of sleeves (7, 9) between which an annular element (8) which constitutes the actual support element is inserted. The first sleeve (7) has such longitudinal dimensions that the crucible (3) is supported in the annular element (8) in such a way as to be spaced from the planar element (5'), and the second sleeve has such longitudinal dimensions that its top edge is at a level higher than that of the top edge of the crucible (3), to obtain a homogeneous temperature region extending at least along the entire height of the crucible (3).

Abstract: An active single-mode optical fiber has the core made of a rare earth doped non-oxide glass and the cladding made of an oxide glass. The glass of the core has a melting temperature lower than that of the glass of the cladding and lying within the range of the softening temperatures of the latter. In a preferred embodiment the core is made of a chalcogenide glass and the cladding is made of a lead silicate glass. To produce the fiber, a preform, obtained by introducing an element made of the non-oxide glass into the hole of a capillary tube made of the oxide glass, is brought to a temperature lying within the range of softening temperatures of the oxide glass and not lower than the melting temperature of the non-oxide glass, and is drawn. The capillary tube, during the drawing process, serves as a container for the molten glass of the core.

Abstract: Fluoride glass optical fibers are fabricated by minimizing the number of high-temperature operations. A tube comprising an external layer of a first fluoride glass of composition suitable to form the cladding of the fiber and an internal layer of a second fluoride glass of composition suitable to form the core of the fiber is prepared by a conventional rotational casting technique. Then, the internal layer is thinned by means of chemical etching at ambient temperature until the attainment of a ratio between the volumes of the two layers that corresponds to the ratio between the core and cladding diameters required for a single mode fiber, and the resulting tube is drawn.

Abstract: Refractive index change in a glass substrate, necessary to obtain a guiding region, is obtained by bombarding the substrate surface with an electron beam. An electric field induced by negative charge accumulation is created under the surface, whereby sodium ions present in glass are made to migrate towards the inside of the substrate.

Abstract: Detection system for cathodoluminescence analysis apparatus, wherein a screen is placed between the sample to be analyzed and the detector to intercept the electrons backscattered by the sample towards the detector. The screen is a plate of a glass which is transparent in a wide spectral interval, has a rather high conductivity, and does not present cathodoluminescence effects.

Abstract: Integrated optical guides are fabricated on fluoride glass plates by expog such plates to an atmosphere of a gaseous halogen other than fluorine, or of a compound capable of generating such a halogen, at high temperature and pressure, so as to obtain a ion exchange between fluoride ions in the glass and halide ions.