摘要:
A groundstation antenna comprises a body 1 of a foamed plastics material having on a rear parabolic surface a metallised coating (3) providing a main reflecting surface. A front surface of the body (1) has on a hyperbolic surface a metallised coating (2) providing a sub-reflector. A feed horn is received within a rear recess (4) in the body 1. The main reflector and the sub reflector are thus accurately located with respect to one another and protected from the weather. In an alternative embodiment (Figure 7), two casing members are joined at their outer peripheries to form an antenna of enclosed, hollow shell-like form.
摘要:
Le procédé consiste : - à définir (100) au moins un objectif de performances de rayonnement à réaliser sur une zone de couverture au sol choisie, - à réaliser (200) une coque rigide (11) ayant un profil de forme prédéfinie - à réaliser la membrane flexible (12), - à déterminer (300), par itérations successives, à partir d'un modèle mécanique du réflecteur et d'un modèle de rayonnement radiofréquence de l'antenne, N déformations locales (14) optimales à appliquer en N points différents de la membrane flexible, - à réaliser (400) N barres de maintien (13) rigides de longueurs fixes différentes correspondant aux déformations locales optimales à appliquer à la membrane flexible, - à positionner et fixer (500) rigidement la membrane flexible (12) sur la coque rigide (11) par l'intermédiaire des N barres de maintien (13).
摘要:
The invention relates to a process for improving the reflectivity of reflective surfaces (1) of antennas, said reflective surfaces (1) being made of a composite, comprising at least one layer of composite (2), characterized in that it comprises the following steps: a) laminating a layer of plastic (3) comprising a metallization layer (4) on the at least one layer of composite (2), bonding the metallization layer (4) to the substrate of the layer of composite (2) in its preimpregnated state by means of the resin itself of the composite; b) cutting the assembly of the layer of composite (2) and the layer of plastic (3) comprising a metallization layer (4); c) forming strips or patterns with a determined shape from the assembly formed by the layer of composite (2) and the layer of plastic (3) comprising a metallization layer (4) of step b); d) laminating the strips or patterns of step c) as a first layer on a molding jig; e) preparing the vacuum and curing bag; f) introducing in the autoclave; g) performing the curing cycle, in which the resin of the composite, upon polymerizing, bonds the layer of plastic (3) comprising the metallization layer (4) to the rest of the substrate of the layer of composite (2).
摘要:
The invention concerns a method for producing electrically conductive patterns on a non-developable surface of an insulating substrate, and the resulting device. The invention is characterized in that it consists in: coating the non-developable surface (6) uniformly with a layer of electrically conductive material (9), which is in turn coated with a layer of protective material (10), and then, using a mobile laser head, eliminating by laser ablation the portions of said protective substance layer (10) which do not cover said electrically conductive patterns, then eliminating the portions of said electrically conductive material (9) exposed by the elimination of said portions of said protective material layer (10)
摘要:
Disclosed is a composite material adapted for mechanical fastener use as the loop component complementary to a hook component. The composite material is made by laminating a film (10, 116) with an amorphous polymer layer to a prebonded nonwoven web (30, 114), using a bond pattern different from the pattern on the nonwoven so as to provide loose filaments or fibers between the laminate bond points. Desirably, the composite also has a MVTR of at least about 100 g/m2/24 hours and a hydrohead of at least about 50 mbar. In use as a component of a disposable personal care product such as a disposable diaper, the loop fastener component may be substantially the entire backing to provide comfort, protection and highly variable fit.
摘要:
The invention relates to an improved reflector for an antenna, in particular for a mobile radio antenna, characterised as follows: the reflector (1) consists of at least two combined or combinable reflector modules (3); the reflector module (3) is produced in a casting process, a deep-drawing or embossing process, or a milling process and comprises two one-piece interconnected longitudinal walls (5) and at least one transversal wall (7), preferably two transversal walls (7), whose front faces lie against one another at an offset and at least one transversal strut (9) running transversally to the longitudinal walls (5); and a retaining and/or fixing device (27) is provided on the front face of the transversal wall or walls (7) for fixing a second reflector module (3), the two reflector modules (3) being interconnectable in a fixed manner.
摘要:
Curved surfaces particularly reflectors such as concave mirror elements for use in astronomical telescopes, solar energy concentrators etc., and methods of forming such surfaces. A rigid body with a curved surface is formed by providing a mould (20) having a curved surface with a curvature opposite to that of the required curved surface, applying a vacuum to the curved surface of the mould to deform a flexible, generally planar member (14) to match the curved surface of the mould and bonding a front surface of a structurally rigid base member (12) to the opposite surface of the planar flexible member while the vacuum is applied. Peripheral casing members (16, 18) may he bonded to the base member. The base member is formed from a rigid, low-density material such as an aluminium or aluminium alloy honeycomb material. The flexible (reflective) member may comprise a thin metallic sheet such as an anodised aluminium alloy sheet, and any casing members may also be of aluminium or aluminium alloy.