Method of cutting antenna mesh

Abstract

An open mesh material for use as a high performance RF reflective antenna surface and which is formed as a Leno type weave using electrically conductive composite yarns which have a construction for avoiding loose metal-to-metal contacts which generate undesirable passive intermodulation products (PIM). The composite yarns are formed by counter-wrapping stretch resistant nonconductive strands about an insulated metal strand and a stretch resistant nonconductive filler yarn. The insulated metal strand preferably includes a beryllium-copper wire which is encapsulated within a polyamide coating. The woven mesh is coated with a RF energy transparent silicone-based paint to provide additional insulation to the plastic coated wires at the weave junctions and has a surface resistivity sufficiently low to facilitate bleed off of building electro-static charges. A method for cutting the mesh material into gore shaped reflector panels is also disclosed whereby the cut strands of the mesh panels are kept at a minimum distance spacing away from one another so as to prevent the formation of loose metal-to-metal contacts known to cause PIM. An improved PIM free method of attaching the gore shape mesh panels to the ribs of a reflector is also disclosed. The attachment method includes bonding the adjoining side edge margins of adjacent gore shape mesh panels in an over and underlapping fashion to an intermediate doubler mesh material which, in turn, is sewn directly to the ribs.