Cost Disruptive Reflector Surface for Large Deployable Antennas

Abstract

Current flight solutions for Large Deployable Antennas (LDA) most commonly employ the use of highly flexible metal wire knitted meshes as a reflector surface material. These surfaces, also known as ‘tricot meshes’, are normally realized using gold plated molybdenum and tungsten wires and require tensioning in the range of 5-10g/cm to obtain sufficient electrical contact between wires and to reduce surface RMS deformation to an acceptable level. The cell or facet size of a knitted mesh is determined by the operating frequency; the higher the frequency the higher the cell density required. Meshes are well known for lower frequency (L and S-band) applications but the challenges of operating LDAs at desired higher frequencies (Ka-band) means metal mesh surfaces require increasingly complex cable tensioning nets and a deviation away from proven mesh materials. High frequency operation of metal meshes also increases the likelihood of Passive Intermodulation (PIM) occurring and thus a degradation in the performance of the antenna.