Designs for ATDRSS tri-band reflector antenna

An approach to designing a triband reflector antenna is described. In this approach, three separate feeds are used. This allows each feed to be optimized for a single band. The feeds are isolated by means of frequency-selective surfaces (FSS). The FSS will transmit certain frequencies while reflecting others. Conventionally, most FSS are designed to be used in two frequency bands. The challenge is to design an FSS that works for three bands (e.g., transmitting two bands and reflecting a third). Two reflector antenna configurations are presented, an offset single reflector and a symmetric-shaped dual reflector. The offset fed single reflector antenna configuration has been selected for integration into proposed ATDRSS (Advanced Tracking and Data Relay Satellite System) designs. CADAM drawings have been completed for the design concept and a 1/13th scale model has been constructed, using this offset-fed antenna configuration. This design is shown to meet the original ATDRSS single-access antenna pointing requirements.>