Patent ID: 6219003
Filing Date: 2001-04-17
Classification: H01Q

Abstract:
A multi-beam satellite antenna for an in-orbit cellular communication system operating at a center wavelength .lambda., comprising:a reflector, said reflector having a concavely curved front reflecting surface, an axis and a focal point;a plurality of microwave feeds, each comprising a conical horn having a predetermined exit diameter for emitting and directing microwave energy onto said reflector, wherein microwave energy incident on said reflector is reflected to thereby produce a corresponding plurality of microwave beams, each of said plurality of microwave beams being associated with a respective one of said plurality of microwave feeds;said reflector including first and second resistive coatings on said concave front reflecting surface and comprising different resistive materials, said first resistive coating defining a first band covering a portion of said front reflective surface;said first band being oriented coaxial of said axis and being located between an outer end edge of said concave front reflecting surface and a recessed position thereof recessed from said outer end edge;said first band being of a predetermined thickness and possessing a tapered resistance, tapered between a minimum resistance at said recessed position and a maximum resistance at said outer end edge;said second resistive coating defining a second band covering a second portion of said front reflective surface;said second band being oriented coaxial of said axis and being located between said recessed position contiguous with an edge end of said first band and a further recessed position, whereby said first and second bands lie side by side;said second band being of a predetermined thickness and possessing a tapered resistance, tapered between a minimum resistance at said further recessed position and a maximum resistance at said recessed position; andsaid microwave feeds being located about said focal point.