Reflector antenna adapted for use on a mobile platform, comprising: a main reflector having an aperture at its axial center; a subreflector spaced forwardly of said main reflector; a support structure for supporting said subreflector fixedly relative to said main reflector; a feed horn disposed within said aperture such that a first portion of said feed horn projects forwardly of said main reflector and a second portion of said feed horn projects rearwardly of said main reflector, a rotary joint suitable for placement on an exterior surface of said mobile platform for rotating the aperture along an azimuthal axis,further a first antenna signal processing subsystem, suitable for placement closely adjacent to said main reflector exteriorly of said mobile platform, for processing at least one of signals sent to or received by said feedhorn; and a second antenna signal processing subsystem, suitable for placement interiorly of said mobile platform, for processing at least one of signals sent to or received by said first antenna signal processing subsystem; wherein the rotary joint facilitates bi-directional communication between the first antenna signal processing subsystem and the second antenna signal processing subsystem, wherein said first antenna signal processing subsystem comprises an ortho mode transducer in communication with said feedhorn for splitting a signal received by said feedhorn into vertically and horizontally polarized signals, wherein said first antenna signal processing subsystem further comprises: a vertical polarization signal processing subsystem in communication with said ortho mode transducer for processing vertically polarized signals communicated to or received from said ortho mode transducer; and a horizontal polarization signal processing subsystem in communication with said ortho mode transducer for processing horizontally polarized signals communicated to or received from said ortho mode transducer, wherein said first antenna signal processing subsystem comprises two pairs of diplexers (42,48,52,58) for splitting transmit and receive signals being communicated to and from said first antenna signal processing subsystem, wherein said first antenna signal processing subsystem comprises at least one low noise amplifier for amplifying signals received by said feedhorn. a main reflector having an aperture at its axial center; a subreflector spaced forwardly of said main reflector; a support structure for supporting said subreflector fixedly relative to said main reflector; a feed horn disposed within said aperture such that a first portion of said feed horn projects forwardly of said main reflector and a second portion of said feed horn projects rearwardly of said main reflector, a rotary joint suitable for placement on an exterior surface of said mobile platform for rotating the aperture along an azimuthal axis,further a first antenna signal processing subsystem, suitable for placement closely adjacent to said main reflector exteriorly of said mobile platform, for processing at least one of signals sent to or received by said feedhorn; and a second antenna signal processing subsystem, suitable for placement interiorly of said mobile platform, for processing at least one of signals sent to or received by said first antenna signal processing subsystem; wherein the rotary joint facilitates bi-directional communication between the first antenna signal processing subsystem and the second antenna signal processing subsystem, wherein said first antenna signal processing subsystem comprises an ortho mode transducer in communication with said feedhorn for splitting a signal received by said feedhorn into vertically and horizontally polarized signals, wherein said first antenna signal processing subsystem further comprises: a vertical polarization signal processing subsystem in communication with said ortho mode transducer for processing vertically polarized signals communicated to or received from said ortho mode transducer; and a horizontal polarization signal processing subsystem in communication with said ortho mode transducer for processing horizontally polarized signals communicated to or received from said ortho mode transducer, wherein said first antenna signal processing subsystem comprises two pairs of diplexers (42,48,52,58) for splitting transmit and receive signals being communicated to and from said first antenna signal processing subsystem, wherein said first antenna signal processing subsystem comprises at least one low noise amplifier for amplifying signals received by said feedhorn. a vertical polarization signal processing subsystem in communication with said ortho mode transducer for processing vertically polarized signals communicated to or received from said ortho mode transducer; and a horizontal polarization signal processing subsystem in communication with said ortho mode transducer for processing horizontally polarized signals communicated to or received from said ortho mode transducer, wherein said first antenna signal processing subsystem comprises two pairs of diplexers (42,48,52,58) for splitting transmit and receive signals being communicated to and from said first antenna signal processing subsystem, wherein said first antenna signal processing subsystem comprises at least one low noise amplifier for amplifying signals received by said feedhorn.