Abstract: There is disclosed herein a waveguide rotator for use with a dual polarization waveguide probe system. The waveguide has an internal structure that protrudes into the waveguide such that a first orthogonal component of the incident polarized signal propagates to the end of the waveguide and is reflected therefrom and the second orthogonally polarized component is cut-off by the protruding structure which narrows the waveguide, at a distance from a short circuit at the end of the waveguide, and is reflected substantially at the cut-off point, the cut-off point being frequency dependant. At some predetermined distance from the reflecting means and the cut-off point, the first component and the second component are recombined such that the polarization of the recombined structure is rotated 90° from the incident polarization. The protruding interior surface creates a pocket or cavity behind the waveguide into which components from a circuit board can be inserted.

Abstract: A waveguide for use with a dual polarization waveguide probe system is described which provides an improved frequency response across a desired frequency range (10.7 to 12.75 GHz) and particularly at the band edges. This is achieved by providing a waveguide with a rotator that incorporates a reflector plate in combination with a differential phase shifter in the form of a waveguide of slightly asymmetrical cross section so that orthogonal signals which travel through this portion have a different cut-off wavelength. This results in a rotator which achieves 180° of phase shift between two orthogonal components across the frequency range of signals received by the waveguide. The reflector plate and the differential phase shifter have inverse frequency characteristics so that the combined phase shift characteristic of the rotator has a flatter frequency characteristic.

Abstract: A waveguide for use with a dual polarization waveguide probe system is described which provides an improved frequency response across a desired frequency range (10.7 to 12.75 GHz) and particularly at the band edges. This is achieved by providing a waveguide with a rotator that incorporates a reflecting plane in combination with a differential phase shift portion in the form of a waveguide of slightly asymmetrical cross section so that orthogonal signals which travel through this portion have a different cut-off wavelength. This results in a rotator which achieves 180° of phase shift between two orthogonal components across the frequency range of signals received by the waveguide. The reflecting plate and the differential phase shift portion have inverse frequency characteristics so that the combined phase shift characteristic of the rotator has a flatter frequency characteristic.

Abstract: There is disclosed herein a waveguide rotator for use with a dual polarization waveguide probe system. The waveguide has an internal structure that protrudes into the waveguide such that a first orthogonal component of the incident polarized signal propagates to the end of the waveguide and is reflected therefrom and the second orthogonally polarized component is cut-off by the protruding structure which narrows the waveguide, at a distance from a short circuit at the end of the waveguide, and is reflected substantially at the cut-off point, the cut-off point being frequency dependant. At some predetermined distance from the reflecting means and the cut-off point, the first component and the second component are recombined such that the polarization of the recombined structure is rotated 90° from the incident polarization. The protruding interior surface creates a pocket or cavity behind the waveguide into which components from a circuit board can be inserted.

Abstract: A dual circular polarization waveguide (24) is described which has a septum (36) which divides the waveguide (24) into two separate compartments (38, 40) each with a probe (30A, 30B) passing through the end wall (32) of the waveguide (24) into the compartment (38, 40) to detect respective signals in each of the compartments (38, 40). The septum (36) is proportioned and dimensioned to convert the left and right circularly polarized signals, into substantially linearly polarized signals as the signals pass along the waveguide (24) past the septum (36) so as by the time the signals reach the probes (30A, 30B) they are linearly polarized. The probes (30A, 30B) which pass through the rear wall (32) of the waveguide (24) are oriented such that they couple into the magnetic field of the primary or fundamental waveguide mode.

Abstract: The present invention relates to antenna feeds (10, 30, 70, 78, 94) for use in linear or circularly polarised systems. In one embodiment of the invention, a cross-type antenna feed (30) comprises a cylindrical metal waveguide housing (12) and a cross-type metal feed body (32) coupled to the front of the waveguide housing (12). The feed body (32) has four peripherally spaced corrugated arm portions (34) arranged in a mutually orthogonal relationship, where the arm portions (34) extend radially outwardly from a longitudinal axis (16) of the feed body (32). Ridges (36) on each arm portion (34) are arranged concentrically around the axis (16) and parallel thereto, with successive ridges spaced from the axis (16) in a tiered arrangement. In another embodiment the antenna feed is a dielectric lens. The antenna feed is used in an antenna system having a reflector antenna in addition or in a low noise block (LNB) receiver.

Abstract: A waveguide for use with a dual polarization waveguide probe system is described which provides an improved frequency response across a desired frequency range (10.7 to 12.75 GHz) and particularly at the band edges. This is achieved by providing a waveguide with a rotator that incorporates a reflecting plane in combination with a differential phase shift portion in the form of a waveguide of slightly asymmetrical cross section so that orthogonal signals which travel through this portion have a different cut-off wavelength. This results in a rotator which achieves 180° of phase shift between two orthogonal components across the frequency range of signals received by the waveguide. The reflecting plate and the differential phase shift portion have inverse frequency characteristics so that the combined phase shift characteristic of the rotator has a flatter frequency characteristic.

Abstract: There is disclosed herein a waveguide rotator for use with a dual polarization waveguide probe system. The waveguide has an internal structure that protrudes into the waveguide such that a first orthogonal component of the incident polarized signal propagates to the end of the waveguide and is reflected therefrom and the second orthogonally polarized component is cut-off by the protruding structure which narrows the waveguide, at a distance from a short circuit at the end of the waveguide, and is reflected substantially at the cut-off point, the cut-off point being frequency dependant. At some predetermined distance from the reflecting means and the cut-off point, the first component and the second component are recombined such that the polarization of the recombined structure is rotated 90° from the incident polarization. The protruding interior surface creates a pocket or cavity behind the waveguide into which components from a circuit board can be inserted.

Abstract: A multi-frequency antenna feed for incorporation into a single unit which combines at least two waveguides to provide simultaneous reception and/or transmission of signals in at least two separate frequency bands is described. This is achieved by creating a waveguide system of at least two waveguides sharing the same central axis; a central conventional waveguide which also acts as a center conductor for an outer coaxial waveguide and feeding the outer coaxial waveguide from a non-circular side feed, orthogonal to the waveguide axis, to set up a uniform field in the outer coaxial waveguide. The feeds are adjusted so that the phase center for each frequency band is at the same point in the feed for the same dish. Various embodiments of the invention are described.

Abstract: The present invention relates to antenna feeds (10, 30, 70, 78, 94) for use in linear or circularly polarised systems. In one embodiment of the invention, a cross-type antenna feed (30) comprises a cylindrical metal waveguide housing (12) and a cross-type metal feed body (32) coupled to the front of the waveguide housing (12). The feed body (32) has four peripherally spaced corrugated arm portions (34) arranged in a mutually orthogonal relationship, where the arm portions (34) extend radially outwardly from a longitudinal axis (16) of the feed body (32). Ridges (36) on each arm portion (34) are arranged concentrically around the axis (16) and parallel thereto, with successive ridges spaced from the axis (16) in a tiered arrangement. In another embodiment the antenna feed is a dielectric lens. The antenna feed is used in an antenna system having a reflector antenna in addition or in a low noise block (LNB) receiver.

Abstract: The present invention relates to antenna feeds (10, 30, 70, 78, 94) for use in linear or circularly polarized systems. In one embodiment of the invention, a cross-type antenna feed (30) comprises a cylindrical metal waveguide housing (12) and a cross-type metal feed body (32) coupled to the front of the waveguide housing (12). The feed body (32) has four peripherally spaced corrugated arm portions (34) arranged in a mutually orthogonal relationship, where the arm portions (34) extend radially outwardly from a longitudinal axis (16) of the feed body (32). Ridges (36) on each arm portion (34) are arranged concentrically around the axis (16) and parallel thereto, with successive ridges spaced from the axis (16) in a tiered arrangement. In another embodiment the antenna feed is a dielectric lens. The antenna feed is used in an antenna system having a reflector antenna in addition or in a low noise block (LNB) receiver.