A waveguide polarizer for converting between a linearly polarized electromagnetic field in a first waveguide and a circularly polarized electromagnetic field in a second waveguide is provided. The waveguide polarizer includes a structure interconnecting the first and second waveguide which includes a waveguide excitation arrangement with a bifilar helical shape. A circularly polarized antenna arranged to be connected to the first waveguide of the waveguide polarizer and a satellite arrangement are also provided.

An RF joint rotating about an axis of rotation (Z) includes a number N, greater than or equal to 1, of RF transmission channels, a first, internal surface of symmetry of revolution about the axis (Z) and of RF transmission having a first, internal radius r1, and a second, external surface of symmetry of revolution about the axis (Z) and of RF transmission having a second, external radius r2, strictly less than the first, internal radius r1. The first and second RF transmission surfaces facing one another and rotationally mobile about the axis (Z) are configured through the first and second radii r1, r2, the geometry of the first and second RF access ports, and the geometry of the first and second RF containment and guidance means, such that: each RF transmission channel Vi, i varying from 1 to N, comprises a first RF rotating waveguide, and the N first RF rotating waveguides are distributed angularly over a predetermined number NC, greater than or equal to 1 and less than or equal to N, of sections of surfaces of revolution about the axis (Z) of the second RF transmission surface, each of the NC sections being situated along the longitudinal axis of symmetry (Z) at a predetermined different level L1(k).

Parabolic reflector antennas advantageously support low side lobe radiation patterns for ETSI class 4 performance, by utilizing: (i) metal choke plates adjacent a distal end of a dielectric cone within a sub-reflector assembly, (ii) “lossy” material feed boom waveguide sleeves and/or (iii) extended length cylindrical shields lined with radiation absorbing materials. Relatively shallow and large diameter parabolic reflectors having an F/D ratio of greater than about 0.25 may be provided with one or more of the identified (i)-(iii) enhancements.

The described features include a scalable waveguide architecture for a waveguide device. The waveguide device may be split into one or more waveguide blocks instead of manufacturing increasingly larger single-piece waveguide devices. Described techniques provide for a radio-frequency (RF) seal between such waveguide blocks that may facilitate greater manufacturing tolerances while maintaining an effective RF seal at the junction of the waveguide blocks. The described techniques include channels within one or more waveguide blocks opening to the dielectric gap between the waveguide blocks. The channels may, for each of multiple waveguides joined at the interface between waveguide blocks, be included in one or both waveguide blocks and may be in a single waveguide dimension relative to the multiple waveguides, or extend for more than one waveguide dimensions.

A system including an antenna and an ultra-wideband Ortho-Mode Transducer with ridges is provided. The ultra-wideband Ortho-Mode Transducer includes at least at least an ultra-wideband Ortho-Mode Transducer and a radiation antenna, wherein the ultra-wideband Ortho-Mode Transducer comprises a first channel inside, the radiation antenna comprises a second channel inside, a common port of the first channel is connected to a first antenna port of the second channel, a plurality of ridges with a square cross section are arranged in the first channel, and the plurality of ridges arranged in the first channel bulge into the first channel.

The described features include a scalable waveguide architecture for a waveguide device. The waveguide device may be split into one or more waveguide blocks instead of manufacturing increasingly larger single-piece waveguide devices. Described techniques provide for a radio-frequency (RF) seal between such waveguide blocks that may facilitate greater manufacturing tolerances while maintaining an effective RF seal at the junction of the waveguide blocks. The described techniques include channels within one or more waveguide blocks opening to the dielectric gap between the waveguide blocks. The channels may, for each of multiple waveguides joined at the interface between waveguide blocks, be included in one or both waveguide blocks and may be in a single waveguide dimension relative to the multiple waveguides, or extend for more than one waveguide dimensions.

A coaxial feed for multiband antenna for a multiband antenna includes: a tubular high-band (HB) waveguide, the HB waveguide including an outer conducting surface, an inner HB conducting surface, and a HB aperture defined by the inner HB conducting surface; a tubular low-band (LB) waveguide disposed coaxially around the HB waveguide, the LB waveguide including an outer feed surface, an inner LB conducting surface, and an annular LB aperture defined by the inner LB conducing surface and the outer conducting surface of the HB waveguide; and an annular high-band (HB) choke located in the outer conducting surface of the HB waveguide, the HB choke being axially offset from the HB aperture.

According to the present invention, provided is a communication apparatus including a radiation source (10) that radiates an electromagnetic wave, and a first phase control plate (11) that is disposed at a position of a distance L.sub.1 in a radio wave radiation direction from the radiation source (10). In the first phase control plate (11), a phase of a transmitted electromagnetic wave differs according to a distance from a representative point on the first phase control plate (11). The radiation source (10) is able to supply power up to a position separated from the representative point on the first phase control plate (11) by L.sub.1/2.

A variable inclination continuous transverse stub antenna includes a first conductive plate and a second conductive plate spaced relative to the first conductive plate. The first conductive plate includes a first surface partitioned into a first region and a second different region, a first group of CTS radiators on the first region, and a second group of CTS radiators on the second region. A spacing and a width in an E-field direction of the first group of radiators is different in respect to a spacing and width in the E-field direction of the second group of radiators. The second conductive plate includes a second surface parallel to the first surface, the second surface partitioned into a first parallel plate transmission line and a second different parallel plate transmission line, the first and second parallel plate transmission lines configured to receive or output a different radio frequency signals from one another.

An RF joint rotating about an axis of rotation (Z) includes a number N, greater than or equal to 1, of RF transmission channels, a first, internal surface of symmetry of revolution about the axis (Z) and of RF transmission having a first, internal radius r1, and a second, external surface of symmetry of revolution about the axis (Z) and of RF transmission having a second, external radius r2, strictly less than the first, internal radius r1. The first and second RF transmission surfaces facing one another and rotationally mobile about the axis (Z) are configured through the first and second radii r1, r2, the geometry of the first and second RF access ports, and the geometry of the first and second RF containment and guidance means, such that: each RF transmission channel Vi, i varying from 1 to N, comprises a first RF rotating waveguide, and the N first RF rotating waveguides are distributed angularly over a predetermined number NC, greater than or equal to 1 and less than or equal to N, of sections of surfaces of revolution about the axis (Z) of the second RF transmission surface, each of the NC sections being situated along the longitudinal axis of symmetry (Z) at a predetermined different level L1(k).