A waveguide structure for a compact and scalable dual-polarized antenna array. In one example, a waveguide device comprises septum polarizers dividing common waveguides into first waveguides associated with a first polarization and second waveguides associated with a second polarization. The sets of septum polarizers may be inverted relative to each other to form first groups of four adjacent first waveguides for each type of waveguide. The waveguide device may also include a waveguide feed network including a first waveguide feed stage including waveguide combiner/dividers coupled between the four adjacent waveguides intermediate waveguides. The waveguide device may further include a second waveguide feed stage coupled with the first intermediate waveguides and the second intermediate waveguides, wherein the second waveguide feed stage extends in a direction perpendicular to the first waveguide feed stage.

Radio-frequency component including several waveguide devices, for example antennas or polarizers, arranged in an array for transmitting and/or receiving electromagnetic signals. The radio-frequency component includes several ridges and each waveguide device includes: at least one inner wall; an upstream opening in the direction of propagation of the signals during emission; and a downstream opening in the direction of propagation of the emitting signals, linked to the upstream opening so that the emitting signals are transmitted from the upstream opening to the downstream opening. The arrangement of the ridges in the openings upstream of the radiofrequency component may be different from the arrangement of the ridges in the openings downstream of the radio-frequency component. The arrangement of ridges in the downstream openings of each waveguide device includes no more and no less than three ridges.

Methods, systems, and devices are described for improving a performance of a waveguide device. A waveguide device that includes a common port and divided ports may also include a sidewall feature that extends across a first set of opposing sidewalls and a second set of opposing sidewalls of the waveguide device. The sidewall feature may have a same shape on each of the first set of opposing sidewalls and a second set of opposing sidewalls. In some cases, the sidewall feature is positioned outside a divided waveguide section of the waveguide device. The position of the sidewall feature may be determined based on an impedance matching metric between the common port and the divided ports, an isolation metric between the divided ports, or both.

Circularly polarized directional antennas and methods of fabrication are provided. An antenna comprises conductive elements above a conductive reflector. The conducting elements are spaced radially outward from the center axis. The elements may be spaced equidistantly about each other or may be spaced between 10 and 80 degrees apart. The elements may be straight or curved. The elements may be a parallel to the reflector or may curve away or toward the reflector. The lengths and widths of each conductive element are adjusted to create or receive a circularly polarized wave of particular rotation based on the location in the element system. The elements are located within a printed circuit board that is bonded to a coaxial cable feedline placed above a metallic reflector. Each conducting element comprises a metallic wire.

A compact radiofrequency driver includes at least one axial port intended to be connected to a radiating antenna, at least one output intended to collect received signals and at least one input intended to transmit signals, comprising first and second septum polarizers and a frequency filter, the second polarizer being connected, via its common port, to a first rectangular port of the first polarizer and the frequency filter being connected to the second rectangular port of the first polarizer and being configured to filter a reception or transmission frequency band, these two bands being different, and wherein at least one of the polarizers is configured to convert a circularly polarized signal received on said axial port of the driver into a linearly polarized signal in a reception frequency band and in that at least a second polarizer is configured to convert a linearly polarized signal transmitted to the driver by the input into a circularly polarized signal in a transmission frequency band.

A waveguide structure for a compact and scalable dual-polarized antenna array. In one example, a waveguide device comprises septum polarizers dividing common waveguides into first waveguides associated with a first polarization and second waveguides associated with a second polarization. The sets of septum polarizers may be inverted relative to each other to form first groups of four adjacent first waveguides for each type of waveguide. The waveguide device may also include a waveguide feed network including a first waveguide feed stage including waveguide combiner/dividers coupled between the four adjacent waveguides intermediate waveguides. The waveguide device may further include a second waveguide feed stage coupled with the first intermediate waveguides and the second intermediate waveguides, wherein the second waveguide feed stage extends in a direction perpendicular to the first waveguide feed stage.

A linear-to-circular polarizer antenna is disclosed. In accordance with embodiments of the invention, the polarizer antenna includes an antenna operable to transmit and receive polarized signals and a linear-to-circular polarizer coupled to the antenna. The polarizer includes a plurality of cascaded elements, waveplates or anisotropic sheets, having biaxial permittivity. Each cascaded element has a principal axis rotated at different angles relative to an adjacent element about a z-axis of a 3-dimensional x, y, z coordinate system, and each element is composed of an artificial anisotropic dielectric. The polarizer further includes impedance matching layers disposed adjacent the cascaded elements.

The invention relates to a radiating element (1) for receiving and transmitting microwave signals in a lower frequency band (RX) and a higher frequency band (TX). The radiating element (1) comprises a septum polarizer (4) for transmitting and/or receiving a frequency band in a first polarization and for transmitting and/or receiving a frequency band in a second polarization that is orthogonal to the first polarization. Waveguides feeding the radiating elements have a fundamental mode cut-off frequency and a higher mode cut-off frequency. The invention proposes to adapt the fundamental mode cut-off frequency and the septum geometry such that as top frequency band, created by a short septum length, ends below the higher frequency band (TX).

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.

In an example embodiment, a waveguide device comprises: a first common waveguide; a polarizer section, the polarizer section including a conductive septum dividing the first common waveguide into a first divided waveguide portion and a second waveguide divided portion; a second waveguide coupled to the first divided waveguide portion of the polarizer section; a third waveguide coupled to the second divided waveguide portion of the polarizer section; and a dielectric insert. The dielectric insert includes a first dielectric portion partially filling the polarizer section. The conductive septum and the dielectric portion convert a signal between a polarized state in the first common waveguide and a first polarization component in the second waveguide and a second polarization component in the third waveguide.