A nonplanar metamaterial polarizer includes: a substrate including dielectric material transmissive to electromagnetic radiation and having a nonplanar shape; a first conductive pattern on a first side of the substrate; and a second conductive pattern on a second side of the substrate. The first and second conductive patterns are configured to alter the polarization of the electromagnetic radiation as it transmits through the substrate. In some cases, the first and second conductive patterns include split-ring resonators, and the nonplanar shape is a cylinder. An antenna system includes the nonplanar metamaterial polarizer and an antenna inside or adjacent to the nonplanar metamaterial polarizer and configured to transmit or receive the electromagnetic radiation through the nonplanar metamaterial polarizer while the nonplanar metamaterial polarizer alters the polarization of the transmitted or received electromagnetic radiation. In some cases, the antenna is a monopole antenna, a dipole antenna, a biconical antenna, or a discone antenna.

An ultra-wideband linear-to-circular polarizer is disclosed. In accordance with embodiments of the invention, the polarizer includes a plurality of cascaded waveplates having biaxial permittivity or cascaded anisotropic sheet impedances. Each waveplate/sheet has a principal axis rotated at different angles relative to an adjacent waveplate/sheet about a z-axis of a 3-dimensional x, y, z coordinate system. Each waveplate is composed of a unit cell of an artificial anisotropic dielectric. Each sheet impedance is composed of an anisotropic metallic pattern. The polarizer further includes impedance matching layers disposed adjacent the cascaded waveplates/sheets.

According to one embodiment, an antenna apparatus includes a first phase shifter to shift a phase of a left-hand circularly polarized signal representing a left-hand circularly polarized wave; a second phase shifter to shift a phase of a right-hand circularly polarized signal representing a right-hand circularly polarized wave; a control circuit determining a first phase shift amount of the first phase shifter and a second phase shift amount of the second phase shifter based on a difference between a phase shift amount of the first phase shifter and a phase shift amount of the second phase shifter; and a radiating element radiating the left-hand circularly polarized wave and the right-hand circularly polarized wave based on the left-hand circularly polarized signal of which the phase is shifted by the first phase shift amount and the right-hand circularly polarized signal of which the phase is shifted by the second phase shift amount.

Microwave antenna systems include a parabolic reflector antenna and a dual-band feed assembly. The dual-band feed assembly includes a coaxial waveguide structure and a sub-reflector. The coaxial waveguide structure includes a central waveguide and an outer waveguide that circumferentially surrounds the central waveguide. The sub-reflector is mounted proximate the distal end of the coaxial waveguide structure.

The present disclosure relates to a satellite signal feeding module and circuit board structure. The circuit board includes a dielectric substrate, a plurality of grounding sheets, a plurality of top feed sheets, a plurality of bottom feed sheets, and a conductive layer. The dielectric substrate includes a main segment having an opening, a rib segment extending across a full width of the opening, and a plurality of extending segments connected to the main segment. The grounding sheets cover the rib segment and a majority portion of the main segment. The top feeding sheets and the bottom sheets cover the extending segments. The conductive layer is disposed in first holes disposed in the main segment and the rib segment for electrically coupling the grounding sheets. The conductive layer is further disposed in second holes in the extending segments for electrically coupling the top and bottom feeding sheets.

Disclosed is an antenna device including a rectangular waveguide (1) having a first opening end (2a) and a second opening end (2b), a septum phase plate (3) disposed inside the rectangular waveguide (1) in such a way as to partition the first opening end (2a) into two parts along a first direction perpendicular to a waveguide axial direction of the rectangular waveguide (1), a width of the septum phase plate in a second direction perpendicular to both the waveguide axial direction of the rectangular waveguide (1) and the first direction becoming narrower stepwise with advancing from the first opening end (2a.sub.1, 2a.sub.2) toward the second opening end (2b), and first projecting portions (4a, 4b) disposed on two respective first inner walls (1a, 1b) parallel to the septum phase plate (3), out of four inner walls of the rectangular waveguide (1), in such a way as to project toward an inside of the rectangular waveguide (1).

An ultra-wideband linear-to-circular polarizer is disclosed. In accordance with embodiments of the invention, the polarizer includes a plurality of cascaded waveplates having biaxial permittivity or cascaded anisotropic sheet impedances. Each waveplate/sheet has a principal axis rotated at different angles relative to an adjacent waveplate/sheet about a z-axis of a 3-dimensional x, y, z coordinate system. Each waveplate is composed of a unit cell of an artificial anisotropic dielectric. Each sheet impedance is composed of an anisotropic metallic pattern. The polarizer further includes impedance matching layers disposed adjacent the cascaded waveplates/sheets.

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.

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.

A three-dimensional resonant chamber is described. The three-dimensional resonant chamber may support a plurality of circularly polarized modes at a desired frequency. The desired frequency may be in an ISM (Industrial, Scientific, Medical) frequency band, such as in the 902 MHz-928 MHz or in the 2.4 GHz-2.5 GHz. The three-dimensional resonant chamber may include one or more openings for coupling electromagnetic radiation outside the three-dimensional resonant chamber. The three-dimensional resonant chamber may be disposed in a cavity, such as a microwave oven, and may be configured to excite the cavity through the one or more openings. The three-dimensional resonant chamber may be connected to a waveguide support a circularly polarized mode.