Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.

Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.

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.

Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.

Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.

A radio frequency waveguide is disclosed. The radio frequency waveguide includes: a dielectric including an exterior input surface, an exterior output surface and other exterior surfaces; and a metal disposed on the other exterior surfaces of the dielectric, wherein the dielectric is voidless and adapted to propagate radio frequency radiation from the exterior input surface to the exterior output surface.

In one example an apparatus is provided. The apparatus includes a low frequency radiator, a high frequency radiator, a high frequency waveguide that carries high frequency bands to the high frequency radiator, a low frequency coaxial waveguide coupled to the high frequency waveguide in a coaxial structure, wherein the low frequency coaxial waveguide carries low frequency bands to the low frequency radiator and a low frequency combiner in communication with the low frequency coaxial waveguide, wherein the low frequency combiner comprises a circular low frequency waveguide and air dielectric transmission lines formed by air channels formed above and below a plurality of printed circuits in a metal housing.

Photodiode structures and methods of manufacture are disclosed. The method includes forming a waveguide structure in a dielectric layer. The method further includes forming a Ge material in proximity to the waveguide structure in a back end of the line (BEOL) metal layer. The method further includes crystallizing the Ge material into a crystalline Ge structure by a low temperature annealing process with a metal layer in contact with the Ge material.

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 feed assembly for that operates at different frequency bands (e.g., low, mid and high frequency bands) is provided herein. The feed assembly includes a feed horn common to low, mid and high frequency bands, a coaxial polarizer to launch signals in the low band frequency band, a coaxial orthomode transducer (OMT) to launch signals in the low band frequency band and supports the mid and high frequency bands, and a polyrod disposed in a center conductor of the feed assembly, the polyrod common to the mid and high frequency bands. The feed assembly includes a tri-band feed assembly having different portions to support signals in the low frequency band and signals in the mid and high frequency bands.