An apparatus for space and terrestrial communication applications includes a Ka-band horn combined with a S-band cross-polarization cup. The S-band cross-polarization cup is placed around a neck of the Ka-band horn in a form of a collar.

Systems and methods for designing, optimizing, patterning, forming, and manufacturing symphotic structures are described herein. A symphotic structure may be formed by identifying a continuous refractive index distribution calculated to convert each of a plurality of input reference waves to a corresponding plurality of output object waves. The continuous refractive index distribution can be modeled as a plurality of subwavelength voxels. The system can calculate a symphotic pattern as a three-dimensional array of discrete dipole values to functionally approximate the subwavelength voxels. A symphotic structure may be formed with a volumetric distribution of dipole structures. A dipole value, such as a dipole moment (direction and magnitude) of each dipole is selected for the volumetric distribution to convert a plurality of input reference waves to a target plurality of output object waves.

In an antenna module on one printed circuit board, a first area where a plurality of antenna elements are positioned on a first surface, and a second area where a plurality of front end integrated circuits are independently positioned on a second surface, the opposite surface of the first surface, are provided, and a wire is provided in the second area to electrically couple some ports of a plurality of ports provided in a first front end integrated circuit to some ports of a plurality of ports provided in a second front end integrated circuit. The some ports provided in the first front end integrated circuit include a first port configured to output a first intermediate frequency signal, and a second port configured to input a second intermediate frequency signal.

A distributed antenna system comprises: one or more access units configured to receive multiple downlink radio frequency signal sets, and further configured to convert the multiple downlink radio frequency signal sets into multiple downlink optical signal sets; a first wavelength division multiplexing unit configured to multiplex the multiple downlink optical signal sets to generate a first wavelength division multiplexing optical signals; a first wavelength division demultiplexing unit configured to demultiplex the first wavelength division multiplexing optical signals to obtain the multiple downlink optical signal sets; a first optical fiber, coupled between the first wavelength division multiplexing unit and the first wavelength division demultiplexing unit, and configured to transmit the first wavelength division multiplexing optical signal; and multiple first remote units coupled to the first wavelength division multiplexing unit, and configured to convert the multiple downlink optical signal sets into the multiple downlink radio frequency signal sets for transmission.

Receiving antenna (1) for terahertz radiation (30), comprising an antenna conductor (2) and a first photoconductor (3) connected to the antenna conductor (2) and activatable by light (9), the first photoconductor (3) allowing, in an activated state, an antenna current (28) flowing through the antenna conductor (2) and the first photoconductor (3), characterized in that the receiving antenna (1) comprises at least one second photoconductor (4) connected to the antenna conductor (2) and activatable by light (9), the second photoconductor connected in parallel with the first photoconductor (3) and, in an activated state, allowing an antenna current (28) flowing through the antenna conductor (2) and the second photoconductor (4), wherein at least one respective high-pass filter (8) is connected between each of the photoconductors (3, 4) and the antenna conductor (2). The invention further relates to a receiver for terahertz radiation (30), a terahertz system, and a method for generating and detecting terahertz radiation (30) using such a terahertz system.

A unit cell can be used for a metasurface, metamaterial, or beamforming antenna. The unit cell includes a metal layer attached to a substrate. The metal layer defines an iris opening for the unit cell. One or more tunable capacitance devices are positioned within or across the iris opening. Each tunable capacitance device is to tune resonance frequency of the unit cell. Mass transfer technologies or self-assembly processes may be used to position the tunable capacitance devices.

A unit cell can be used for a metasurface, metamaterial, or beamforming antenna. The unit cell includes a metal layer attached to a substrate. The metal layer defines an iris opening for the unit cell. One or more tunable capacitance devices are positioned within or across the iris opening. Each tunable capacitance device is to tune resonance frequency of the unit cell. Mass transfer technologies or self-assembly processes may be used to position the tunable capacitance devices.

A dual polarized antenna feed system can include a first single polarized antenna feed element oriented on a first axis relative to a polarization filter and a second single polarized antenna feed element oriented on a second axis relative to the polarization filter such that the first and second axes are not common and not parallel. The polarization filter can include a plurality of conductors, a polarization of the first single polarized antenna feed element can be parallel to the plurality of conductors so that the polarization filter can reflect a majority of incident signals originating from the first single polarized antenna feed element, and a polarization of the second single polarized antenna feed element can be orthogonal to the plurality of conductors so that the polarization filter can be transparent to a majority of incident signals originating from the second single polarized antenna feed element.

An array antenna capable of steering a beam in a first communication node of a wireless communication system may comprise: a plurality of single antennas each capable of variably adjusting a beam steering direction; a plurality of beamforming control units each of which is connected to each of the plurality of single antennas to control a beamforming operation of each of the plurality of single antennas; and an array antenna control unit connected to the plurality of beamforming control units to control a beamforming operation of the entire array antenna, wherein the plurality of single antennas are arranged in a cylindrical shape and are installed to face a direction opposite to a central direction of the cylinder shape, and the array antenna is configured to steer a beam to a predetermined area around the first communication node through at least one single antenna among the plurality of single antennas.

An MIMO training method including performing transmission sector sweeping using an initiator including a plurality of transmitting antennas, selecting a set of at least one transmission sector for each of the transmitting antennas using a responder including a plurality of receiving antennas; performing reception sector sweeping using the initiator, selecting a set of at least one reception sector for each of the plurality of receiving antennas using the responder, performing beam combination training using the initiator; and selecting a determined number of sector pairs consisting of a transmission sector and a reception sector from among the selected set of transmission sectors and the selected set of reception sectors using the responder, wherein the transmitting antennas in the selected sector pairs differ from one another, and the receiving antennas in the selected sector pairs differ from one another.