Microwave antenna systems include a parabolic reflector antenna having a feed bore and a feed assembly. The feed assembly includes a coaxial waveguide structure that extends through the feed bore, a sub-reflector, and a first dielectric block that is positioned between the coaxial waveguide structure and the sub-reflector. The coaxial waveguide structure includes a central waveguide and an outer waveguide that circumferentially surrounds the central waveguide. One of the central waveguide and the outer waveguide extends further from the feed bore towards the sub-reflector than the other of the central waveguide and the outer waveguide.

A reflector antenna device includes: a primary radiator to radiate a first radio wave in a first frequency band and a second radio wave in a second frequency band lower in frequency than the first frequency band; and a reflector having a reflection face reflecting the first radio wave and the second radio wave radiated by the primary radiator, in which the reflection face of the reflector has a first region including a center point of the reflection face and a second region that is an outer peripheral region of the first region and is provided with a plurality of recesses, and each of the plurality of recesses is configured to allow entrance of the first radio wave, restrict entrance of the second radio wave, and reflect the first radio wave having entered the recess on a bottom face of the recess.

A reflector antenna device includes: a primary radiator to radiate a first radio wave in a first frequency band and a second radio wave in a second frequency band lower in frequency than the first frequency band; and a reflector having a reflection face reflecting the first radio wave and the second radio wave radiated by the primary radiator, in which the reflection face of the reflector has a first region including a center point of the reflection face and a second region that is an outer peripheral region of the first region and is provided with a plurality of recesses, and each of the plurality of recesses is configured to allow entrance of the first radio wave, restrict entrance of the second radio wave, and reflect the first radio wave having entered the recess on a bottom face of the recess.

A portable antenna terminal includes a deck on which is mounted a storage frame, and on which there is also supported an antenna that includes a kingpost shaft and a modular reflector that is formed from a plurality of reflector panels and a central reflector hub. The storage frame defines a storage space for storing the plurality of reflector panels and a receptacle for secured reception of the reflector hub. When fully loaded with all terminal components, the terminal has a total weight of equal to or less than 10,000 lbs., preferably equal to or less than 7,500 lbs., and more preferably equal to or less than 5,000 lbs. In a storage configuration, with the modular antenna components secured in stored positions, the terminal has dimensions equal to or less than 84 in. L×104 in. W×92 in. H.

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.

The example non-limiting technology herein provides a Synthetic Aperture Radar (SAR) solution on board a micro-satellite that provides global revisit within 1 month; a cost below US$ 10 million; and satellite mass lower than 100 kg. One solution uses an inflatable Cassegrain type antenna with a phased beam steering array in the 1.2 GHz band.

A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.

A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.

Double reflector electromagnetic systems implementable in miniaturized satellites and other applications for compact, light weight, and broadband antennas. The disclosed methods and devices include primary and secondary reflectors, where the secondary reflector is held in the aperture plane of the primary reflector to minimize required space. A specific Cassegrain configuration is also described.

Double reflector electromagnetic systems implementable in miniaturized satellites and other applications for compact, light weight, and broadband antennas. The disclosed methods and devices include primary and secondary reflectors, where the secondary reflector is held in the aperture plane of the primary reflector to minimize required space. A specific Cassegrain configuration is also described.