An adaptable microwave radio transceiver system having a microwave radio transceiver and at least two waveguide adapters, where the microwave radio transceiver is adapted for at least two waveguide frequency bands and includes at least one radio port that includes a corresponding probe of a fixed length and extends via an inner insulating part in a bottom in the corresponding radio port. Each waveguide adapter comprises has a first end facing the corresponding bottom where each first end includes a bottom wall with an outer insulating part through which the corresponding probe is adapted to protrude a protrusion distance. The protrusion distance is dependent on a thickness of the bottom wall, where at least two waveguide adapters have different thickness of the corresponding bottom wall, where any one of the waveguide adapters is exchangeably mountable to the radio port.

An adaptable microwave radio transceiver system having a microwave radio transceiver and at least two waveguide adapters, where the microwave radio transceiver is adapted for at least two waveguide frequency bands and includes at least one radio port that includes a corresponding probe of a fixed length and extends via an inner insulating part in a bottom in the corresponding radio port. Each waveguide adapter comprises has a first end facing the corresponding bottom where each first end includes a bottom wall with an outer insulating part through which the corresponding probe is adapted to protrude a protrusion distance. The protrusion distance is dependent on a thickness of the bottom wall, where at least two waveguide adapters have different thickness of the corresponding bottom wall, where any one of the waveguide adapters is exchangeably mountable to the radio port.

In one embodiment, an antenna assembly includes a reflector antenna whose aperture is covered by a radome. The radome has a principle plane corresponding to the azimuth axis of the antenna. The radome has a bulk material and a pair of absorbers made of a radio-frequency (RF)-absorbent material different from the bulk material. The pair of absorbers are arranged symmetrically along the principle plane and about the center of the radome. The pair of absorbers are located near the perimeter of the radome and are at least partially embedded in the bulk material. The pair of absorbers cover from 4%-8% of the total aperture area of the antenna.

In one embodiment, an antenna assembly includes a reflector antenna whose aperture is covered by a radome. The radome has a principle plane corresponding to the azimuth axis of the antenna. The radome has a bulk material and a pair of absorbers made of a radio-frequency (RF)-absorbent material different from the bulk material. The pair of absorbers are arranged symmetrically along the principle plane and about the center of the radome. The pair of absorbers are located near the perimeter of the radome and are at least partially embedded in the bulk material. The pair of absorbers cover from 4%-8% of the total aperture area of the antenna.

Disclosed is a shaped horn in conjunction with a dielectric tube for enhanced aperture directivity that can achieve a near optimum efficiency. The shaped horn provides additional mode control to provide an improved off-axis cross-polarization response. The horn shape can be individually optimized for isolated horns or for horns in a feed array. The feed array environment can produce results that lead to a different optimized shape than the isolated horn. Lower off axis cross-polarization can result in improved efficiency and susceptibility to interference.

Methods and systems are described for providing end-to-end beamforming. For example, end-to-end beamforming systems include end-to-end relays and ground networks to provide communications to user terminals located in user beam coverage areas. The ground segment can include geographically distributed access nodes and a central processing system. Return uplink signals, transmitted from the user terminals, have multipath induced by a plurality of receive/transmit signal paths in the end to end relay and are relayed to the ground network. The ground network, using beamformers, recovers user data streams transmitted by the user terminals from return downlink signals. The ground network, using beamformers generates forward uplink signals from appropriately weighted combinations of user data streams that, after relay by the end-end-end relay, produce forward downlink signals that combine to form user beams.

Microwave antennas having optimized performance are provided. The microwave antennas include a primary reflector having effective foci arranged in a generally circular or elliptic range around a central axis thereof, and a matching component filling a hole at a bottom center portion thereof. The structural parameters of the microwave antenna are tuned by an aperture field analysis method to optimize the overall performance.

In one embodiment, a sub-reflector assembly for a reflector antenna has (i) a waveguide transition at a waveguide end of the sub-reflector assembly and configured to fit within a waveguide, (ii) a dielectric radiator connected to the waveguide transition and extending both laterally and back towards the waveguide end of the sub-reflector assembly, and (iii) a sub-reflector connected to the dielectric radiator. By configuring the dielectric radiator to extend both laterally and back towards the dielectric end of the assembly, radiated energy from the waveguide is directed such that the sub-reflector assembly can be used with shallow reflector dishes (e.g., F/D ratio greater than 0.25) and still achieve sufficiently high directivity.

Example embodiments relate to low elevation side lobe antennas with fan-shaped beams. An example radar unit may include a radiating plate having a first side and a second side with an illuminator, a waveguide horn, a waveguide opening, and a radiating sleeve extending into the first side of the radiating plate. The waveguide opening is positioned on the first end of the first side and the radiating sleeve is positioned on the second end of the first side. The radar unit also includes a metallic cover coupled to the first side of the radiating plate such that the metallic cover and the radiating plate form waveguide structures. The waveguide horn is configured to receive, from an external source, electromagnetic energy provided through the waveguide opening via a first waveguide and provide a portion of the electromagnetic energy to the illuminator via a second waveguide such that the portion of the electromagnetic energy radiates off the illuminator and through the radiating sleeve into an environment of the radar unit as one or more radar signals.

An antenna array and a wireless communications device are disclosed. The antenna array includes at least two directional antennas in different directions. Each directional antenna includes an antenna element, a reflector, a feed line coupled to the antenna element, and a switch for controlling the feed line. The antenna element is a microstrip dipole antenna element. The reflector is a parasitic microstrip antenna element. A length of the reflector is greater than a length the antenna element. Two ends of the reflector are bent toward the antenna element. A distance between midpoints of reflectors of any two directional antennas is less than a distance between midpoints of antenna elements thereof. Because the reflectors of the antenna array are located on an inner side of a pattern enclosed by the antenna elements of directional antennas, a size of the antenna array is small.