An antenna structure includes a radiator element configured for operation at a first microwave frequency range and at a second microwave frequency range that is higher than the first microwave frequency range, and a reflector including the radiator element attached thereto. The reflector includes an enclosure that houses the radiator element and a radiating aperture. The antenna structure further includes a radome assembly adjacent the radiating aperture. The radome assembly includes a flexible radome having a thickness that is less than a wavelength corresponding to the first or second microwave frequency ranges, and a tensioning member that extends along a perimeter of the flexible radome and maintains tension in a surface of the flexible radome.

A multi-core dielectric circular waveguide (MCDCW) is described. A hybrid mode excitation for multi-core dielectric filled circular waveguide fed parabolic antenna is also described. A multi-core dielectric circular waveguide with four cylinders of different relative permittivity (∈.sub.r) inside each other is used to generate the hybrid mode (HE.sub.11) directly without need for coupling TE.sub.11 and TM.sub.11 modes as in prior art corrugated waveguide feeders. This mode is preferable to be used as operating mode to feed the reflector. Four concentric cylinders of different relative permittivity ∈.sub.r are used as an example.

This application discloses an antenna, including a first antenna and a second antenna. The first antenna includes a first radiating element and a reflector. The reflector is located between the second antenna and the first radiating element. The reflector includes a connection part and a tooth part. The tooth part includes a plurality of comb teeth that are disposed side by side and that extend from the connection part toward the first radiating element. A gap is disposed between adjacent ones of the plurality of comb teeth. The tooth part further includes a profile facing the first radiating element. Each comb tooth includes an end part facing the first radiating element. The profile includes a concave part that is concave to the connection part.

An active passive antenna arrangement as made up of an array of 5G antennas interleaved with multiband antenna structures that may be low band (LB) passive antennas. The 5G antenna array may be a mMIMO active array. The LB antennas are formed using conductive elements on thin supporting sheets that fit within the space between the 5G antennas. The substrates, and hence the radiating elements of the LB antennas, may be arranged so as to generally appear to form four sides of a rectangular box with the top and bottom surfaces removed. Thus, the LB antennas may be thought of as having been “slipped in” amongst a preexisting array of 5G antennas. Each LB antenna may surround one or more of the 5G antennas and 5G antennas of the array may also be external to an LB antenna.

A beam reconstruction method includes: generating or receiving a radio frequency signal, determining a to-be-adjusted beam angle, loading a voltage bias value on each liquid crystal metasurface array unit among a plurality of liquid crystal metasurface array units in a liquid crystal metasurface array based on the beam angle, and either emitting the generated radio frequency signal transmitted through the liquid crystal metasurface array or directing the received radio frequency signal through the liquid crystal metasurface array to a feed of an antenna. A lateral offset of a feed phase center is generated based on the voltage bias value after the radio frequency signal is transmitted through the liquid crystal metasurface array.

A beam reconstruction method includes: generating or receiving a radio frequency signal, determining a to-be-adjusted beam angle, loading a voltage bias value on each liquid crystal metasurface array unit among a plurality of liquid crystal metasurface array units in a liquid crystal metasurface array based on the beam angle, and either emitting the generated radio frequency signal transmitted through the liquid crystal metasurface array or directing the received radio frequency signal through the liquid crystal metasurface array to a feed of an antenna. A lateral offset of a feed phase center is generated based on the voltage bias value after the radio frequency signal is transmitted through the liquid crystal metasurface array.

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.

An orthomode transducer and to a satellite transmission chain includes the orthomode transducer, for transmitting a first signal and a second signal in orthogonal propagation modes. The transducer comprises: a primary waveguide with a square or rectangular cross section, two guided access means having firstly a free end via which the first signal and the second signal are respectively injected or recovered, and secondly two arms connected to the primary waveguide. Each guided access means comprises a junction configured so as to connect the free end to the two arms of the guided access means, the two arms of each guided access means being connected to the primary waveguide at two off-centred locations on one or more sides of the primary waveguide symmetrically about an axis of symmetry of the primary waveguide.

An orthomode transducer and to a satellite transmission chain includes the orthomode transducer, for transmitting a first signal and a second signal in orthogonal propagation modes. The transducer comprises: a primary waveguide with a square or rectangular cross section, two guided access means having firstly a free end via which the first signal and the second signal are respectively injected or recovered, and secondly two arms connected to the primary waveguide. Each guided access means comprises a junction configured so as to connect the free end to the two arms of the guided access means, the two arms of each guided access means being connected to the primary waveguide at two off-centred locations on one or more sides of the primary waveguide symmetrically about an axis of symmetry of the primary waveguide.

An antenna system steerable in any direction and methods of use are provided. In an embodiment, the antenna system comprises a substantially ellipsoid-shaped shell body and a plurality of cells coupled to the body, wherein each cell comprises a conductive material. In an embodiment, the shell body comprises a metasurface. In an embodiment, the antenna system further includes a plurality of switches coupled to the plurality of cells, wherein each switch is configured to change its coupled cell between reflective, transmissive, and absorptive states. The antenna system further includes a feed radiator located at or around the center of the shell body; a radio coupled to the feed; and a processor coupled to the feed, radio, and the plurality of switches, wherein the processor is configured to produce a shaped beam by controlling a subset of the plurality of switches.