A vehicle communication system includes a controller configured to be communicatively coupled to one or more antennas. The controller is also configured to adjust a beam during a period of time to be oriented at a plurality of pointing angles, and detect a plurality of sets of signal data for a received signal, where each set of signal data is detected at a different one of the pointing angles. The controller is further configured to identify a particular pointing angle based on the plurality of sets of signal data, reorient another beam from the given pointing angle to the particular pointing angle, and transmit or receive data, via the other beam while the other beam is oriented at the particular pointing angle, between a particular external node and at least one internal node.

In one example, an antenna system is described. The antenna system includes a primary antenna on an aircraft. The primary antenna is mechanically steerable and has an asymmetric antenna beam pattern with a narrow beamwidth axis and a wide beamwidth axis at boresight. The antenna system also includes a secondary antenna on the aircraft, the secondary antenna including an array of antenna elements. The antenna system also includes an antenna selection system to control communication of a signal between the aircraft and a target satellite via the primary antenna and the secondary antenna. The antenna selection system switches communication of the signal from the primary antenna to the secondary antenna when a performance characteristic for communication with the target satellite satisfies a threshold due to a position of the aircraft relative to the target satellite.

In one example, an antenna system is described. The antenna system includes a primary antenna on an aircraft. The primary antenna is mechanically steerable and has an asymmetric antenna beam pattern with a narrow beamwidth axis and a wide beamwidth axis at boresight. The antenna system also includes a secondary antenna on the aircraft, the secondary antenna including an array of antenna elements. The antenna system also includes an antenna selection system to control communication of a signal between the aircraft and a target satellite via the primary antenna and the secondary antenna. The antenna selection system switches communication of the signal from the primary antenna to the secondary antenna when a performance characteristic for communication with the target satellite satisfies a threshold due to a position of the aircraft relative to the target satellite.

An example apparatus includes a planar five bar linkage having a ground link and an endpoint. A feed horn is attached at or near the endpoint of the planar five bar linkage. A first motor is attached to a first side of the ground link to move the endpoint and a second motor attached to the second side of the ground link to move the endpoint.

The described features generally relate to adjusting a native antenna pattern of a satellite to adapt communications via the satellite. For example, a communications satellite may include an antenna having a feed array assembly, a reflector, and a linear actuator coupled between the feed array assembly and the reflector. The feed array assembly may have a plurality of feeds for communicating signals associated with a communications service, and the reflector may be configured to reflect the signals transmitted between the feed array assembly and one or more target devices. The linear actuator may have an adjustable length, or otherwise provide an adjustable position between the feed array assembly and the reflector. By adjusting the position of the feed array assembly relative to the reflector, the communications satellite may provide a communications service according to a plurality of native antenna patterns.

A radiofrequency antenna is adapted to be mounted on a spacecraft. The radiofrequency antenna includes four helical strands of a super elastic shape memory alloy and is configured to move from a deployed configuration to a constrained stacking configuration and to return autonomously to the deployed configuration.

A disclosed airborne vehicle includes split-ring resonators (split ring resonators), which may be embedded within a material. Each split ring resonator may be formed from a three-dimensional (3D) monolithic carbonaceous growth and may detect an electromagnetic ping emitted from a user device. Each split ring resonator may generate an electromagnetic return signal in response to the electromagnetic ping. The electromagnetic return signal may indicate a state of the material in a position proximate to a respective split ring resonator. In some aspects, each may resonate at a first frequency in response to the electromagnetic ping when the material is in a first state, and may resonate at a second frequency in response to the electromagnetic ping when the material is in a second state. A resonant frequency of the 3D monolithic carbonaceous growth may be based on physical characteristics of the material.

A test article described herein enables ground-based arc jet testing to investigate RF blackout mitigation using electrophilic gas injection upstream of an antenna. The article can be scaled up to actual flight vehicles, thereby allowing reentry vehicles to be in constant, or near constant, communication during atmospheric reentry. Plasma blackout mitigation is an enabling technology that is required to advance hypersonic flight. Example articles include an integral structure that supports a nozzle, piping for gas connected to the nozzle and an RF window. An ablator can be attached to the structure. The ablator can include a graphite ablator and an insulator. A flight vehicle can include an antenna and such an article.

A test article described herein enables ground-based arc jet testing to investigate RF blackout mitigation using electrophilic gas injection upstream of an antenna. The article can be scaled up to actual flight vehicles, thereby allowing reentry vehicles to be in constant, or near constant, communication during atmospheric reentry. Plasma blackout mitigation is an enabling technology that is required to advance hypersonic flight. Example articles include an integral structure that supports a nozzle, piping for gas connected to the nozzle and an RF window. An ablator can be attached to the structure. The ablator can include a graphite ablator and an insulator. A flight vehicle can include an antenna and such an article.

The present application relates to an electromagnetic band-gap, a directional antenna including same, and a use thereof. The electromagnetic band-gap structure and the directional antenna including same, of the present application, are lightweight and small in size, and can have excellent directivity. In addition, the electromagnetic band-gap structure and the directional antenna including same can be used for aviation electronic equipment and portable measurement equipment.