A dual-band antenna for global positioning system includes a plurality of dipole antenna arranged to operate in a L1 band and a L2 band; a back cavity structure mounted to the plurality of dipole antennas, wherein the plurality of dipole antennas are at least partially accommodated within a back cavity defined by the back cavity structure; and a feed network provided on the back cavity structure and coupled to the plurality of dipole antennas.

Shroud isolation, including choke shroud isolation, apparatuses for wireless antennas for point-to-point or point-to-multipoint transmission/communication of high bandwidth signals, and integrated reflectors including a shroud or choke shroud. A choke shroud systems may include a cylindrical body with an isolation choke boundary at the distal opening to attenuate electromagnetic signals to, from, or within the antenna. The isolation choke boundary region may have ridges that may be tuned to a band of interest. The isolation choke boundary may provide RF isolation when used near other antennas.

A measurement system is provided. The measurement system comprises a device under test, at least two measurement antennas, and a reflector. In this context, the reflector comprises at least two separate curved surfaces in the same physical entity in order to generate separate plane waves corresponding to the at least two measurement antennas. The reflector is configured in such a manner that the separate plane waves converge in a quiet-zone comprising the device under test.

An antenna assembly includes an array of patch antennas arranged above a rectangular ground plane. The patch antennas are arranged in a sequence beginning at a first end of the rectangular ground plane and continuing across a width of the rectangular ground plane to a second end. With regard to this sequence, a plurality of polarization feeds alternate between being adjacent a first corner to being adjacent a second corner of the patch antennas and/or a plurality of via walls alternate in orientation along portions of a first edge of the rectangular ground plane and along portions of a second edge of the rectangular ground plane.

A reflector for deflecting electromagnetic waves is provided. Said reflector comprises a resistive material along its edges in a specific pattern, wherein the resistive material has a resistance per square meter being higher than the resistance per square meter of the material of the reflector in order to attenuate and/or absorb electromagnetic energy of the electromagnetic waves.

A reflector for deflecting electromagnetic waves is provided. Said reflector comprises a resistive material along its edges in a specific pattern, wherein the resistive material has a resistance per square meter being higher than the resistance per square meter of the material of the reflector in order to attenuate and/or absorb electromagnetic energy of the electromagnetic waves.

A measurement system is provided. The measurement system comprises a device under test, at least two measurement antennas, and a reflector. In this context, the reflector comprises at least two separate curved surfaces in the same physical entity in order to generate separate plane waves corresponding to the at least two measurement antennas. The reflector is configured in such a manner that the separate plane waves converge in a quiet-zone comprising the device under test.

An antenna assembly includes an array of patch antennas arranged above a rectangular ground plane. The patch antennas are arranged in a sequence beginning at a first end of the rectangular ground plane and continuing across a width of the rectangular ground plane to a second end. With regard to this sequence, a plurality of polarization feeds alternate between being adjacent a first corner to being adjacent a second corner of the patch antennas and/or a plurality of via walls alternate in orientation along portions of a first edge of the rectangular ground plane and along portions of a second edge of the rectangular ground plane.

An antenna that radiates non-dispersive and time-aligned wave-fronts at all angles of radiation (in a half space). The antenna consists of a source radiator enclosed within a metallic shield with an aperture opening to couple plane waves radiated by the source through the aperture. Pulse dispersion is eliminated by having a truly planar aperture, resulting in an abrupt radiation zone, and the aperture field distribution being uniform. Wave-front alignment is caused by the continuity of the coupled electric field lines of force onto the metallic shield to result in radiated spherical waves. The antenna transfer function is impulse-like for all angles of radiation, thus it can be considered a distortion-less antenna.

An apparatus and related method are disclosed for compensation of an antenna and/or an antenna array located at a surface that experiences environmental conditions. The apparatus can include: an embedded compensation and/or calibration structure configured to be interrogated by an electromagnetic wave, to dynamically compensate for surface erosion, thermal expansion, and/or dielectric constant changes of a surface scattering antenna; and a processor configured to: receive measurements of the compensation and/or calibration structure to determine beam pointing for dynamically varying surface conditions and perform sensing and/or seeking observation.