Base station antennas, and components for base station antennas, such as reflectors, feeder components, frames, and column components. A base station antenna may include a reflector; a first radiator located at the front side of the reflector; mutually parallel first and second ground plates extending backward from the reflector and basically perpendicular to the reflector; and a first conductor strip extending between the first and second ground plates and configured to feed power to the first radiator. The first conductor strip and the first and second ground plates may be configured as a first stripline transmission line. The reflector and the first and second ground plates may be configured as one piece so that the reflector is grounded via the first and second ground plates without soldering.

Base station antennas, and components for base station antennas, such as reflectors, feeder components, frames, and column components. A base station antenna may include a reflector; a first radiator located at the front side of the reflector; mutually parallel first and second ground plates extending backward from the reflector and basically perpendicular to the reflector; and a first conductor strip extending between the first and second ground plates and configured to feed power to the first radiator. The first conductor strip and the first and second ground plates may be configured as a first stripline transmission line. The reflector and the first and second ground plates may be configured as one piece so that the reflector is grounded via the first and second ground plates without soldering.

Surface elements, such as protrusions, are provided for use on the surface of flow-following apparatuses, such as surface drifters or subsurface drogues, to enhance the hydrodynamic properties of the apparatus and enhance their capabilities to follow fluid motion. The protrusions may comprise helical strakes or splitter plates for optimizing the drag-to-inertia ratio of the flow-following apparatus, with the goal to enhance their flow-following capabilities. In some embodiments, the flow-following apparatus has a generally axisymmetric body shape, such as having a cylindrical, spherical or oblong shape. The flow-following apparatus may further comprise a position tracking device to track flow motion such as ocean currents.

Surface elements, such as protrusions, are provided for use on the surface of flow-following apparatuses, such as surface drifters or subsurface drogues, to enhance the hydrodynamic properties of the apparatus and enhance their capabilities to follow fluid motion. The protrusions may comprise helical strakes or splitter plates for optimizing the drag-to-inertia ratio of the flow-following apparatus, with the goal to enhance their flow-following capabilities. In some embodiments, the flow-following apparatus has a generally axisymmetric body shape, such as having a cylindrical, spherical or oblong shape. The flow-following apparatus may further comprise a position tracking device to track flow motion such as ocean currents.

In one embodiment of the present disclosure, an antenna assembly includes a patch antenna array including an upper patch antenna layer, a lower patch antenna layer, and a spacer therebetween, wherein the spacer includes a plurality of apertures defined by cell walls, wherein the each aperture aligns with an upper patch antenna element and a lower patent antenna element from the patch antenna array.

An apparatus for reducing electromagnetic scattering includes a first component having a plurality of curved segments, each including a first reflective material, and together forming an enclosed cavity; and a second component having a plurality of flat or cylindrically-curved segments, each comprising a second reflective material. The second component is positioned external to the cavity.

An apparatus for reducing electromagnetic scattering includes a first component having a plurality of curved segments, each including a first reflective material, and together forming an enclosed cavity; and a second component having a plurality of flat or cylindrically-curved segments, each comprising a second reflective material. The second component is positioned external to the cavity.

A reflective antenna apparatus according to an exemplary embodiment of the present invention includes a feeder which receives an electromagnetic wave from a transmitter and distributes the electromagnetic wave to the antenna apparatus; a sub reflector which has a step formed to generate an orbital angular momentum (OAM) mode electromagnetic wave; and a main reflector which has a step formed to generate the same electromagnetic wave as the OAM mode generated by the sub reflector and cancels the OAM mode electromagnetic wave generated by the sub reflector and an OAM mode electromagnetic wave generated by the main reflector to radiate the electromagnetic waves to a far field.

A method for deploying an electromagnetic wave guiding structure includes a communication dead zone analysis step and an improvement measure determination step. In the former step, a frequency band in use and an electromagnetic wave signal strength threshold value are preset, and a processing module creates an electromagnetic map for the electromagnetic wave intensity over an area in the frequency band in use based on an electronic map of the area, wherein the electromagnetic map shows a communication dead zone. In the latter step, the processing module obtains an existing electromagnetic wave path according to the electromagnetic map and infers from the existing electromagnetic wave path the installation position and type of at least one electromagnetic wave guiding structure assembly suitable for use to guide the electromagnetic wave to the communication dead zone and ensure that the coverage ratio of the electromagnetic wave in the area reaches a threshold value.

A method for deploying an electromagnetic wave guiding structure includes a communication dead zone analysis step and an improvement measure determination step. In the former step, a frequency band in use and an electromagnetic wave signal strength threshold value are preset, and a processing module creates an electromagnetic map for the electromagnetic wave intensity over an area in the frequency band in use based on an electronic map of the area, wherein the electromagnetic map shows a communication dead zone. In the latter step, the processing module obtains an existing electromagnetic wave path according to the electromagnetic map and infers from the existing electromagnetic wave path the installation position and type of at least one electromagnetic wave guiding structure assembly suitable for use to guide the electromagnetic wave to the communication dead zone and ensure that the coverage ratio of the electromagnetic wave in the area reaches a threshold value.