An aerial deployed radio antenna system includes a primary aerial vehicle and a plurality of secondary aerial vehicles coupled to the primary aerial vehicle with a primary tether, wherein the plurality of secondary aerial vehicles are coupled to each other with a plurality of secondary tethers. The system also includes a radar-reflective sheet suspended between and supported by a plurality of cables coupled to the plurality of secondary aerial vehicles, wherein the radar-reflective sheet forms a parabolic reflector shape when deployed and towed by the primary aerial vehicle. A radar transmitter/receiver is positioned relative to the radar-reflective sheet to transmit radar signals toward the radar-reflective sheet and receive radar signals focused by the radar-reflective sheet, and a plurality of solar cells is positioned on the radar-reflective sheet. The plurality of solar cells are electrically coupled to a power collector configured to supply solar-generated electrical power to the radar transmitter/receiver.

The invention is directed to an antenna structure for producing a horizontally polarized beam. In one embodiment, the antenna structure includes a first quarter-wave patch antenna and a second quarter-wave patch antenna that are positioned such that the ground planes of the patch antennas or a ground plane shared by the patch antennas is disposed between the patches of the two antennas and the shorting structures associated with the antennas are substantially aligned. In operation, the antenna structure is capable of processing an omni-directional, horizontally polarized beam.

A system for subsurface transmission includes an array of very low frequency (VLF) transmitter nodes supported by semi-autonomous maritime, airborne, or space platforms spaced at regular intervals from their nearest neighbors and phased to localize VLF coverage to some desired area on a body of water.

A system for subsurface transmission includes an array of very low frequency (VLF) transmitter nodes supported by semi-autonomous maritime, airborne, or space platforms spaced at regular intervals from their nearest neighbors and phased to localize VLF coverage to some desired area on a body of water.

An aerial deployed radio antenna system includes a primary aerial vehicle and a plurality of secondary aerial vehicles coupled to the primary aerial vehicle with a primary tether, wherein the plurality of secondary aerial vehicles are coupled to each other with a plurality of secondary tethers. The system also includes a radar-reflective sheet suspended between and supported by a plurality of cables coupled to the plurality of secondary aerial vehicles, wherein the radar-reflective sheet forms a parabolic reflector shape when deployed and towed by the primary aerial vehicle. A radar transmitter/receiver is positioned relative to the radar-reflective sheet to transmit radar signals toward the radar-reflective sheet and receive radar signals focused by the radar-reflective sheet, and a plurality of solar cells is positioned on the radar-reflective sheet. The plurality of solar cells are electrically coupled to a power collector configured to supply solar-generated electrical power to the radar transmitter/receiver.

An aerial deployed radio antenna system includes a primary aerial vehicle and a plurality of secondary aerial vehicles coupled to the primary aerial vehicle with a primary tether, wherein the plurality of secondary aerial vehicles are coupled to each other with a plurality of secondary tethers. The system also includes a radar-reflective sheet suspended between and supported by a plurality of cables coupled to the plurality of secondary aerial vehicles, wherein the radar-reflective sheet forms a parabolic reflector shape when deployed and towed by the primary aerial vehicle. A radar transmitter/receiver is positioned relative to the radar-reflective sheet to transmit radar signals toward the radar-reflective sheet and receive radar signals focused by the radar-reflective sheet, and a plurality of solar cells is positioned on the radar-reflective sheet. The plurality of solar cells are electrically coupled to a power collector configured to supply solar-generated electrical power to the radar transmitter/receiver.

A multi-layer antenna for near-field communications can have a first layer on a top surface of flexible circuit board and a second layer on a bottom surface of the flexible circuit board. The first layer and the second layer can be connected in series by a through connection in the flexible circuit board. The first layer can incorporate a single loop in the shape of a rectangle and the second layer can incorporate a single loop in the shape of a rectangle. The second layer of the antenna can be vertically aligned with the first layer of the antenna and can have current flow in the same direction as the first layer to provide for an increased magnetic flux from the antenna.

An unmanned aerial vehicle (UAV) includes an antenna assembly configured to communicate with a ground terminal controller, a memory storing antenna assembly configuration information, and one or more processors configured to adjust a radiation direction pattern of the antenna assembly according to the antenna assembly configuration information.

A spar buoy for very low frequency (VLF) or low frequency (LF) transmission including a first portion of the spar buoy extending above a mean water line including a conductive structure including a coaxial feed, and an antenna coupled to the coaxial feed and extending above the conductive structure, and a second portion of the spar buoy below the mean water line including a transmitter coupled to the coaxial feed, an energy storage subsystem coupled to the transmitter and an electric power generation subsystem coupled to the energy storage subsystem.

A spar buoy for very low frequency (VLF) or low frequency (LF) transmission including a first portion of the spar buoy extending above a mean water line including a conductive structure including a coaxial feed, and an antenna coupled to the coaxial feed and extending above the conductive structure, and a second portion of the spar buoy below the mean water line including a transmitter coupled to the coaxial feed, an energy storage subsystem coupled to the transmitter and an electric power generation subsystem coupled to the energy storage subsystem.