Abstract: An antenna 300 comprising a housing 310 with an internal cavity 315. The cavity 315 holds an adjustable amount of electrically conductive liquid, and a twin-conductor feedline 350 connects the antenna 300 to a receiving and/or transmitting device. The conductive liquid in the cavity 315 of the antenna housing 310 acts as a first element and receives/transmits signals from/to the first feedline conductor, whilst the second feedline conductor is attached to electrical ground 320.

Abstract: In some examples, a biasing structure for a unit cell of a meta-surface comprises a first illumination source to irradiate a first photovoltaic element, the first photovoltaic element so configured as to generate a biasing current to bias an active asymmetrically conducting device bridging a pair of electrically separated conductive patches defining a surface of the unit cell.

Abstract: An antenna 300 comprising a housing 310 with an internal cavity 315. The cavity 315 holds an adjustable amount of electrically conductive liquid, and a twin-conductor feedline 350 connects the antenna 300 to a receiving and/or transmitting device. The conductive liquid in the cavity 315 of the antenna housing 310 acts as a first element and receives/transmits signals from/to the first feedline conductor, whilst the second feedline conductor is attached to electrical ground 320.

Abstract: A small, portable wireless router combined with a wideband, wearable antenna supports a local wireless network created on the move for exchanging information between multiple personnel spread over a useful geographic area. Multiple information sources of different types, such as cameras and GPS, can use the network to send information feeds to mobile users with interface devices such as smartphones that can deliver multiple feeds at the same time to the user. Devices connected to other networks, such as information processing devices at fixed operating bases, can deliver information feeds to the network.

Abstract: An antenna assembly is disclosed which includes a layered structure having a planar array of antenna elements; and a feed arrangement perpendicular to the antenna elements; the layered structure further having layers over the planar array of antenna elements with holes provided therethrough to allow the feed arrangement to be connected to contacts for the antenna elements. The layered structure may include vias provided such that heat may be applied remotely to the contacts.

Abstract: A spinal immobilization device is disclosed. The spinal immobilization device may include a plurality of cleats disposed on the bottom of the spinal immobilization device to prevent damage to the spinal immobilization device. The spinal immobilization device may include one or more pieces of reflective tape disposed on the perimeter of the transparent board frame to illuminate the spinal immobilization device and to protect the one or more caregiver users and the second user. The spinal immobilization device may accommodate one or more ambidextrous users, where either side of the spinal immobilization device may be utilized as a head side or a foot side. The spinal immobilization device may be made of transparent material and X-Ray translucent material to allow the one or more caregiver users to easily view the second user's injuries and allow X-raying the second user's injuries while the second user is secured in the spinal immobilization device.

Abstract: A small, portable wireless router combined with a wideband, wearable antenna supports a local wireless network created on the move for exchanging information between multiple personnel spread over a useful geographic area. Multiple information sources of different types, such as cameras and GPS, can use the network to send information feeds to mobile users with interface devices such as smartphones that can deliver multiple feeds at the same time to the user. Devices connected to other networks, such as information processing devices at fixed operating bases, can deliver information feeds to the network.

Abstract: A dipole array assembly, is disclosed which includes a plurality of poles arranged in a two-dimensional array to provide a plurality of dipoles, each pole being shaped such that adjacent edges of neighbouring poles that are from respective neighbouring dipoles are relatively long and relatively close to each other compared to the dimensions of the poles, thereby increasing coupling between different dipoles. A feed arrangement is provided in a plane that is at an angle to the plane of the dipoles wherein one or more baluns are integrated in the feed arrangement. Dual polarised operation can be performed independently between the two polarisations.

Abstract: An antenna assembly is disclosed which includes a layered structure having a planar array of antenna elements; and a feed arrangement perpendicular to the antenna elements; the layered structure further having layers over the planar array of antenna elements with holes provided therethrough to allow the feed arrangement to be connected to contacts for the antenna elements. The layered structure may include vias provided such that heat may be applied remotely to the contacts.

Abstract: A structure, and a method for modifying the design of a structure, are provided such that the structure includes features designed to reduce and preferably minimize the radar cross-section of the structure over one or more predetermined frequency ranges. A structure is provided having an inclined surface, wherein the angle of inclination is selected for which the level of radar cross section is below a local maximum in the sidelobes in each of the scattering patterns of incident electromagnetic radiation at frequencies within one or more predetermined frequency ranges. In the particular case of a tower, for example of a wind turbine, the radar cross-section of the tower may be minimized for two or more radar bands by appropriate selection of the angle of inclination of a frusto-conical portion of the tower. Ideally, the tower is constructed entirely in the form of a cone frustum.

Abstract: An absorber of electromagnetic radiation, in particular for use with microwave or millimeter wavelength radiation, comprising a conducting ground plane (205) a meta-material surface element (200) positioned substantially parallel to and at a predetermined distance from the ground plane (205) by means of an intermediate dielectric layer (210), and a resistive element substantially coincident with the meta-material surface element (200), wherein the meta-material surface element (200) comprises a plurality of at least partially conducting inclusions in the shape of square loops (300) deposited in a periodic pattern over the surface of a dielectric material and wherein the predetermined distance is selected to ensure that, in use, the meta-material surface element (200) acts as a high impedance surface to incident electromagnetic radiation. Preferably, a covering dielectric layer (215) is provided over the meta-material surface element (200).