An impedance matching film 10a has a plurality of openings 11. The plurality of openings 11 are formed at equal intervals in a specific direction along main surfaces 10f of the impedance matching film 10a. The impedance matching film 10a has a sheet resistance of 300 to 700Ω/□. A size G of each opening 11 in the specific direction is 50 μm or more and 1000 μm or less. In the impedance matching film 10a, a cross-sectional resistance value R.sub.s is 1MΩ/m or more. The cross-sectional resistance value R.sub.s is determined by dividing a specific resistance of a material forming the impedance matching film 10a by a product of a thickness of the impedance matching film 10a and a distance between the nearest openings 11.

An antenna and an electronic device are provided. The antenna includes: a radiating element pair, including a first radiating element and a second radiating element that are arranged in an annular array, where the first radiating element and the second radiating element are symmetrically arranged with respect to a symmetry line, the symmetry line passes through a center point of the annular array, and the first radiating element or the second radiating element is in an arc shape centered on the center point, or extends in a tangent direction of an arc shape centered on the center point; and a feed structure, including a first feed part and a second feed part, where the first feed part is coupled to the first radiating element, and the second feed part is coupled to the second radiating element.

An antenna and an electronic device are provided. The antenna includes: a radiating element pair, including a first radiating element and a second radiating element that are arranged in an annular array, where the first radiating element and the second radiating element are symmetrically arranged with respect to a symmetry line, the symmetry line passes through a center point of the annular array, and the first radiating element or the second radiating element is in an arc shape centered on the center point, or extends in a tangent direction of an arc shape centered on the center point; and a feed structure, including a first feed part and a second feed part, where the first feed part is coupled to the first radiating element, and the second feed part is coupled to the second radiating element.

In one embodiment of the present disclosure, an antenna assembly includes a plurality of layers defining an antenna assembly including a plurality of PCB layers and a plurality of non-PCB layers, the antenna assembly having a top surface and a bottom surface, and adhesive coupling between the PCB layers and the non-PCB layers.

A radio wave absorber includes a resistive layer, an electroconductive layer, and a dielectric layer. The resistive layer has a first main surface with a plurality of first openings formed at equal intervals. The electroconductive layer has a second main surface with a plurality of second openings formed at equal intervals. The dielectric layer is disposed between the resistive layer and the electroconductive layer. In the radio wave absorber, a value obtained by dividing a larger value out of a first ratio and a second ratio by a smaller value out of the first ratio and the second ratio is 1.3 or more. The first ratio is a ratio (G.sub.R/W.sub.R) of a size G.sub.R of the first opening to a distance W.sub.R between the first openings. The second ratio is a ratio (G.sub.C/W.sub.C) of a size G.sub.C of the second opening to a distance W.sub.C between the second openings.

An array antenna (A) in a medium (M) comprises a plurality of radiating elements (ER.sub.T) ensuring the transition between the antenna and the medium, the reflectivity of each element depending on a parameter, the reflectivity of a first element being close to that of the medium, the reflectivity of a last element being close to that of the antenna, the reflectivity parameter of the elements varying from one element to the next. A method comprises calculation of a path equal to the sum of the variations of the reflectivity from one element to the next element, optimization of the variation of the reflectivity parameter so that equivalent radar cross-section of the antenna is the lowest possible or the antenna best observes the radiation objectives, determination of the different elements as a function of said parameter, and simulation of the overall reflectivity and/or of the radiation of the antenna.

An individually formed radiating unit, an antenna array, and an antenna assembly are provided. The individually formed radiating unit includes a reflector, at least one radiating element integrated into a first side of the reflector, and a housing disposed on a second side of the reflector. The housing forms a chamber for housing a feed network

A dielectric substrate for RF, microwave, or millimeter wave devices, circuits, or surfaces includes a propagating region for transmitting or reflecting an electromagnetic field, and one or more material-filled vias located within the propagating region. The application of an external electric or magnetic field to the material-filled vias may be used to tune the electric permittivity or the magnetic permeability of the fill material and hence control the effective electric permittivity or the effective magnetic permeability of the dielectric substrate within the propagating region. A dimension of the material-filled vias may be less than half of a wavelength of the propagating electromagnetic field. The fill material may include liquid crystals, a ferroelectric crystal composite, a ferromagnetic crystal composite, organic semiconductors, and/or electro-optic or magneto-optic polymers.

A dielectric substrate for RF, microwave, or millimeter wave devices, circuits, or surfaces includes a propagating region for transmitting or reflecting an electromagnetic field, and one or more material-filled vias located within the propagating region. The application of an external electric or magnetic field to the material-filled vias may be used to tune the electric permittivity or the magnetic permeability of the fill material and hence control the effective electric permittivity or the effective magnetic permeability of the dielectric substrate within the propagating region. A dimension of the material-filled vias may be less than half of a wavelength of the propagating electromagnetic field. The fill material may include liquid crystals, a ferroelectric crystal composite, a ferromagnetic crystal composite, organic semiconductors, and/or electro-optic or magneto-optic polymers.

Apparatus and methods useful in surveying to provide information rich models. In particular, information not readily or possibly provided by conventional survey techniques can be provided. In some versions targets provide reference for baseline positioning or improving position information otherwise acquired. Scanning may be carried out in multiple locations and merged to form a single image. Machine mounted and hand mounted scanning apparatus is disclosed.