Fresnel zone

About: Fresnel zone is a research topic. Over the lifetime, 2337 publications have been published within this topic receiving 37650 citations.

Two-dimensional Fresnel solar energy concentration system

Abstract: The present invention provides a solar energy concentrating reflection system comprising multiple arrays of solar reflectors arranged adjacent to one another on a generally planar support structure where each of the reflector arrays configured into a first Fresnel array in a first dimension. Each of the first Fresnel array of reflectors are in turn arrayed and supported in a support frame in a configuration of second Fresnel arrays in a second dimension such that solar energy from the sun is reflected and concentrated to a predetermined focal line. A solar receiver is disposed in the focal line of the configured solar reflectors such that the first and second Fresnel arrays uniformly reflect and concentrate solar energy from the sun onto the solar receiver within the first and second dimensions with a uniform solar intensity profile.

Detector for inclination of plane plate

Abstract: PURPOSE:To measure the inclination of a mask stably with a simple constitution, by irradiating an array of Fresnel zones, which is formed on the rear face of the mask, with rays and observing an optical image converged by the reflected light of a wafer. CONSTITUTION:Eight Fresnel zone plates similar to a zone plate 13-8 are arranged on the rear face of a mask 11 to form one set of a zone array 13. When the mask 11 is irradiated with a parallel light from above, the third-order focus of the zone array 13 is observed as a light spot by the reflected light from a wafer 12. If the mask 11 and the wafer 12 are parallel with each other, only a light spot 16 looks bright. If the wafer 11 is inclined, plural zone plates have bright centers. Thus, the inclination of the wafer 11 is measured stably with a simple constitution.

Synthesis and analysis of a planar waveguide array with two-dimensional frequency scanning focused in the Fresnel zone

Abstract: A 2D array of radiators with raster frequency scanning focused in the Fresnel zone is presented. The problem of determining the radiator positions for field focusing at a finite distance from the array plane is solved. An approximate matrix model of the array antenna describing its properties as a microwave multiport and allowing determination of the distribution of radiation sources in the array aperture is proposed. The problem of improvement of the array matching in scanning ranges is considered. An approximate model describing radiation from the array is built. This model is used for determining the position and shape of the scanning surface and the field distribution inside the focal spot as well as for the analysis of the dynamics of the field maximum in the frequency scanning sector.

Device for application of coating on dielectric in discharge

Abstract: FIELD: machine building. ^ SUBSTANCE: proposed device comprises vacuum chamber, electric arc evaporator, backing to support the part connected with power supply negative terminal and insulator arranged on said backing and provided with protective case and insulated shield arranged between said evaporator and protective case. Note here that said shield is made up of alternating transparent and opaque concentric rings. Outer radii of said rings Rm correspond to Fresnel zones and are defined by formula where a - is distance from evaporator to electrically insulated shield, b is distance from the latter to part being processed, m is number of concentric ring corresponding to Fresnel zone, is associated wavelength of ion in evaporated coating. Diameter of said shield equals maximum size of part projection on aforesaid backing. ^ EFFECT: higher adhesion, density and strength. ^ 3 cl, 2 dwg