The invention provides an image display device that has an especially satisfactory display quality for animated images, and sufficiently suppresses the irregularities of display quality among pixels. The image display device includes a light emitting drive means that drives a light emitting means, based on an analog display signal inputted to the pixels, and a light emitting control switch for controlling a light-on or light-off of the light emitting means on one end of the light emitting drive means in each pixel.

Image Display Device

The problem of reducing the size of a dual offset Cassegrain reflector type microwave antenna without adversely affecting performance while retaining the simplicity of the main reflector's (1) and subreflector's (3) traditional simple surface curvatures is solved by having the paraboloidal shaped main reflector's focal length, fm, and diameter, D, fulfil the criteria that the ratio of fm to D is less than 1.0; and in which the hyperboloidal shaped subreflector (3) is oriented so that its left foci, at which the microwave feed (5) aperture is placed, lies above the main reflector's focal axis. It's subreflector subtends an angular arc about the focal point that is slightly larger than the corresponding arc subtended by the main reflector. The elegance of the compact antenna is demonstrated by improved performance, attaining efficiencies in excess of seventy three percent.

Small volume dual offset reflector antenna

A unique single offset reflector antenna has been designed which provides as much as +or-30 degrees of scanning in azimuth while maintaining a much higher aperture efficiency than a torus antenna. Like a torus antenna, different portions of the reflector are illuminated for each scanned beam. The reflector profile curve in the plane of scan is found by least squares to minimize the error for the beams with the greatest scan angle, and then polynomial terms of up to sixth order which minimize nonplanar phase errors are added to produce a three-dimensional reflector surface. Numerical simulation indicates very good results for all 0.5 degrees beams in the +or-30 degrees azimuth field of view, with peak gain no more than 0.3 dB below ideal and highest side-lobe levels no worse than 13.3 dB below the peak gain. Additionally, comparable performance can be extended to the elevation plane out to 15 degrees /-30 degrees , although full azimuth performance becomes compromised at extreme elevation scan angles. By using an offset design, there is no blockage of the outgoing beam by the feed array assembly for azimuth scanning. With better feed performance than comparably sized paraboloids, and being more compact than similar torus reflectors, this novel antenna should find numerous uses in spacecraft and terrestrial applications. >

A high aperture efficiency, wide-angle scanning offset reflector antenna

A large number of references dealing with the geometry, static, vibration and buckling analysis of elliptic paraboloid shells exist in the literature. This review work attempts to organize and summarize the extensive published literature on the basic achievements in investigations of thin-walled structures in the form of elliptic paraboloids. Possibilities of elliptic paraboloids with reference to machine-building and construction designs and to the apparatuses used in theoretical physics are briefly considered. The geometric part of the review is extended due to consideration of optimization of surface’s sizes, researches of representation of a surface on the plane and introducing bibliographic material on fractal geometry. Several existent analytical and numeral methods of calculation of the examined shells on durability give a possibility to choose one of the methods for the solution of new twodimensional or three-dimensional tasks. Geometrical researches, approximation and bending of elliptic paraboloid surfaces, research of the stress-strain state of shells by analytical and numerical methods, natural and forced vibration of a shell, forming and setting of surfaces, application of shells in the form of elliptic paraboloids are the main problems which are considered in this review.

https://openconstructionbuildingtechnologyjournal.com/VOLUME/10/PAGE/576/PDF/

Geometry, Static, Vibration and Bucking Analysis and Applications to Thin Elliptic Paraboloid Shells

A sensor for a fill level measuring device for determining the fill level in a container by determining the delay time of high-frequency signals, comprising a main reflector having an edge region and an inner region, a sub reflector, which is connected to the edge region of the main reflector via a radome, an inner space, which is encompassed by the radome and the main reflector, and a hollow waveguide which is connected to the main reflector and has a front end, which is oriented toward the sub reflector for coupling electromagnetic waves in and/or out, wherein the radome and the sub reflector are embodied as integral or unitary in formation.

Parabolic antenna with an integrated sub reflector

An antenna designed to emit a beam of generally elliptical cross-section has a reflector with a parabolic-elliptical concave surface conforming to the formula (x/p)+(y/q)=2z where p and q are the parameters of its parabolic cross-section in the xz and yz planes, respectively. A microwave feed located on a line interconnecting the foci of these two parabolas, preferably at the outer focus separated from the surface vertex by a distance q/2, generates a beam parallel to the axis whose ellipticity depends on the ratio q/p.

Antenna having radiation pattern with main lobe of generally elliptical cross-section

Antennenreflektor mit parabolisch- elliptischer reflektorflaeche

http://ieeexplore.ieee.org/iel6/8248/25853/01147898.pdf

Analysis and synthesis of an elliptical paraboloid offset reflector antenna elliptically shaped beam antenna

The characteristics of corrugated conical horns, radiating the balanced hybrid mode HE11 have been summarized in a number of linear curves giving the beam width at different levels versus the horn flare angle (2?) and versus the radius of the horn aperture, normalized to the wavelength (? = r/?). Moreover the feed horn performance for single or double reflectors antennas, have been analysed and curves are presented for the antenna illumination efficiency (aperture efficiency by spillover efficiency) versus parameters d and a. All the curves reported are a useful basis for the antenna design and give a fast and accurate solution to the following problems: - synthesis of a corrugated conical horn with a specified amplitude radiation pattern - synthesis of a corrugated conical horn as a function of the antenna illumination efficiency.

Analysis and Synthesis of Corrugated Conical Horns

A new reflector antenna having a shaped main beam with elliptical cross section is introduced. Antennas with shaped main beams are required on board the satellite in order to save power and avoid interferences. The shape of the main beam must be such as to cover the earth zone to be served. In many cases an elliptical contour is required. Often the methods used to design a shaped main beam antenna are based on the geometrical optics theory which, as known, is not completely valid at microwave frequencies. In this paper an extensive analysis of a new elliptically shaped beam antenna is reported. The peculiarity of this antenna is the shape of the reflector which is an elliptical paraboloid. The geometry of the reflector has led to the antenna being called an ? elliptical paraboloid reflector antenna ?. For this antenna general curves have been obtained which allow a very fast and accurate design.

Enrico Pagana

Papers

Antenna having radiation pattern with main lobe of generally elliptical cross-section

Antennenreflektor mit parabolisch- elliptischer reflektorflaeche

Analysis and synthesis of an elliptical paraboloid offset reflector antenna elliptically shaped beam antenna

Analysis and Synthesis of Corrugated Conical Horns

A New Elliptically Shaped Beam Antenna