Showing papers on "Parabolic reflector published in 1972"
Patent•
06 Jul 1972
TL;DR: A lamp arrangement for medical operating rooms is described in this paper, where light from a point source is focused by a spheroidal reflector on the inlet end of a light pipe, which transmits it to a reflector arrangement below.
Abstract: A lamp arrangement for medical operating rooms. Light from a point source is focused by a spheroidal reflector on the inlet end of a light pipe, which transmits it to a reflector arrangement below. In one embodiment a straight light pipe is employed with a stepped prismatic element to direct the light upward onto a stepped reflector. In an alternate embodiment a curved light pipe is employed to transmit the light directly onto a parabolic reflector. The light rays leaving the final reflector in both embodiments are parallel and of uniform intensity.
43 citations
Patent•
06 Nov 1972
TL;DR: In this paper, a multiple-input multiple-output (MIMO) antenna with individually fed illuminators placed in a predetermined configuration with respect to each other and to a single parabolic reflector is used to produce a highly directional microwave radiation pattern.
Abstract: A multiple feed microwave antenna. Individually fed illuminators are placed in a predetermined configuration with respect to each other and to a single parabolic reflector and are fed with predetermined current values so as to produce a highly directional microwave radiation pattern. The radiation pattern is relatively broad and contains a plurality of discrete areas of information, distinguished by different carrier and modulating frequencies. By varying the number of illuminators and their separation, fine control over the beamwidth and the shape of the directional radiation pattern may be obtained.
14 citations
Patent•
17 May 1972
TL;DR: In this article, a Q-switch was proposed for use in the optical system of a laser which achieves a high repetition rate by using a central rotating reflector and a single spherical reflector.
Abstract: A Q-switch for use in the optical system of a laser which achieves a high repetition rate by using a central rotating reflector and a single spherical reflector. If the intersection of the axis of rotation and surface of the central reflector is exactly on the center of the spherical reflector, a beam entering on the axis of rotation and focused on the spherical reflector will be constantly retro-reflected while the central reflector rotates about its rotational axis.
6 citations
5 citations
TL;DR: In this paper, the profile of a secondary mirror was derived to compensate for errors with long correlation lengths on the surface of a parabolic reflector 2.8 m in diameter.
Abstract: The profile of a secondary mirror has been figured to compensate for errors with long correlation lengths on the surface of a parabolic reflector 2.8 m in diameter. At 34 GHz, a gain improvement of 2.9 dB was obtained, with a corresponding decrease in the sidelobe level close to the main beam.
5 citations
TL;DR: In this paper, the cross polarizing effects introduced by a uniform water film on the surface of a parabolic reflector were evaluated at 10 and 34 GHz, where the reflector was considered to be illuminated by an isotropic linearly polarized source at the focus, but the analysis can be applied for any given primary feed aperture field distribution.
Abstract: The cross polarizing effects introduced by a uniform water film on the surface of a parabolic reflector are evaluated at 10 and 34 GHz. The reflector is considered to be illuminated by an isotropic linearly polarized source at the focus, but the analysis can be applied for any given primary feed aperture field distribution. The aperture cress polarized field is obtained, and a worst case diffraction field (when opposite quadrants of the reflector are wet) is then calculated. A relatively low level cross polarizing effect is predicted, dependent on diameter-to-focal-length ratio.
3 citations
20 Dec 1972
TL;DR: In this paper, the authors measured the acoustic radiation patterns from acoustically soft parabolic reflectors driven by a line source coincident with the focal lines of the reflectors were measured in the NRL Acoustic Research Tank Facility to verify a mathematical model of an ideal paraboliccylinder reflector.
Abstract: : The acoustic radiation patterns from acoustically soft parabolic reflectors driven by a line source coincident with the focal lines of the reflectors were measured in the NRL Acoustic Research Tank Facility to verify a mathematical model of an ideal parabolic-cylinder reflector. Data taken in the near and far fields of the reflectors at various frequencies between 10 kHz and 40 kHz were plotted together with the theoretically predicted radiation patterns. Agreement is good between theory and experiment. The experiment was performed with a shallow reflector (4.0-inch focal length and 28.3-inch aperture) and with a deep reflector (2.0-inch focal length and 28.4-inch aperture), and all measurements were made in the median planes of the reflectors. Emphasis was placed on careful construction of the parabolic reflectors and precision alignment of the line source. Error analyses were performed to determine the parabolicness of the reflectors and the effect on the radiation pattern of a slight misalignment of the line source. To illustrate the use of the mathematical model as a design tool, curves were plotted showing the reflector performance characteristics as a function of the reflector parameters. (Author)
1 citations