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Author

T. Kitsuregawa

Bio: T. Kitsuregawa is an academic researcher from Mitsubishi Electric. The author has contributed to research in topics: Cassegrain antenna & Slot antenna. The author has an hindex of 2, co-authored 7 publications receiving 43 citations.

Papers
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Journal ArticleDOI
01 Jan 1972
TL;DR: In this paper, the asymmetric reflectors are unavoidable in the composition of a beam-waveguide feed and generally cause asymmetry of the beam from the feed, and a rotationally symmetric beam can be obtained on the basis of geometrical optics.
Abstract: The asymmetric reflectors are unavoidable in the composition of a beam-waveguide feed and generally cause asymmetry of the beam from the feed. By means of the combination of two suitable asymmetric reflectors a rotationally symmetric beam can be obtained on the basis of geometrical optics.

39 citations


Cited by
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Journal ArticleDOI
Paul F. Goldsmith1
01 Nov 1992
TL;DR: The basic theory of quasi-optical Gaussian beam propagation and beam transformation by simple optical elements is summarized, and coupling to and between Gaussian beams is briefly discussed Guidelines for Gaussian optics system design are reviewed, the most important being beam truncation and matching Passive components in the terahertz frequency range based on quasioptical propagation, including polarization processors, filters, diplexers, and ferrite devices, are examined as mentioned in this paper.
Abstract: The basic theory of quasi-optical Gaussian beam propagation and beam transformation by simple optical elements is summarized, and coupling to and between Gaussian beams is briefly discussed Guidelines for Gaussian optics system design are reviewed, the most important being beam truncation and matching Passive components in the terahertz frequency range based on quasi-optical propagation, including polarization processors, filters, diplexers, and ferrite devices, are examined Some active quasi-optical devices, including multielement oscillators, frequency multipliers, and phase shifters, are described Some specific applications of quasi-optical systems are briefly described >

312 citations

Journal ArticleDOI
TL;DR: In this paper, the authors derived conditions that are useful for designing reflector antennas with excellent cross-polarization discrimination, provided a suitable feed such as a corrugated horn is employed.
Abstract: Conditions are derived that are useful for designing reflector antennas with excellent cross-polarization discrimination. These conditions ensure circular symmetry and absence of cross-polarization everywhere in the far field of an antenna, provided a suitable feed such as a corrugated horn is employed. The spherical wave radiated by the fundamental mode of such a feed has circular symmetry around the axis, and it is everywhere free of cross-polarization. An arbitrary sequence of N confocal reflectors (hyperboloids, ellipsoids, paraboloids) is combined with such a feed. It is shown that it is always possible to ensure circular symmetry (and absence of cross-polarization) in the antenna far field by properly choosing the feed axis orientation. If the final reflector is a paraboloid, a simple geometrical procedure can be used. It is also shown that the asymmetry caused by an arbitrary number of reflections can always be eliminated by properly introducing an additional reflection. An application to the problem of producing a horizontal beam using a vertical feed is discussed. Two arrangements are described that may be useful for radio relay systems.

148 citations

Journal ArticleDOI
TL;DR: Reflector antennas have been used since the radio pioneering era of Lodge, Hertz, and Marconi, but it took the exigent demands of radar in World War II to stimulate a real development in the reflector art as discussed by the authors.
Abstract: Reflector antennas have been used since the radio pioneering era of Lodge, Hertz, and Marconi, but it took the exigent demands of radar in World War II to stimulate a real development in the reflector art. Subsequent interest in the science of radio astronomy and the inception of microwave ground communication links were responsible for a burgeoning growth in the field, so that in the 1940s and 1950s the design principles and requirements for prime focus fed systems were well established. Cassegrain, or secondary focus systems, and horn reflectors came into prominence in the early 1960s with the advent of satellite tracking and communication networks. The desire to maximize the gain, or the gain-temperature ratio, then led to development of sophisticated techniques for properly shaping the illumination over the reflector aperture in order to maximize efficiency and minimize spillover, among them being the shaping of the sub-reflector in Cassegrain systems and the use of multimode and hybrid mode feed horns. Not all reflector antennas utilize paraboloidal surfaces. Some recent developments in line source feeds make the spherical reflector attractive for scanning applications and the conical reflector for deployable, space-borne antennas. The large 1000-foot diameter reflector at Arecibo is a well known example of the former. Although some extremely large spaceborne reflector antennas have been proposed and studied, the largest now in use appears to be the unfurlable 30-foot reflector carried by ATS-6. Finally, some gain comparisons are given for a few of the (electrically) largest reflectors that have been built both for radio astronomy and for space communications. If some milestones in reflector development have been overlooked it is due to the limitations inherent in a review paper.

73 citations

Journal ArticleDOI
T. Chu1
23 May 1983
TL;DR: In this article, a pseudo-frequency independent beam waveguide feed has been designed and built to accommodate a new liquid-helium-cooled millimeter wave radio astronomy receiver in the side cab of the Crawford Hill 7-m antenna.
Abstract: A pseudo-frequency-independent beam waveguide feed has been designed and built to accommodate a new liquid-helium-cooled millimeter wave radio astronomy receiver in the side cab of the Crawford Hill 7-m antenna. This enables the antenna to be tilted without tilting the liquid-filled receiver. Comparison with the old vertex-cab feed indicates very little measured transmission loss through the beam waveguide. The frequency independence is based upon the Fresnel zone imaging principle. Design procedures and practical bandwidth limitations are explained. An explicit expression for the third-order term of an offset reflector surface clarifies the approximation of a lens by an offset reflector.

65 citations

Journal ArticleDOI
Adel A. M. Saleh1, R. Semplak1
TL;DR: In this paper, the theory and performance of a quasi-optical Fabry-Perot diplexer employing two rectangular meshes and capable of polarization independent operation at large angles of incidence are presented.
Abstract: The theory and performance of a quasi-optical Fabry-Perot diplexer employing two rectangular meshes and capable of polarization-independent operation at large angles of incidence are presented. The diplexer is suitable for use in a dual-polarization dual-frequency beam feed system for millimeter-wave antennas. An experimental diplexer operating at an angle of incidence of 56.5\deg \pm 1\deg was found to separate two 1.1-GHz bands centered at 21 and 31.5 GHz with a loss of less than 0.3 dB in either band and a cross-polarization discrimination of more than 40 dB in the higher band and 30 dB in the lower band.

28 citations