M. Mizusawa

Bio: M. Mizusawa is an academic researcher from Mitsubishi Electric. The author has contributed to research in topics: Cassegrain antenna & Periscope antenna. The author has an hindex of 4, co-authored 5 publications receiving 93 citations.

A beam-waveguide feed having a symmetric beam for Cassegrain antennas

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.

Volume-type holographic antenna

Abstract: A new type of holographic antenna based on the principle of the volume hologram is proposed. The characteristics of the prototype are examined. The antenna has a unidirectional beam with a front-to-back ratio of 20 dB. The practical frequency handwidth is about 10 percent of the center frequency. The antenna is unique in that the feed point is placed in the plane of the holographic plate so that both feeder and the holographic plate could be made out of one printed circuit board for easy flush mount installation or mass production, although the feeder of the prototype antenna was a pyramidal horn.

A dual doubly curved reflector antenna having good circular polarization characteristics

Abstract: A new type of shaped-beam radar antenna having good polarization characteristics is described. This antenna is composed of a dual doubly curved reflector system and a feed horn with good axial ratio, such as a dual-mode horn. The rotationally symmetrical beam of the feed horn can be converted into a shaped beam by the reflector system without degradation of the axial ratio. The design of this type antenna is discussed and the experimental results of a model antenna with a cosecant squared beam are shown. Integrated cancellation ratio of the model was 22 dB.

Quasi-optical techniques

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 >

Offset-parabolic-reflector antennas: A review

Abstract: Although used for some decades, the offset-parabolicreflector antenna's electrical properties and performance were not accurately modeled and optimized until the 1960's. This paper reviews, in a tutorial fashion, the state of the art of this important antenna for readers who are not necessarily experts in antenna theory and technology. After a discussion of fundamentals, the performances of both single- and double-reflector configurations are treated and compared, and practical primary feeds are described. Comments are given on the present status of analysis and design and on problems to be solved.

Surface scattering antennas

Abstract: Surface scattering antennas provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the scattering elements are complementary metamaterial elements. In some approaches, the scattering elements are made adjustable by disposing an electrically adjustable material, such as a liquid crystal, in proximity to the scattering elements. Methods and systems provide control and adjustment of surface scattering antennas for various applications.

Optical Huygens' Metasurfaces with Independent Control of the Magnitude and Phase of the Local Reflection Coefficients

Abstract: Implementation of abrupt phase discontinuities along a surface has been the theme of recent research on electromagnetic metasurfaces. Simple functionalities such as reflecting, refracting, or focusing plane waves have been demonstrated with devices featuring phase discontinuities, but optical surfaces allowing independent magnitude and phase control on the scattered waves have yet to emerge. In this paper, we propose the first true optical Huygens’ surface, which explicitly utilizes orthogonal electric and magnetic responses to realize total control on an optical surface’s local reflection coefficients. This extends the functionality of metasurfaces to an unprecedented level. We first demonstrate that a nanorod gap-surface plasmon resonator can act as a Huygens’ source. Thereafter, by properly tuning and rotating these resonators, we realize arbitrary reflection optical metasurfaces—surfaces for which the local reflection coefficients can be independently tailored in both magnitude and phase. We demonstrate the versatility of this approach through designs of a metasurface that asymmetrically reflects two copolarized beams and a Dolph-Tschebyscheff optical reflectarray.

Offset multireflector antennas with perfect pattern symmetry and polarization discrimination

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.