Mitsubishi Denki Kabushiki Kaisha

Nippon Telegraph and Telephone Public Corporation

Motoo Mizusawa

Shinichi Betsudan

Shuji Urasaki

Fumio Takeda

Tadashi Takano

Shigeru Sato

Chikao Kinoshita

Sigeru Sato

Masanao Iimori

Toshio Satoh

An multi-frequency antenna feed system has a corrugated conical horn and a diplexer interconnected serially to be operative in two frequency bands represented by frequencies f.sub.H and f.sub.L corresponding to wavelengths .lambda..sub.H and .lambda..sub.L respectively, where 2f.sub.L .ltoreq.f.sub.H. Corrugated grooves on the inner surface of the conical horn have the depth h, where .lambda..sub.L /4&lt;h&lt;.lambda..sub.L /2. The corrugated conical horn has the inside diameter at its reduced diameter end which is not less than 2.6.lambda..sub.o, where .lambda..sub.o designates a wavelength at which the depth of the corrugated grooves ranges from three quarters of the wavelength and one complete wavelength.

Multiple frequency antenna feed system

A subreflector and reflectors in a primary radiation system, these constituting an offset dual-reflector aerial, are subjected to the so-called reflector-surface shaping. The main reflector is formed as a part of a revolutional paraboloid, and is a combination of a number of congruent reflector-segments. With such an arrangement, the manufacturing cost of a large-sized main reflector is reduced. The production error, and the aerial gain reduction and the deterioration of a wide-angle directivity due to the production error are minimized.

Offset dual-reflector aerial having tapered reflector segments in main

An aerial system (antenna system) comprises

Cassegrainian antenna with beam waveguide feed to reduce spillover

A reflector antenna used for radar, etc, has a subreflector so as to give a relatively large aperture diameter for a primary radiator, and to decrease the effect of the outer atmosphere. A subreflector having a different curvature in a vertical plane than a curvature in a horizontal plane is provided whereby an antenna having a different beam width in the vertical plane to that in the horizontal plane is provided even though a primary radiator having a rotationally symmetrical beam is employed.

Reflector antenna having main and subreflector of diverse curvature

Growing community of inventors

Kamakura, Japan

Motoo Mizusawa