Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Izuru Naito

Yoshihiko Konishi

Shinichi Yamamoto

Toshiyuki Horie

Hiroyuki Sato

Naofumi Yoneda

Moriyasu Miyazaki

Yoshio Inasawa

Izumi Mikami

Kenji Kusakabe

Shigeru Makino

Shuji Nuimura

Tomohiro Mizuno

Shuji Urasaki

Tamotsu Nishino

Akio Iida

Hiroyuki Satou

Kazuyuki Takada

Yoji Aramaki

Makio Tsuchiya

Yutaka Simawaki

Shinji Kuroda

Syuji Nuimura

An antenna device including: a reflector antenna including a primary radiator, a feed waveguide for feeding radio waves to the primary radiator, and a reflector; and a radome that covers the reflector antenna, in which the antenna device further includes a sidelobe reduction member attached to a vicinity of the primary radiator or the feed waveguide, the sidelobe reduction member reducing a sidelobe in a specific direction of an antenna by at least one of scattering and absorbing of radio waves reflected by the radome out of the radio waves radiated from the reflector antenna. Therefore, it is possible to reduce a sidelobe deterioration caused by reflection waves from the radome.

Antenna device

Radome equipment that includes an antenna device, and a radome that protects the antenna device by housing the antenna device therein and that transmits electric power necessary for communication, in which: a matching layer made of a single-layer dielectric is attached to an inner surface of the radome; and the matching layer has a thickness that is set to a value that minimizes reflection based on an impedance estimated from an interface between the matching layer and the radome before the matching layer of the radome is attached, a characteristic impedance of a medium of the matching layer, a wavelength in the matching layer, and a characteristic impedance of a medium of a space in which the radome is disposed.

Radome equipment

A beam forming apparatus of a satellite is configured to: define a perimeter of a coverage area, and define a coordinate grid of a polar coordinate system so as to divide the coverage area into a plurality of small areas; calculate coordinates of borders between basic cells in a Cartesian coordinate system, the basic cells being shaped into regular hexagons arranged to be in contact with one another along their sides and at their vertices or into circles circumscribing the regular hexagons; define a plurality of new cells by converting, through coordinate transformation, the coordinates of the borders between the basic cells in the Cartesian coordinate system into coordinates of borders in the polar coordinate system; and set amplitudes and phases to the plurality of antenna devices that are suitable to form a plurality of beams in respective directions of the plurality of new cells.

Satellite communication system and method for dividing the coverage area thereof

The present invention aims at providing a rotary joint which is of a thin type and has broad band characteristics and which is low in loss and is excellent in power resistance as well. In order to attain the object, the rotary joint includes: first and second polarizers each having a common side terminal connected to a waveguide portion, and two branch side terminals through which two polarized waves orthogonal to each other inputted through the common side terminal are separately taken out; and the waveguide portion which has a rotatable connection portion, one end of which is connected to the common side terminal of the first polarizer and the other end of which is connected to the common side terminal of the second polarizer.

Rotary joint

A reflector antenna device includes: an auxiliary reflectorthat receives an electric wave radiated from an opening portion by a primary radiatorand reflects the electric wave; and a main reflectorthat receives the electric wave that is reflected by the auxiliary reflectorand radiates the electric wave to a space. In the reflector antenna device, the configurations of the auxiliary reflectorand the main reflectorare designed such that an electric power in an area of the main reflectorwhere the auxiliary reflectoris projected on the main reflectorin parallel with the radiating direction of the electric wave due to the main reflectoris equalor lower than a predetermined first threshold value, and a radiation pattern of the antenna which is determined by the area of the main reflectorother than the area has a desired characteristic.

Reflector antenna

In order to lessen the deterioration of the VSWR, a plural-reflector antenna system is provided wherein an appropriately shaped vertex matching plate is disposed on the subreflector and electric waves that reenter the primary radiator are cancelled out. The electric waves radiated from the primary radiator are reflected by the subreflector and are radiated into space after being reflected by the main reflector. The passing area in the horn aperture, through which the reflected waves from the vertex matching plate pass, is made to be analogous to the aperture of the primary radiator, by defining the vertex matching plate as an ellipsoid, and by orienting its minor-axis direction in the major-axis direction of the main reflector and its major-axis direction, in the minor-axis direction of the main reflector.

Plural-reflector antenna system

In order to provide a reflector antenna apparatus which can be installed within a small space, which has adequate practicality, and which can perform scanning by pivoting about two axes which are perpendicular to each other, in a reflector antenna apparatus having a Cassegrain reflector and a rotating mechanism which rotates the reflector about an azimuth axis and an elevation axis, a reflector with a substantially rectangular aperture has its elevation axis passing through substantially the central portion of the height dimension of the reflector, and reflector surface adjustment is carried out such that substantially all of the electromagnetic waves which are supplied are received and reflected, whereby the antenna height does not become large when the reflector rotates about the elevation axis. The reflector may be an array of a plurality of reflector elements.

High-output transmitters are applied to a power generation satellite and a transmission antenna apparatus and a transmission antenna having an array antenna with a small number of element antennas and a reflecting mirror antenna is applied, thereby providing a power generation satellite and a transmission antenna apparatus in a space photovoltaic generation system comprising transmission antennas each having performance equivalent to that of a phased array antenna with a smaller number of transmitters and a smaller number of element antennas than those of a transmission antenna implemented as a phased array antenna.

Power generation satellite and transmission antenna apparatus

A power generation satellite has a photoelectric conversion unit for converting sunlight into electric energy, a transmission frequency conversion unit for performing frequency conversion of the electric energy to a microwave, a microwave control unit for controlling the amplitude, the phase, or the amplitude and the phase of the microwave, and a transmitting antenna for radiating the microwave. A plurality of the power generation satellites are placed in space to form a power generation satellite group and an array antenna having the transmitting antennas of the power generation satellites in the power generation satellite group as element antennas is formed.

Growing community of inventors

Tokyo, Japan

Izuru Naito