Mitsubishi Denki Kabushiki Kaisha

Other

Shuji Urasaki

Tadashi Takagi

Isamu Chiba

Noriharu Suematsu

Yoshihiko Konishi

Shigeru Makino

Yukio Ikeda

Takashi Katagi

Yoji Isota

Gen Toyoshima

Masataka Ohtsuka

Tsutomu Endo

Naofumi Yoneda

Moriyasu Miyazaki

Yoshio Inasawa

Makoto Matsunaga

Mitsuru Mochizuki

Kenji Itoh

Yuji Kobayashi

Toru Fukasawa

Tomohiro Mizuno

Yoshitaka Hara

Takayuki Nakano

Katsuhiko Aoki

Akio Iida

Hiroyuki Deguchi

Kazunari Kihira

Yasuhisa Tamagawa

Izuru Naito

Soichi Matsumoto

Yoshiyuki Chatani

Shinichi Betsudan

Motoo Mizusawa

Takashi Ebisui

Norio Miyahara

Shin-ichi Satoh

Izuru Naitoh

Youji Isota

Masahiro Kamiyama

Masato Ishiguro

Akio Iso

Katsuhisa Uno

Masanao Iimori

Shunichiro Kawabata

Rumiko Yonezawa

Disclosed is an image capturing apparatus comprising a primary mirror 1 that has a surface which is a section of a surface cut out from a paraboloid with a single focus; a secondary mirror 2 that has a surface which is a section of a surface cut out from a hyperboloid with two foci; and a photodetector 3 which converts the light signal coming from the secondary mirror 2 into an electric signal. The secondary mirror 2 is placed in a position where one of its foci and the focus of the primary mirror 1 match with each other. The photodetector 3 is placed near the other focus of the secondary mirror 2. By using two mirrors, the light from the object is led to the photodetector 3 without being shaded.

Image capturing apparatus

For the purpose of obtaining a mechanical drive reflecting mirror antenna device which is downsized and low in attitude, enables wide-angle scanning, and is high in performance, there are provided a main reflection mirror, a sub-reflection mirror, a primary radiator, a first circular waveguidewhich is connected to the primary radiator and has a plurality of bend portions, a first circular waveguide rotary jointwhich is connected to the first circular waveguide, a second circular waveguidewhich is connected to the first circular waveguide rotary joint and has a plurality of bend portions, and a second circular waveguide rotary jointwhich is connected to the second circular waveguide and is different in a direction of a rotary axis from the first circular waveguide rotary joint by substantially 90 degrees.

Antenna device for conducting two-axial scanning of an azimuth and elevation

There are disposed four antenna elements which are arranged circumferentially at regular intervals, and four 90-degree hybrids each having four terminals, two 90-degree hybrids which are arranged in parallel are connected in two stages, only one of the output terminals of an upstream 90-degree hybrid and only one of the input terminal of a downstream 90-degree hybrid cross each other and are connected to each other, and the four output terminals of the two downstream 90-degree hybrids and the four antenna elements are connected to each other; the passing phase between the terminals that cross each other within the respective 90-degree hybrids is set to 0 degree, and the passing phase between the terminals that are in parallel within the respective 90-degree hybrids is set to 90 degrees. As a result, the structure of the feed circuit can be simplified, and plural kinds of beams can be formed.

Simplified feed circuit for an array antenna device

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.

Reflector antenna

A directivity control of an adaptive antenna is performed for an antenna of a base station when a signal is received in the antenna of the base station, and the directivity control of the adaptive antenna is performed for an antenna of a mobile station when a signal is received in the antenna of the mobile station. Therefore, even though an antenna of a second mobile station functions as an interference wave source, the reception of an interference wave from the interference wave source can be prevented in both the antenna of the base station and the antenna of the mobile station, and a communication quality in both the base station and the mobile station can be maintained in the communication between the base station and the mobile station.

Mobile communication system and communication method performed in the system

A plurality of concentric circle array antennas each having a different radius are disposed on an identical plane, and a plurality of element antennas are arranged circumferentially in each of the concentric circle array antennas. The plurality of concentric circle array antennas are arranged at regular intervals d in most part thereof, and the concentric circle array antennas corresponding to a remaining part of the plurality of concentric circle array antennas are arranged at intervals d&plusmn;0.4 to 0.6d. The radii of the part of plural concentric circles change by &plusmn;(0.4 to 0.6)d, so that it is possible to reduce a wide-angle side lobe.

Antenna device

An antenna mirror surface measuring/adjusting apparatus has a plane mirror larger than an aperture surface of said principal reflection mirror and set in parallel with the aperture surface, an actuator for driving a group of mirror surface panels of the principal reflection mirror, and a receiving electric field arithmetic processor for measuring, each time the actuator shifts a position of the mirror surface panel from an initial state of the mirror surface panel of the principal reflection mirror, radio wave signals of radio waves radiated by a transmitter/receiver and reflected back from the plane mirror, obtaining an aperture surface phase distribution in an initial state of the principal reflection mirror by executing an arithmetic process on these measured signals, then gaining configurations of the mirror surface on the basis of the aperture surface phase distribution, and adjusting the mirror surface by the actuator in accordance with the obtained mirror surface configurations. Accordingly, a measurement frequency is freely selected, and the measurement can be carried out in an ideal measurement environment of not being influenced by changes in wind, sunlight and temperature, whereby the mirror surface can be adjusted with high accuracy.

Antenna mirror surface measuring/adjusting device

A composite antenna apparatus comprising a balun connected to an inner conductor at the upper end of a coaxial line,, one end of a helical element formed by a pair of wire conductors is connected to the balun, the other end is wound symmetrically around the coaxial line using the the coaxial line as a center so as to face the balun and is connected to the outer conductor,at the lower end of the coaxial line. The provision of an outer conductor connecting terminal connected to the outer conductor and an inner conductor connecting terminal connected to the inner conductor at the lower end of the coaxial line, allows the formation, on the same axis, of a helical antenna fed by the coaxial line via the helical element and a monopole antenna formed by the outer conductor of the coaxial line. Thereby equivalent gain in the horizontal plane and a reduction in the occupied volume is achieved.

Composite antenna apparatus

Antenna apparatus for portable phones

A mobile satellite communication system including an artificial satellite which is situated in a satellite orbit and develops an active phased array antenna so as to accomplish a line to a terrestrial station using a portable terminal in a specific area. As a result, a service that satisfies a demand for communication in the specific area can be realized.

Mobile satellite communication system

A non-driven first linear element is disposed in the vicinity of an inverted-F second linear antenna element. The driven second linear element is disposed over a conductive plate having a flat shape, in such a manner as to be substantially parallel to the inverted-F antenna. The non-driven element has a short-circuited end of the inverted-F antenna, and has substantially the same resonant frequency as that of the inverted-F antenna.

Antenna apparatus

Herein is revealed a helical antenna apparatus wherein the direction of beam radiation hardly changes even if the frequency in use changes. Two helical antennas which are wound with two conductive wires spirally, respectively, at equal intervals with a specified pitch .alpha. in the form of a cylinder are disposed along the length of the helical antennas so that the axes thereof substantially coincide with each other. By determining the lengths of the feeders of the respective helical antennas appropriately in order to set the phase of supplied power, it is possible to form the beam of signals radiated into space in the shape of conical beam having a directivity oriented obliquely upward. Additionally, it is possible to obtain the conical beam in which the direction of beam radiation does not change even if the frequency in use is changed.

A frequency synthesizer, including a direct digital synthesizer (DDS) for providing wave amplitude data as a standard signal source, and a phase lock loop for comparing a branched synthesizer frequency with the standard signal source at a phase comparator. A frequency converter converts the output frequency of the DDS to a higher frequency and provides the resultant higher frequency to the phase comparator in the phase loop. A small loop dividing ratio is obtained by converting the low frequency of the DDS to a higher frequency. A spurious of the synthesizer output signal is reduced and provides a low power consumption apparatus.

Frequency synthesizer

In an amplifying feedback-type FET semiconductor element for use as a wide-band microwave amplifier in telecommunications system such as a radar, a monolithic IC feedback circuit is located between at least two parallel FET cells of an FET semiconductor element and also between gate and drain lead electrodes of the FET semiconductor element. The feedback circuit includes at least two connecting lines and at least one passive element and is connected to the two lead electrodes. With this arrangement, it is possible to reduce the total length of said connecting lines to a minimum, thus guaranteeing a frequency characteristic showing a flat gain over a wide band.

Amplifying feedback FET semiconductor element

A low-distortion radio-frequency amplifying apparatus is equipped with a distortion compensating circuit for generating a distortion signal which cancels a distortion generated during radio-frequency amplification. The apparatus detects a signal corresponding to an envelope power of the output or input of an amplifier, varies a distortion compensating characteristic according to the power value, and compensates a distortion over a wide dynamic range. The apparatus includes a detector for detecting an envelope detection signal of the amplifier, and a controller for compensating the distortion compensating characteristic according to the detected signal.

Low-distortion radio-frequency amplifying apparatus

Growing community of inventors

Tokyo, Japan

Shuji Urasaki