Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Hiroshi Araki

Shigeru Oho

Akira Endo

Minoru Maeda

Katsuyuki Imoto

Masayoshi Kameyama

Yasushi Ikuta

Masahiro Matsumoto

Hisao Sonobe

Kouji Kitano

Junichi Makino

An integrated multi-layered microwave circuit includes a substrate which is constituted by dielectric layers and conductive layers laminated alternately. The conductive layer disposed at one major surface of the substrate forms a micro strip line which constitutes an antenna portion. The conductive layer disposed at the other major surface of the substrate forms a circuit pattern including a grounding line and a power source line, and then the circuit pattern forms a communication portion together with discrete parts incorporated in the circuit pattern. One of the intermediate conductive layers of the substrate constitutes a grounding layer and the other thereof constitutes a power source layer. In the substrate, a feeding via hole, a via hole for a power source, and a grounding via hole are formed so as to penetrate the substrate. Conductors are formed on the inner walls of the substrate forming the feeding via hole, the via hole for the power source, and the grounding via hole by the plating technique, respectively, whereby the antenna portion, the power source layer and the grounding layer are electrically connected to the communication portion, the power source line and the grounding line, respectively. The antenna portion is provided with a feeding land connected to the conductors of the feeding via hole, three radiators each having a circular configuration formed by the micro strip line, and a phase shifter formed by the micro strip line for connecting the respective radiators to the feeding land.

Integrated multilayered microwave circuit and a method of fabricating it

Integrated multilayered microwave circuit

An optical star coupler having a biconically tapered optical star coupler suspensively inserted in a protection tube and the method for manufacturing the same are disclosed, and the manufacturing method is that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby to form a twisting, fusing and pulling portion, and both ends of the protection tube are sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, naturally in the case of an optical star coupler using multi-mode optical fiber, particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing cost.

Optical star coupler and method of manufacturing the same

An interface signal produces in a phase modulation type fiber optic gyroscope is classified into odd and even groups at a synchronous detector. An angular velocity is processed by the signals of even groups and odd groups.

Phase modulation type fiber optic gyroscope

An optical star coupler having a biconically tapered optical star coupler inserted and suspended in a protection tube and the method for manufacturing the same are disclosed. The manufacturing method provides that an optical fiber bundle is inserted into a protection tube such as hollow glass tube, then the optical fiber bundle is twisted and pulled while it is indirectly heated through the protection tube, thereby forming a twisting, fusing and pulling portion. Both ends of the protection tube are then sealed with an adhesive agent to fix the optical fiber bundle to the protection tube. This optical star coupler can be constructed so as to be connected in tandem without any splicing. The optical star coupler of the present invention, in the case of an optical star coupler using multi-mode optical fibers, and particularly in the case of one equally divided optical star coupler using single-mode optical fiber, also provides low insertion loss, less power deviation and low manufacturing costs.

Optical star coupler and method for manufacturing the same

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Katsuta, Japan

Hiroshi Araki