Yazaki Corporation

Takamitsu Aiba

Tomohiro Wakabayashi

Chiemi Yamagata

Hiroki Yasuda

Toshinori Suzuki

Kenji Shirasu

A transmission device includes an RF signal generation unit, a pulse signal generation unit, a coupling unit, a linear driver, and a light-emitting element. The RF signal generation unit generates an RF signal to be modulated by a carrier wave. The pulse signal generation unit generates a pulse signal. The coupling unit couples the RF signal and the pulse signal to each other and generate a superimposed signal. The linear driver amplifies the superimposed signal and generate an amplified signal. The light-emitting element converts the amplified signal to an optical signal and generate a superimposed optical signal. The pulse signal generation unit generates the pulse signal in such a way to satisfy fr=n×fs, where fr is a carrier wave frequency of the RF signal, fs is a first frequency being a reciprocal of a modulation speed of the pulse signal, and n is a natural number.

Transmission device and signal transmission system

An optical transmitter includes: a light emitting part that emits light; and a lens that condenses the light emitted from the light emitting part. Further, the optical transmitter includes a multimode optical fiber that is optically coupled to the lens at one end and on which the light that is condensed by the lens is incident. Furthermore, the coefficient of the correlation between the distribution of the intensity of the light in the light emitting part and the distribution of the intensity of return light to the light emitting part, when the light is emitted from the light emitting part, is set to 0.5 or less.

Optical transmitter and optical transmission system

Provided is a signal processor provided in a transceiver for transmitting and receiving a radio signal, and including a branch unit, a detection unit, a determination unit, and a power source controller. The branch unit branches a transmission signal and acquires a branch signal. The detection unit detects the branch signal and acquires a voltage value of the branch signal. The determination unit compares the voltage value of the branch signal with a threshold voltage previously stored in a storage unit and determines whether the voltage value of the branch signal is equal to or greater than the threshold voltage. The power source controller controls turning on and off of a power source for a reception signal amplifier of the transceiver according to a determination result determined by the determination unit.

Signal processor, RoF transceiver, fiber optic radio system, and signal processing method

A moving body-mounted communication system includes an internal connector, a third transmission line and a first information transmitting and receiving device. The internal connector is mounted in a moving body and connected to an external connector which is connected to a second transmission line. The third transmission line is arranged in the moving body and connected to the internal connector. The first information transmitting and receiving device is connected to the third transmission line. Information is transferred between a first transmission line used in an information and communication network outside the moving body and the second transmission line, and is transferred between the second transmission line and the third transmission line, without performing conversion of the information form of the information between light and electricity.

Moving body-mounted communication system and communication system

An optical fiber includes: a first core portion capable of transmitting first light; a second core portion formed on an outer periphery of the first core portion in a structure different from that of the first core portion and capable of transmitting second light different from the first light. The second core portion is formed around the outer periphery of the first core portion, and a center of the second core portion is positioned in a region of the first core portion.

Optical fiber and optical transmission module

A communication system includes a vehicle exterior antenna, an electro-optic converter, and a multimode optical fiber. The vehicle exterior antenna transmits and receives an electric signal to and from a cloud system in the exterior of a vehicle. The electro-optic converter is connected to the vehicle exterior antenna and converts an electric signal received by the vehicle exterior antenna into an optical signal. The multimode optical fiber has a plurality of propagation modes for propagation of optical signals and connects the electro-optic converter and an on-vehicle device (an opto-electric converter, an on-vehicle router, and the like) in the interior of the vehicle.

Growing community of inventors

Kanagawa, Japan

Takamitsu Aiba