Hitachi, Ltd.

Hitachi Automotive Systems, Ltd.

Masami Oonishi

Takashi Hirao

Takashi Yano

Kinya Nakatsu

Kenzaburo Fujishima

Rintaro Katayama

Eiichi Ide

Ryosuke Fujiwara

Junpei Kusukawa

Akihiro Namba

Kenichi Mizugaki

Yuichi Igarashi

Hiroki Yamada

The antenna apparatus has a base station installed in a first space partitioned by a wall, a radio terminal provided in a second space, and a repeater including passive antennas and installed on the wall. The repeater is constituted of a first antenna that transmits and receives signals to and from a base station, a plurality of second antennas that transmit and receive the signals to and from the radio terminal, and a transmission line that connects the first antenna with the second antenna. Further, the plurality of second antennas are installed such that planes of polarization of the second antennas are different from each other to improve transmission with the radio terminal.

Antenna apparatus

A computer system, which estimates a radio wave propagation characteristic in a space where a wireless communication system using structure data and system data is constructed, includes a computer having a processor and a storage apparatus and holds feature parameter information, which stores an entry that associates a parameter included in structure data, that is, a feature parameter which greatly contributes to an estimation result of the radio wave propagation characteristic in the space with a type of the space. When receiving a request for estimation of a radio wave propagation characteristic in a target space, the processor retrieves an entry associated with a type of the target space from the feature parameter information, and presents an interface to input a value of the feature parameter included in the retrieved entry as estimation structure data and an interface to input estimation system data.

Computer system, method for estimating radio wave propagation characteristic in space, and computer

A power conversion device includes first and second power semiconductor elements, and a circuit for transferring a drive signal of the first and second power semiconductor elements. The circuit board includes a first emitter wire which is formed along an arranging direction of the first power semiconductor element and the second power semiconductor element, a first gate wire which is disposed between the first power semiconductor element and the first emitter wire, a second gate wire which is disposed between the second power semiconductor element and the emitter wire, a third gate wire which is disposed to face the first gate wire and the second gate wire with the emitter wire interposed between the third gate wire and the first gate wire and the second gate wire, and a first gate resistor which connects the first gate wire and the third gate wire over the first emitter wire.

Power conversion device for reducing an inductance difference between control signal wires of a power semiconductor and suppressing a current unbalancing of the control signals

To improve yield and reliability at the time when a plurality of semiconductor elements used for a semiconductor device is arranged in parallel. A semiconductor device according to the present invention includes a first submodule which includes a first semiconductor element sandwiched between a first conductor and a second conductor and a first lead wire which transmits a control signal of the first semiconductor element, a second submodule which includes a second semiconductor element sandwiched between a third conductor and a fourth conductor and a second lead wire which transmits a control signal of the second semiconductor element, a fifth conductor which is formed to cover the first conductor and the third conductor and is bonded to the first conductor and the third conductor, and a sixth conductor which is formed to cover the second conductor and the fourth conductor and is bonded to the second conductor and the fourth conductor, in which the first conductor is formed so as not to overlap with a part of the first lead wire facing a first connection portion to be connected to the second lead wire.

Semiconductor device

An object of the present invention is to improve an antenna for IoT services intended for things that constitute an internal space. There is provided an antenna device including an antenna and a dielectric body. In an internal space which is constituted by plural faces including a first face which is an electrically conductive body, the antenna device is adapted to have a shape to be fit inside a hole in the first face. The antenna device is installed, not protruding from the hole to an outer space. The antenna and the dielectric body are placed in series between the internal space and the outer space.

Antenna device, manhole cover equipped with antenna device, and power distribution panel equipped with same

Growing community of inventors

Tokyo, Japan

Masami Oonishi