Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Hiroaki Seki

Shintaro Shinjo

Noriharu Suematsu

Akira Ohta

Kazutomi Mori

Akira Inoue

Kazunori Takahashi

Teruyuki Shimura

Kousei Maemura

Masaharu Hattori

Hiroomi Ueda

A high-power amplifier changes matching conditions of an output matching circuitconnected between a final stage amplifying elementand an output terminalin response to the output power of the amplifying element. Thus, the efficiency at low output power can be greatly improved without reducing the efficiency at the maximum output. Besides, since it is not necessary to load a DC-DC converter, an increase in size or cost can be prevented.

High-power amplifier

A high frequency amplifier includes a constant voltage driven amplifierusing as its amplifying element a bipolar transistorwith its base biased by a constant voltage, and a constant current driven amplifierusing as its amplifying element a bipolar transistorwith its base biased by a constant current. The idle current of the constant current driven amplifieris set at a low value. In accordance with the idle current, the idle current of the constant voltage driven amplifieris adjusted, and the two amplifiers are combined in parallel.

High-frequency amplifier

A frequency divider circuit including a field effect transistor on a semi-insulating substrate including applying a voltage higher than the lowest of the power supply voltages of the frequency divider circuit to the semi-insulating substrate.

Frequency divider having the power supply connected to the GaAs substrate

Growing community of inventors

Tokyo, Japan

Hiroaki Seki