Fujitsu Corporation

Yutaka Hirano

Masahiro Hayakawa

Kazuhiro Matsumoto

Akira Izumi

Nagahisa Furutani

Yoshikazu Dooi

Hideo Ashida

Hideki Ikuta

Nobutoshi Fukuden

Toshiaki Saito

Minoru Matsumoto

Takayuki Hasegawa

Masanobu Itoh

A selection unit, which is provided between an input matching unit and a high frequency amplification unit, is used to select a specific high frequency band to be amplified by the high frequency amplification unit from high frequency signals input from an input terminal. Further, an attenuation unit, which is provided between an input of the high frequency amplification unit and ground, is used to attenuate the input high frequency signals except for the specific high frequency band. Therefore, the specific high frequency band of the input high frequency signals is transferred from the input terminal to the high frequency amplification unit through the selection unit with a small loss, and the input high frequency signals except for the specific high frequency band are attenuated by the attenuation unit. Further, not only can stability of the high frequency amplification unit in the specific high frequency band used for the amplifier be realized, but stability of the high frequency amplification unit in other frequency bands except for the specific high frequency band can be also realized. Consequently, the high frequency amplifier does not oscillate and is not damaged.

High frequency amplifier having stable amplification operation

A semiconductor device comprising a conductive layer; an insulting layer mounted on the conductive layer and having an opening; terminals deposited on the insulating layer; an active semiconductor element mounted on the conductive layer or the insulating layer, and; a capacitor mounted on the conductive layer. In this device, a path between the semiconductor element and the capacitor is very short and the conductive layer serves as a heat sink.

RF transistor package with capacitor

Semiconductor device

A capacitor for use in microwave transistor, comprises a dielectric material layer and conductive layers covering both sides of the surfaces of the dielectric material layer. A plurality of points on the surface of one of the conductive layers are connected by conduction wires. Each of the conductive wires has a length less than .lambda..sub.0 /2.sqroot..epsilon..sub.r, where .lambda..sub.0 is the minimum wavelength of electric signals applied to the capacitor element, and .epsilon..sub.r is the dielectric constant of the dielectric material layer. The middle portion of each of the conductive lines is separated from the above-mentioned one of the conductive layers. The conductive wires prevent the capacitor element from becoming extremely inductive even when the frequency is high.

Capacitor element

A semiconductor device used, for example, for the amplification of microwave signals, comprising a plurality of semiconductor elements mounted on a base and connected parallel to each other in order to gain high output power, wherein the same type of corresponding electrodes of the adjacent semiconductor elements are directly connected to each other so that self oscillation does not occur in the device and the operation thereof is stable.

In a field effect transistor having interdigital electrodes the gate bonding pad portion is situated in the space formed between a pair of adjacent divided portions of the active region of the field effect transistor.

Field effect transistor

A high-power and high-frequency semiconductor device assembled on a base, comprising a semiconductor chip, capacitors for grounding high-frequency components, and capacitors for input impedance matching, the capacitors being arranged on a metal surface of the base.

Method of manufacturing a transistor which includes an emitter pattern and a base pattern and provides a predetermined current amplification factor, and said method includes a step of measuring a current amplification factor of a monitor transistor during the manufacturing process, the characteristic feature of said method includes the steps of forming a monitor transistor pattern providing the same amplification factor as the semi-conductor device to be manufactured, providing additional portions to an emitter pattern and a base pattern of said monitor transistor pattern, contacting a probe of the measuring apparatus to said additional portions and effecting the measurement of the amplification factor of the monitor transistor.

Growing community of inventors

Atsugi, Japan

Yutaka Hirano