Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Noriharu Suematsu

Tadashi Takagi

Yukio Ikeda

Shuji Urasaki

Shintaro Shinjo

Kazutomi Mori

Masayoshi Ono

Yoji Isota

Hiroyuki Joba

Gen Toyoshima

Kenichi Maeda

Hiroaki Nagano

Yoshitada Iyama

Kenji Itoh

Akinori Taira

Ryoji Hayashi

Mitsuhiro Shimozawa

Akira Ohta

Yoshihiko Konishi

Masataka Otsuka

Yasushi Sogabe

Eiji Taniguchi

Toshihisa Kamemaru

Takayuki Ikushima

Fumimasa Kitabayashi

Hiroaki Seki

Kouji Tsutsumi

Chiemi Sawaumi

Mitsuru Motizuki

Akira Inoue

Yoshinori Takahashi

Kazunori Takahashi

Yoshihiro Kashiba

Tatsuhiko Ikeda

Masao Yamawaki

Kenji Kawakami

Akio Iida

Takatoshi Katsura

Masaharu Hattori

Tadashi Kawahara

Hiroomi Ueda

Youji Isota

Masahiro Kamiyama

Mikio Uesugi

Kensuke Nakajima

Kenji Hiroshige

Katsuhisa Uno

When transmitting an RF signal for power supply or a pulse signal for data transmission, amplification is made in such a manner that the peak power of the RF signal becomes greater than the peak power of the pulse signal. Thus transmitting the RF signal with the greater peak power enables charging of a capacitorof noncontact wireless communication equipmenteven if the distance to the noncontact wireless communication equipmentis long.

Power supply apparatus and power supply method

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 converter includes a transistor pair having a first transistor and a second transistor respectively having collector terminals commonly connected to each other and emitter terminals commonly connected to each other, the commonly-connected collector terminals of the transistor pair being connected to a power supply terminal by way of a first resistor, a third transistor having a collector terminal connected to the power supply terminal by way of a second resistor and an emitter terminal connected to the commonly-connected emitter terminals of the transistor pair, a third resistor having an end connected to the commonly-connected emitter terminals of the transistor pair, and another end grounded by way of a constant current source, and an output terminal connected to the commonly-connected collector terminals of the transistor pair. The frequency converter can exhibit an excellent saturation characteristic and an excellent distortion characteristic even when operating from a low voltage and/or a low current.

Frequency converter

In a multi-layer substrate module receiving from an external earth node supply of a reference potential for grounding, a plurality of ground lines are provided respectively corresponding to a plurality of internal circuits. Moreover, a common node for coupling the ground lines is provided in an insulating layer of the multi-layer substrate module. The common node is electrically coupled to the earth node through a ground pin terminal shared by the plurality of internal circuits. Preferably, the common node is provided in the lowest insulating layer of the multi-layer substrate module. Thus, parasitic inductance of the portion through which an earth current flows, that is, the portion common to the plurality of internal circuits, can be suppressed with a small number of ground pin terminals. Accordingly, the inflow phenomenon of the earth current between the plurality of internal circuits is prevented, enabling stable operation.

Multilayer substrate module and portable wireless terminal

A high-frequency amplifying unitin which a steep gain variation developed according to a change in the amplitude of input high-frequency signal is suppressed is provided. It amplifies an input high-frequency signal with a plurality of transistors-to-N at the same time a measuring circuitmeasures amplitude of the input high-frequency signal, and a bias control circuitcontinuously controls a bias applied to each transistors-to-N according to the value of amplitude measured by the measuring circuit. Thus it is possible to suppress a steep gain variation produced according to a variation in the amplitude of input high-frequency signal.

A high frequency amplifier in which a common emitter bipolar transistor is used, and in that a constant current source and a constant voltage source are switched to apply a DC bias to a base terminal of the bipolar transistor in accordance with a power level of a high frequency signal input to the bipolar transistor or a power level of a high frequency signal output therefrom, and a frequency mixer in that a DC bias is applied to a base of at least one of a bipolar transistor for the input of a high frequency signal and a bipolar transistor for the input of a local oscillation wave by using a configuration for applying the DC bias to a base of an amplifying bipolar transistor employed in the high frequency amplifier.

High frequency amplifier and frequency mixer

A high-frequency amplifying unit in which a steep gain variation developed according to a change in the amplitude of input high-frequency signal is suppressed is provided. It amplifies an input high-frequency signal with a transistor at the same time a measuring circuit measures amplitude of the input high-frequency signal, and a bias control circuit continuously controls a bias applied to the transistor according to the value of amplitude measured by the measuring circuit . Thus it is possible to suppress a steep gain variation produced according to a variation in the amplitude of input high-frequency signal.

Semiconductor circuitry comprises a transistor pair (,) consists of a transistor having a base electrode to which a first signal is applied, and another transistor having a base electrode to which a signal having a phase opposite to that of the first signal is applied, the collector electrodes of those transistors being connected to each other and the emitter electrodes of the transistors being connected to each other, a third transistor (,) connected between a common emitter of the transistor pair and a ground potential and having a base electrode to which a second signal is applied, an output load (,) connected between a common collector of the transistor pair and a power supply (Vcc), and an output circuit for furnishing a third signal from the common collector of the transistor pair, thereby suppressing generation of any even-order higher harmonic of a local oscillation signal when the semiconductor circuitry operates from a low voltage.

Semiconductor circuitry

An operational command signal is output to one of an amplifier or a variable damper depending on the signal level of a high frequency signal.

Semiconductor circuit

An epitaxial layer is formed on a main surface of a high specific resistance silicon substrate having a specific resistance of at least 100 .OMEGA.cm. A circuit element such as an active element is formed in epitaxial layer. An oxide film is formed such that it covers a surface of epitaxial layer. A metal interconnection layer is formed on a surface of oxide film. An oxide film is formed such that it covers metal interconnection layer. Thus, an inexpensive HF circuit device capable of reducing transmission loss of HF signals can be obtained.

High-frequency circuit device and manufacturing method thereof

An unbalance-to-balance converter includes an FET and a balanced output adjusting capacitor connected between the source terminal of the FET and an earth conductor. The balanced output adjusting capacitor has a capacitance value equal to a capacitance difference Cpd-Cps between a drain side parasitic capacitance Cpd and a source side parasitic capacitance Cps. This makes it possible to solve a problem involved in a conventional unbalance-to-balance converter in that when the drain side parasitic capacitance Cpd differs from the source side parasitic capacitance Cps, a pair of balanced signals output from the drain terminal and source terminal do not have the same amplitude and are not in complete opposition.

Unbalance-to-balance converter utilizing a transistor

A radio frequency circuit is disclosed which includes a low-noise amplifier and a mixer integrated on the same semiconductor chip by using a silicon BiCMOS process. The low-noise amplifier has a silicon bipolar junction transistor and the mixer has a silicon MOS type field effect transistor. In the radio frequency circuit, the mixer can include two silicon MOS type field effect transistors one of which has a source connected to a drain of the other silicon MOS type field effect transistor and a gate of one silicon MOS type field effect transistor is supplied with a local signal and a gate of the other silicon MOS type field effect transistor is supplied with a radio frequency signal amplified by the low-noise amplifier.

Radio frequency circuit with integrated elements and method of

The detector comprises a first distributor for distributing a signal wave, a 45 degree shifter for shifting a local oscillation, a first even harmonic mixer and a second even harmonic mixer for generating a mixed wave between a double frequency wave of said local oscillation wave and said signal wave. The present invention can be used for increasing the accuracy and downsizing of quadrature mixer used in a receiving transmitting apparatus of a wireless communication system.

Detector and receiving and transmitting apparatus

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Tokyo, Japan

Noriharu Suematsu