Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Masaharu Udagawa

Masaaki Niwa

Yoshihiko Hirai

Koichiro Yuki

Kenji Okada

Juro Yasui

Kiyoshi Morimoto

Hisashi Adachi

Toru Matsuura

Yasuaki Terui

Mamoru Arayashiki

Yoshihiro Hara

Kiyoyuki Morita

Taichi Ikedo

Juurou Yasui

Koyoshi Morimoto

The amplitude modulator comprises: an angle modulator for angle-modulating a phase signal to be inputted; a waveform shaping means in which, (1) when the magnitude of an amplitude signal to be inputted becomes smaller than a first prescribed value, a waveform of the amplitude signal is shaped so that the magnitude of the amplitude signal of the portion which becomes small becomes the first prescribed value; and/or (2) the waveform shaping means in which, when the magnitude of the amplitude signal to be inputted becomes larger than the second prescribed value which is larger than the first prescribed value, the waveform of the amplitude signal is shaped so that the magnitude of the amplitude signal of the portion which becomes larger becomes the second prescribed value; and an amplitude modulator for amplitude modulating the signal of the output of the angle modulator by the signal of the output of the waveform shaping means.

Modulation circuit device, modulation method and radio communication device

A transmission device having a preferable power efficiency and a wide control range of transmission output power. A pre-stage side of a high-frequency power amplifier changes an amplitude of a high-frequency phase modulation signal according to a base band amplitude modulation signal and a gain control signal. A variable gain amplifier changes the amplitude of the high-frequency phase modulation signal according to the base band amplitude modulation signal and the gain control signal, so that the base band amplitude modulation signal is supplied to an amplifier via a linear-log converter.

Transmission device and radio communication device

A transmitting apparatus includes a polar signal producing circuit which produces signals corresponding to the amplitude and the phase of a transmitting modulated wave from an input signal and multiplies the amplitude signal by the phase signal by a multiplying circuit to amplitude modulate a phase-modulated wave to produce a transmitting modulated wave and radiates this transmitting modulated wave as radio wave from an antenna. An amplitude/phase detecting circuit detects an amplitude signal and a phase signal from the input of the multiplying circuit and the input of a phase-modulated signal producing circuit. A delay difference computing circuit computes a correlation function between the amplitude signal produced by the polar signal producing circuit and the amplitude signal detected by the amplitude/phase detecting circuit and a correlation function between the phase signal produced by the polar signal producing means and the phase signal detected by the amplitude/phase detecting means, and computes a delay difference between the amplitude signal and the phase signal from maximum values of the respective correlation functions. Then, a timing adjusting circuit adjusts the delay time between the amplitude signal and the phase signal on the base of the computed delay difference.

Transmitter apparatus and method using polar modulation with signal timing adjustment

A polar modulation transmission apparatus is provided which can adjust synchronization between an amplitude signal and phase signal in a simple configuration accurately and automatically. A polar signal generation circuitsends an amplitude signal and phase signal for synchronization adjustment to transmission lines of these signals, incorporates the amplitude signal and phase signal for synchronization adjustment output from low pass filterswhich are final stage circuits that process the respective signals in their baseband signal states into a delay difference detection circuit, a synchronization adjustment control circuitobtains a synchronization adjustment value at which the delay difference between the signals is eliminated based on the delay difference detection result and a synchronization adjustment circuitgives delays corresponding to the synchronization adjustment value to the respective signals.

Polar modulation transmission apparatus and radio communication apparatus

By etching, a first groove and a second groove are formed in a silicon substrate. Surfaces of the side walls of these grooves have a surface orientation of (111). The first and second grooves sandwich a silicon thin plate therebetween, which is formed as a part of the silicon substrate. The silicon thin plate is sufficiently thin so as to act as a quantum well. Further, a pair of silicon oxide films acting as tunneling barriers are formed on the surfaces of the side walls of the silicon thin plate, thus forming a double barrier structure. In addition, a pair of polysilicon electrodes are formed and sandwich the double barrier structure. As a result, the structure of a resonance tunneling diode, which utilizes the resonance tunneling effect, is provided. Adding a third electrode to the above structure provides a resonance tunneling transistor.

Quantization functional device utilizing a resonance tunneling effect

A quantum device including a plate-like conductor part having a necking portion and a method of producing the same are disclosed. The method includes the steps of forming a first mask layer having a first strip portion on a conductor substrate; forming a second mask layer having a second strip portion on the conductor substrate; etching a region of the conductor substrate which is not covered with the first and second mask layers, by using the first and second mask layers as an etching mask, to form a plurality of first recess portions on a surface of the conductor substrate; selectively covering side faces of the plurality of first recess portions, and side faces of the first and second mask layers with a side wall film; selectively removing only the second mask layer, the first mask layer and the side wall film being left unremoved; etching another region of the conductor substrate which is not covered with the first mask layer and the side wall film, by using the first mask layer and the side wall film as an etching mask, to form a plurality of second recess portions on the surface of the conductor substrate; selectively removing part of another region of the surface of the conductor substrate which is not covered with the first mask layer and the side wall film; and removing the first mask layer and the side wall film, to form the plate-like conductor part having the necking portion at the conductor substrate.

Method of producing a quantum device which utilizes the quantum effect

A silicon substrate comprises at least two surfaces extending substantially along respective crystal faces of (111) crystal orientation of the silicon, the crystal faces of (111) crystal orientation crossing with each other, an electrically insulating layer formed by oxidizing the silicon substrate from the surfaces, and an electrically conductive portion insulated electrically by the electrically insulating layer from an outside of the silicon substrate.

Method of producing electrically insulated silicon structure

By etching, a first groove and a second groove are formed in a silicon substrate. Surfaces of the side walls of these grooves have a surface orientation of (111). The first and second grooves sandwich a silicon thin plate therebetween, which is formed as a part of the silicon substrate. The silicon thin plate is sufficiently thin so as to act as a quantum well. Further, a pair of silicon oxide films acting as tunneling barriers are formed on the surfaces of the side walls of the silicon thin plate, thus forming a double barrier structure. In addition, a pair of polysilicon electrodes are formed and sandwich the double barrier structure. As a result, the structure of a resonance tunneling diode, which utilizes the resonance tunneling effect, is provided. Adding a third electrode to the above structure provides a hot electron transistor. In the quantization functional devices having the above-described configuration, the satisfactory resonance effect is obtained due to a high crystallinity of the quantum well, a high potential barrier brought by the high quality silicon oxide films used as the tunneling barriers and a smooth interface between the quantum well and the tunneling barriers.

Method for producing quantization functional device utilizing a

For removing an unnecessary substance on a silicon substrate surface, a temperature of the unnecessary substance on the silicon substrate surface is not less than 750.degree. C. when the unnecessary substance is exposed to a gas including ozone.

Method for removing organic or inorganic contaminant from silicon

A quantum device including a plate-like conductor part having a necking portion made by forming a first mask layer having a first strip portion on a conductor substrate; forming a second mask layer having a second strip portion on the conductor substrate; etching a region of the conductor substrate which is not covered with the first and second mask layers, by using the first and second mask layers as an etching mask, to form a plurality of first recess portions on a surface of the conductor substrate; selectively covering side faces of the plurality of first recess portions, and side faces of the first and second mask layers with a side wall film; selectively removing only the second mask layer; etching another region of the conductor substrate which is not covered with the first mask layer and the side wall film, by using the first mask layer and the side wall film as an etching mask, to form a plurality of second recess portions on the surface of the conductor substrate; selectively removing part of another region of the surface of the conductor substrate which is not covered with the first mask layer and the side wall film; and removing the first mask layer and the side wall film, to form the plate-like conductor part having the necking portion.

Quantum device utilizing the quantum effect

A method is disclosed of forming semiconductor hetero interfaces that will contribute to the performance improvement of devices having semiconductor hetero interfaces such as MOS transistors, quantum devices, capacitors and the like. The method comprises the steps of making the surface of a semiconductor substrate clean and flat in terms of atomic level by heating said semiconductor substrate in vacuum to a temperature at which reconstruction of the surface atoms of said semiconductor substrate takes place, then forming a structural buffer layer such as a native oxide layer and the like on said semiconductor substrate surface after the temperature of said semiconductor substrate was lowered to room temperature and finally subjecting the semiconductor substrate with said structural buffer layer formed on its surface to a thermal treatment performed in certain specified temperature and atmosphere. Accordingly, the semiconductor substrate surface becomes smooth in terms of atomic level and an ultra smooth semiconductor interface is formed.

Method of forming semiconductor hetero interfaces

A silicon substrate comprises, at least two surfaces extending substantially along respective crystal faces of (111) crystal orientation of the silicon, the crystal faces of (111) crystal orientation crossing with each other, an electrically insulating layer formed by oxidizing the silicon substrate from the surfaces, and an electrically conductive portion insulated electrically by the electrically insulating layer from an outside of the silicon substrate.

Growing community of inventors

Tokyo, Japan

Masaharu Udagawa