Hitachi, Ltd.

Hitachi Media Electronics Co., Ltd.

Hitachi Metals, Ltd.

Kabushiki Kaisha Hitachi Seisakusho

Nihon Victor Kabushiki-kaisha

Takashi Shiba

Jun Yamada

Akitsuna Yuhara

Yuji Fujita

Yoshihiro Yamada

Toshimitsu Takahashi

Osamu Hikino

Yasuhiro Ohta

Kazuo Tsubouchi

Norio Hosaka

Yasuo Cho

Hiroyuki Nakase

Suguru Kameda

Yoji Isota

Katsumi Itoh

Takao Totsuka

Kensei Uehara

Kenji Hayashi

Hiroaki Ikeda

Migaku Takahashi

Keisuke Fukamachi

Makoto Katagishi

Hitoshi Yanagihara

Minoru Moteki

Toshiyuki Wada

Katsuya Yokoyama

Takemitsu Buma

Jyun Sasaki

Jyun Yamada

A piezoelectric thin-film acoustic wave device formed of a piezoelectric thin film of AlN on the +C plane and having the polarization strength of not lower than 0.63&#xd7;10F/V and an information processing unit using the same are disclosed. This is the result of the inventors having studied the factors other than the C-axis orientation affecting the electromechanical coupling factor and developing a method of improving the electromechanical coupling factor in view of the occasional fact that the electromechanical coupling factor cannot be improved by improving the C-axis orientation and the electromechanical coupling factor required for the piezoelectric thin-film acoustic wave device is not obtained. In such a case, the receiving sensitivity of the receiving system may be deteriorated and the transmission strength of the transmission system is required to be increased undesirably having an adverse effect on the power saving efforts.

Piezoelectric thin-film acoustic wave device and information processing unit using the same

A high-frequency circuit has a duplexer and a filter. The duplexer performs wave separation of send and received signals as input thereto. The filter filters the input send signal. When the send and received signals of the first modulation method are input, the send signal and the received signal of the first modulation method are wave-separated and output by the duplexer. When the received signal of the first modulation method is input, the send signal and the received signal of the first modulation method are wave-separated and output by the duplexer, and the send signal of the second modulation method is filtered by the filter.

High-frequency circuit apparatus and communication apparatus using the same

A multi-band transceiver has a function of sharing transmitted and received signals of multiple frequency bands by the same antenna. The multi-band transceiver mounts multiple filters that correspond to the multiple frequency bands and multiple amplifiers for amplifying the transmitted signals on the same substrate, and arranges the multiple filters in close vicinity to the amplifier in the order where the multiple filters are excellent in their temperature characteristic.

Multi-band transceiver and radio communication device using the transceiver

A structure of a spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc., and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.

Spread spectrum communication device and communication system

It is the object of the invention to provide a structure of a novel spectrum spreading communication device which solves the problem with the conventional spectrum spreading communication using Barker codes, etc. and limits the rise of the side-lobe of a correctional signal independently of the order of information codes by use of a code sequence having a code length of at least 14. The spectrum spreading communication device uses a pseudo-noise code having a code length of at least 14 and a self-correlation side-lobe of not greater than 3 as a pseudo-noise code of a direct spreading communication device which uses the pseudo-noise codes whose polarities are inverted so as to deal with also digital information. Thus, even when the pseudo-noise code length is 14 or more, the side-lobe of the correction coefficient can be restricted. Accordingly, the error rate of the spectrum spreading communication device is reduced and the processing gain is improved.

There is provided a surface acoustic wave device for use as a filter in a television receiver set which can reduce reflection waves generated from outermost electrodes of input and output interdigital transducers to improve various filter characteristics. In the surface acoustic wave device having, on a piezoelectric substrate, the input interdigital transducer for converting an electric signal into a surface acoustic wave and the output interdigital transducer, disposed to oppose the input interdigital transducer, for converting the surface acoustic wave resulting from the conversion by the input interdigital transducer into an electric signal, a first dummy electrode is provided to a first outermost electrode finger of the output interdigital transducer, the first outermost electrode finger being located at one end of the output interdigital transducer opposite to the input interdigital transducer, and having an electrode aperture length of .lambda./4 where n represents a wavelength of the surface acoustic wave, and a second dummy electrode is provided to a second outermost electrode finger of the input interdigital transducer, the second outermost electrode finger being located at one edge of the input interdigital transducer opposite to the output interdigital transducer, and having an electrode aperture length of .lambda./4.

Surface acoustic wave device

A surface acoustic wave device makes it possible to increase the electrode width without generating mass-electrical-loading and is capable of operating in a high-frequency band higher than or equal to the UHF band, and this surface acoustic way device may be used in a communication device to eliminate need for any down-converter which is indispensable to the conventional high-frequency communication device, and which is therefore capable of being manufactured at a reduced cost. The surface acoustic wave device is provided with an electrode structure meeting conditions represented by: s+m=(2n+1)L/(4k), where L is electrode period, not taking into consideration the polarity of an interdigital transducer, m is electrode line width, s is minimum electrode gap width, and n and k are natural numbers. The surface acoustic wave device is used as the demodulator of the communication device.

Surface acoustic wave device and communication device employing the

A method and apparatus for preparing thin films, a device, an electronic and magnetic apparatus, an information recording and reproducing apparatus, an information processing apparatus and a crystal preparing method from the molten state. A thin film is prepared as the substrate or the surface of the substrate is being excited and characterized by a device having at least a substrate and a thin film with at least one layer prepared thereon and an electronic and magnetic apparatus having integration of the devices, wherein at least one layer of the thin film is prepared as the surface of the substrate is being excited. The recording and reproducing apparatus for recording and reproducing information is composed of an information memory medium device having a recording layer of the thin film prepared as the surface of the substrate is being excited and a recording head whose core is prepared as the surface of the substrate is being excited. An information processing apparatus for use in input, record, process and output of information is composed of an information memory medium device having a recording layer which is prepared as the surface of the substrate is being excited and a processing part having a semiconductor device with a thin film prepared as the surface of the substrate is being excited.

Method and apparatus for preparing crystal thin films by using a surface

A surface acoustic wave device having a novel structure capable of restricting TTE and ripple noise on a frequency characteristics and group delay time characteristics thereof is provided under a condition by which acoustic reflection is suppressed when there is internal dissipation in the device and/or a peripheral circuit thereof. When the device includes a unidirectional interdigital transducer, it is possible to restrict ripple of the frequency characteristics and the group delay time characteristics and to reduce loss without using a phase shifter. By using the surface acoustic wave device according to the present invention, a communication apparatus can be improved in performance.

Surface acoustic wave device, equipment including the same with electric

In an interdigital electrode of a surface acoustic wave device having nonexciting portions formed by removing fingers, fingers having an excitation source located nearest to a nonexciting portion in between are so positioned as to approach the nonexciting portion as compared with arrangement pitch of other fingers. Fingers having an excitation source located nearest to an end of the electrode in between are so positioned as to approach the end of the interdigital electrode as compared with arrangement pitch of other fingers. Fingers having an excitation source located in the central portion of the electrode group in between are so positioned as to approach each other as compared with arrangement pitch of other fingers.

Surface acoustic wave device and communication device using the same

A surface acoustic wave apparatus wherein a reflector for reflecting a surface acoustic wave is provided on both sides of at least one of an input interdigital transducer and an output interdigital transducer, or, on one side of one of the input interdigital transducer and the output interdigital transducer.

Surface acoustic wave apparatus and method of productivity and

A surface acoustic wave device characterized in that in addition to linear first bus-bar electrodes which connect in alignment the edges of the same potential electrodes of interdigital electrodes, second bus-bar electrodes are provided which connect the same potential electrodes in the vicinity of the overlapping positions. Also disclosed is a surface acoustic wave device characterized in that the metalized ratio g/p, which is the ratio of the width of an electrode and the intercentral distance between the adjacent electrodes in an irregular pitch electrode group, is varied between 0.1 to 0.4 or between 0.6 to 0.9.

Growing community of inventors

Yokosuka, Japan

Takashi Shiba