River Eletec Corporation Ltd.

Nirasaki, Japan

River Eletec Corporation Ltd.

Nirasaki, Japan
SEARCH FILTERS
Time filter
Source Type

Sato T.,Yamanashi University | Marumo M.,River Eletec Corporation | Akitsu T.,Yamanashi University
IEEJ Journal of Industry Applications | Year: 2017

In this study, we studied Lamb wave resonator driver circuit with inductive compensation of the internal capacitance to improve the frequency limit by the transition frequency fT which is one of the important parameters of active components for deciding amplification and oscillation. Comparing with an SAW resonator, the Lamb-wave oscillator can provide highly stable frequency-temperature characteristics and smaller frequency deviation at the normal temperature. The inductive cancellation scheme of the internal capacitor of the CMOS inverter realizes oscillation over fT. © 2017 The Institute of Electrical Engineers of Japan.


Satoh T.,Yamanashi University | Izyan Ruslan R.,Yamanashi University | Katou Y.,Yamanashi University | Marumo M.,River Eletec Corporation Ltd. | Akitsu T.,Yamanashi University
IEEJ Transactions on Electrical and Electronic Engineering | Year: 2011

Novel circuit design is proposed for a low-frequency quartz crystal oscillator circuit that consists of four segments. The characteristics of the negative resistance in a low-frequency Complementary Metal Oxide Semiconductor (CMOS)-inverter quartz oscillator were reviewed for the two modes of SC (stress-compensated) cut mode and the overtone of low-frequency mode; separation of two modes and suppression of overtone oscillation were demonstrated successfully. Experimental results and an estimate of the absolute value of the negative resistance are presented for the four-segment oscillator circuit and the conventional Colpitts circuit and two new types of oscillator circuits. © 2011 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.


Satoh T.,Yamanashi University | Izyan Ruslan R.,Yamanashi University | Itoh K.,Yamanashi University | Marumo M.,River Eletec Corporation Ltd. | Akitsu T.,Yamanashi University
IEEJ Transactions on Electrical and Electronic Engineering | Year: 2011

Novel circuit design is proposed for low-frequency quartz crystal oscillator circuit with the enhanced control of excitation level. The function of the limiter circuit was analyzed on the base of the negative resistance of the CMOS-inverter quartz oscillator reviewed for the fundamental mode of a quartz crystal microbalance resonator, and appropriate gain control and drive current reduction were realized by adding a capacitor between one terminal of the quartz crystal and the ground level. Experimental result and the absolute value of the negative resistance are compared with the conventional Colpitts circuit. © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. © 2010 Institute of Electrical Engineers of Japan.


Satoh T.,Yamanashi University | Izyan Binti Ruslan R.,Yamanashi University | Marumo M.,River Eletec Corporation Ltd. | Akitsu T.,Yamanashi University
IEEJ Transactions on Electrical and Electronic Engineering | Year: 2012

A novel design is proposed for a low-frequency quartz crystal oscillator circuit. Negative resistance in a low-frequency CMOS-inverter quartz oscillator was reviewed for the fundamental mode at 32 kHz and the overtone oscillation at 200 kHz. Suppression of the overtone oscillation, appropriate gain, and drive current reduction are realized by adding only three circuit components. Experimental results and an estimate of the absolute value of the negative resistance are presented for the conventional Colpitts circuit and two types of the quartz crystal oscillator circuit. © 2011 Institute of Electrical Engineers of Japan.


Takano A.,Tokyo Denki University | Kon T.,Rivereletec Co. | Furuya Y.,Hirosaki University | Mochitate K.,Japan National Institute of Environmental Studies | And 2 more authors.
2013 International Symposium on Micro-NanoMechatronics and Human Science, MHS 2013 | Year: 2013

We have developed a poly(dimethylsiloxane) (PDMS)-made microfluidic long-term cell culture platform having two cell culture wells with piezoelectric substrate bottom on which shear horizontal surface acoustic wave (SH-SAW) propagates. The SH-SAW propagates on the cells could be used to assay cell-cell and/or cell-surface interaction. The platform also enables optical observation of the cells and acquisition of SH-SAW signals simultaneously. The combination of the on-chip CO2 incubation and SH-SAW-based cell monitoring system successfully detected a long-term change in cell-cell or cell-substrate interaction induced by hydrogen peroxide (H2O2). © 2013 IEEE.


Higashiyama T.,Hirosaki University | Katsuyama A.,Hirosaki University | Otori H.,Hirosaki University | Kamimura T.,Hirosaki University | And 9 more authors.
Ultrasonics | Year: 2014

The rat lung epithelial cell line SV40-T2 was used to develop a cellular biosensing system to assay for environmental toxicants. The novel approach on which this system is based involves direct attachment of cultured rat or human cells onto a cell-adhesive matrix on the device through which shear horizontal surface acoustic waves (SH-SAW) are transmitted using 50 MHz SAW resonator. This novel design enables sensitive monitoring of changes of the electrophysical characteristics of cells, such as their conductivity and relative permittivity. A time-dependent change of phase of SAW and change of insertion loss (change of amplitude) were observed when the cells were treated with 0.5 or 1.0 mM H 2O2. The change of insertion loss was biphasic, with an early phase (1-3 h) and a late phase (3-6 h). The late phase coincided with the destruction of cell-cell tight junctions detected by measurement of the transepithelial electrical resistance and paracellular permeability; in contrast, the early phase coincided with the destruction of intracellular actin filaments by H2O2. The early-phase effect of H 2O2 on phase shift may be attributable to the change of intracellular permittivity by a change of cellular polarity. Immunofluorescence microscopy showed the disappearance of zonula occludens protein 1 from the region of cell-cell contact. These results suggest the correlation between the change of insertion loss as an SAW parameter and the destruction of tight junctions of the cells on the SH-SAW device in the late phase. © 2014 Elsevier B.V. All rights reserved.


Otori H.,Hirosaki University | Higashiyama T.,Hirosaki University | Uehara A.,Chiyoda Corporation | Kainuma M.,Hirosaki University | And 6 more authors.
Sensors and Actuators, A: Physical | Year: 2013

We developed a cellular biosensing system based on the direct assembly of rat- or human-cultured cells onto a shear horizontal-surface acoustic wave (SH-SAW) device. This novel design enables the sensitive monitoring of changes in physical cell-characteristics, such as viscosity or density inside the cells. In our system, the change of phase of SAW and insertion loss was observed to be time-dependent when the rat lung epithelial cells were treated with 1.0mM H2O2. Immunofluorescence microscopy showed the disappearance of the zonula occludens protein from the cell-cell contact region. Furthermore, the transepithelial electrical resistance of the cells gradually decreased owing to this treatment. These results suggest the correlation between the change of SH-SAW phase, the insertion loss of the SH-SAW parameter, and the destruction of the tight junction of the cells on SH-SAW devices. Crown Copyright © 2012 Published by Elsevier B.V. All rights reserved.


Yamagata Y.,River Eletec Corporation | Mizumoto K.,River Eletec Corporation
IFCS 2014 - 2014 IEEE International Frequency Control Symposium, Proceedings | Year: 2014

This paper describes a new shape miniature GT cut quartz resonator vibrating at 12 MHz and in a (m = 3, n = 1) mode. A relationship between a dimensional ratio (w/l) and a cutting angle YXlt (θ)/(45°) of the new shape GT cut quartz resonator with first and second order temperature coefficients α ≒ 0 and β ≒ 0 is clarified by FEM (Finite Element Method). Namely, the analysis results show α and β become almost 0, when the dimensional ratio (w/l) is 0.96 and the cutting angle is YXlt (θ = 47°)/(45°). It is confirmed by experiments that the new shape miniature GT cut quartz resonator has a frequency deviation of ±5 ppm in a wide temperature range of -30 °C to +90 °C with a small series resistance R1 of 98 Ω and a quality factor Q of 58000. © 2014 IEEE.


Patent
River Eletec Corporation | Date: 2016-05-04

[Object] To provide an elastic wave device that has an phase velocity optimum for a high-frequency oscillation as well as a preferred frequency temperature behavior that exhibits a cubic curve by utilizing a rotated Y-cut quartz crystal substrate with novel Euler angles of rotation. [Means of Realizing the Object] An elastic wave device 11 includes a quartz crystal substrate 12 and at least one excitation-electrode 13. The quartz crystal substrate 12 is cut out from a quartz crystal body that has three-dimensional crystallite orientation composed of an X-axis, a Y-axis, and a Z-axis with both the Y-axis and the Z-axis rotated around the X-axis. The quartz crystal substrate 12 is cut at rotation angles specified by right-handed Euler-angles (, , ). The at least one excitation-electrode 13 generates a plurality of plate waves on a front surface of the quartz crystal substrate 12. The quartz crystal substrate 12 is cut at rotation angles in the range of = 0 10, = 110 to 140, = 30 to 50. The selected vibration mode of the quartz crystal substrate 12 is a plate wave that has a primary temperature coefficient 10^(-6) in the range of -1.0 < < +1.0 and a secondary temperature coefficient 10^(-8) in the range of -1.0 < < +1.0 with Taylor expansion performed at 25C.


Patent
River Eletec Corporation | Date: 2014-06-26

An elastic wave device is provided that has an phase velocity optimum for a high-frequency oscillation as well as a preferred frequency temperature behavior that exhibits a cubic curve by utilizing a rotated Y-cut quartz crystal substrate with novel Euler angles of rotation. The elastic wave device includes a quartz crystal substrate and an excitation-electrode. The quartz crystal substrate is cut out from a quartz crystal body that has a particular three-dimensional crystallite orientation. The quartz crystal substrate is cut at rotation angles specified by right-handed Euler-angles. The excitation-electrode generates a plurality of plate waves on a front surface of the quartz crystal substrate. The quartz crystal substrate is cut at rotation angles in a given range. The selected vibration mode of the quartz crystal substrate is a plate wave having a primary and a secondary temperature coefficient in given ranges with Taylor expansion performed at a particular temperature.

Loading River Eletec Corporation Ltd. collaborators
Loading River Eletec Corporation Ltd. collaborators