scholarly journals High Frequency FM MEMS Accelerometer Using Piezoresistive Resonators

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1048
Author(s):  
Cláudia Coelho ◽  
João Gaspar ◽  
Luís A. Rocha
Keyword(s):  
Resonance Frequency ◽  
High Frequency ◽  
Output Signal ◽  
Bias Current ◽  
Q Factor ◽  
Device Layer ◽  
Mems Accelerometer ◽  
High Resonance Frequency ◽  
Double Mass ◽  
Soi Technology

A novel frequency modulated (FM) accelerometer based on piezoresistive resonators is presented. The accelerometer uses two differential resonators, connected to the accelerometer proofmass by an amplifying leverage mechanism. The piezoresistive double-mass resonators are electrostatically driven in anti-phase and the output signal is measured piezoresistively by applying a bias current to the connecting microbeam of the double-mass resonators. Accelerometers were fabricated using SOI technology with a 5 µm device layer. Fabricated resonators show a high resonance frequency around 705 kHz and a Q-factor close to 20,000 when measured in vacuum. Preliminary measurements show a sensitivity around 0.46 Hz/g for a single resonator.

Impact of High-Frequency Vibrations on Metal Items Resistance to Cyclic and Axial Loads

2018 ◽  
Vol 284 ◽  
pp. 587-592 ◽  
Author(s):  
I.R. Kuzeev ◽  
E.A. Naumkin ◽  
S.A. Pankratiev ◽  
R.R. Tlyasheva
Keyword(s):  
Fatigue Life ◽  
Resonance Frequency ◽  
Axial Compression ◽  
High Frequency ◽  
Forced Vibrations ◽  
Compression Force ◽  
Simultaneous Application ◽  
Resonance Frequencies ◽  
High Frequency Vibrations ◽  
Force Calculation

It was shown that the forced vibrations of objects on resonance frequencies could significantly change resistance of these objects to cyclic loads in a low-cycle loading range and decrease critical compression load under axial compression. We carried out a procedure of fatigue testing performance with simultaneous application of high-frequency vibrations. We developed and produced a device allowing carrying out testing aimed to check shape stability of cylindrical shells and their resistance to forced vibrations. Dependence of fatigue life capability within the low-cycle range on the frequency of applied forced vibrations in four harmonics of resonance frequency was experimentally determined. Fatigue life capability decreased by 1,6 times. Decrease of life capability particularly occurs on frequencies which are presumably connected with minimum in size elements of hierarchy of polycrystalline material structures. It was found out that the forced vibrations on resonance frequency contribute the increase of a number of vibrations, that leads to decrease of critical axial compression force value. Decrease can be by up to 40%. Experimental determination of critical load during application of vibrations allowed obtaining formula for adjusting factor calculation in the formula for permitted compression force calculation.

Design of Digital Controlled Signal Generator Based on DDS and MCU

2012 ◽  
Vol 468-471 ◽  
pp. 879-884
Author(s):  
Yin Jun Chen ◽  
Ze Huai Yuan
Keyword(s):  
High Frequency ◽  
Output Signal ◽  
Signal Generator ◽  
Signal Frequency ◽  
Program Execution

Its advantage to use DDS chip is output signal frequency bigger, and precision higher, But users can't change the output signal waveforms. The MCU can produce the required arbitrary waveforms, but its program execution of the order limit the speed.So we use their Synergy to design the digital controlled signal generator. The System has the advantage of output good quality waveform, frequency of precision and stability ,and high frequency, empty, amplitude and phase is to step into the need.

An ac method for the precise measurement of Q-factor and resonance frequency of a microwave cavity

2001 ◽  
Vol 72 (3) ◽  
pp. 1876 ◽  
Author(s):  
B. Nebendahl ◽  
D.-N. Peligrad ◽  
M. Požek ◽  
A. Dulčić ◽  
M. Mehring
Keyword(s):  
Resonance Frequency ◽  
Precise Measurement ◽  
Microwave Cavity ◽  
Q Factor

scholarly journals A time domain based method for the accurate measurement of Q-factor and resonance frequency of microwave resonators

2015 ◽  
Vol 86 (9) ◽  
pp. 094702 ◽  
Author(s):  
B. Gyüre ◽  
B. G. Márkus ◽  
B. Bernáth ◽  
F. Murányi ◽  
F. Simon
Keyword(s):  
Resonance Frequency ◽  
Time Domain ◽  
Q Factor ◽  
Microwave Resonators

Development of Sound Absorbers for Large Spaces

2005 ◽  
Vol 12 (4) ◽  
pp. 237-254
Author(s):  
Yoshihito Kobayashi ◽  
Toshiya Kitamura ◽  
Shinji Yamada
Keyword(s):  
Absorption Coefficient ◽  
Resonance Frequency ◽  
High Frequency ◽  
Sound Absorption ◽  
Low Frequency ◽  
Frequency Bands ◽  
Sound Fields ◽  
Absorption Area ◽  
Translucent Material ◽  
The Chairs

Moulded chairs have been developed, in which sound absorption at low frequency bands is increased by using the seat section and/or the back section as a resonator. In addition, a translucent sound absorption panel has been developed for application in large spaces. In the case of the chairs the resonance frequency, determined by the position, number, and depth of the holes, was examined. Prototypes were constructed, and the equivalent absorption area was measured in a reverberation room. The resonators of the chairs achieved an equivalent absorption area of 0.15 m2/seat, in the 125 Hz band. For the case of the translucent material, sound absorption was measured and compared with conventional sound absorption materials. The panels were designed in order to control sound fields in large spaces. The panels achieved a sound absorption coefficient of 0.6 to 1.0 at middle and high frequency bands.

Three Terminal HTc Vortex Flow Transistors: Optimisation of the Device Geometry Employing Bicrystal Grain-Boundary Josephson Junctions

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1253-1258
Author(s):  
V. Granata ◽  
B. A. Davidson ◽  
E. Sarnelli ◽  
S. Pagano
Keyword(s):  
High Temperature ◽  
Grain Boundary ◽  
Vortex Dynamics ◽  
High Frequency ◽  
Josephson Junctions ◽  
Vortex Flow ◽  
Operating Regime ◽  
Bias Current ◽  
Advantages And Disadvantages ◽  
Geometric Configurations

We have numerically studied the static and dynamic behavior of a three terminal vortex-flow transistor based on a parallel array of Josephson junctions. We explicitly show advantages and disadvantages for different device geometric configurations, systematically changing the symmetry of the bias-current distribution. Using parameters typical of high-temperature superconducting junctions at 77K, we have analysed for each configuration the dependence of the critical current on the control current, and the voltage-current curves. We have calculated gain and transresistance for different bias conditions, and explained the numerical results in terms of the vortex dynamics in the array. This study allows us to establish limits for the operating regime of these devices when used as high-frequency amplifiers.

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