Dual-frequency MEMS based Oscillator using a single ZnO-on-SOI Resonator

2015 ◽  
Vol 2015 (1) ◽  
pp. 000740-000744
Author(s):  
Di Lan ◽  
Julio Dewdney ◽  
I-Tsang Wu ◽  
Ivan Rivera ◽  
Adrian Avila ◽  
...  
Keyword(s):  
Wide Spectrum ◽  
Dual Frequency ◽  
Tank Circuit ◽  
Circuit Simulator ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Sinusoidal Waveform ◽  
Fundamental Oscillation ◽  
Stable Frequency ◽  
The Time Domain

In this paper, an oscillator technology with high-Q MEMS resonator as its tank circuit is presented to validate its key functionality as a stable frequency reference across a wide spectrum of frequencies. Particularly, a piezoelectrically-transduced contour-mode MEMS resonator is strategically designed to operate at two distinct layout-defined mechanical modal frequencies (259.5MHz and 436.7MHz). These devices were characterized and modeled by an extracted equivalent LCR circuit to facilitate the design of the oscillator using a standard circuit simulator. For this preliminary study, the MEMS resonators have been integrated with the sustaining amplifier circuit at PCB level using wire-bonding technique and coaxial connectors. As shown by the time-domain measurements, these oscillators are capable of selectively locking into the resonance frequency of the constituent MEMS resonator to generate a stable sinusoidal waveform with peak-to-peak amplitude of 4.6V at 259.5 MHz and 2.3V at 436.7 MHz, respectively. Meanwhile, the fundamental oscillation frequency and it harmonics can be easily observed in a measured frequency-domain spectrum.

Design of a MEMS Resonant Wind Sensor on Airplane Wing

2013 ◽  
Vol 562-565 ◽  
pp. 436-440
Author(s):  
Chao Wei Si ◽  
Guo Wei Han ◽  
Jin Ning ◽  
Wei Wei Zhong ◽  
Fu Hua Yang
Keyword(s):  
High Vacuum ◽  
Pressure Change ◽  
Wind Pressure ◽  
Damping Factor ◽  
Deep Reactive Ion Etching ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Element Simulation ◽  
Airplane Wing ◽  
Soi Substrates

A new kind of wind sensor made up of MEMS resonators is designed in the paper capable of sensing the lift, the resistance and the turbulence of airplane wings by mounting on the surface. The designed wind sensor is made up of four MEMS wind pressure gauges fixed around a square wind resistance block which used to block the wind to change the wind pressure on the surface, and the change of wind pressure is detected by MEMS wind pressure gauges to reveal the air condition on the surface of the airplane wings. As known, a MEMS resonator is a second-order resonant system whose damping factor is mainly dependent on the air pressure, and the characteristic is often used to detecting the airtightness of a sealed chamber for the damping factor is sensitive under high vacuum, while a MEMS resonator with the damping factor sensitive at atmospheric pressure is designed in this paper for sensing wind pressure change, and the MEMS resonator is manufactured on SOI substrates with deep reactive ion etching technology. Also relations between the wind pressure change and the wind speed around a block at atmosphere is revealed by finite element simulation. Compared to traditional wind sensors such as anemometers and Venturi tubes, the designed MEMS wind sensor with a very small size is suitable to mount on different zones of a wing with a large amount to monitor the air condition and have less influence on air flow.

ROM of Superharmonic Resonance of Second Order of Electrostatically Actuated MEMS Resonators

2015 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Christian Reyes
Keyword(s):  
Second Order ◽  
Voltage Response ◽  
Order Model ◽  
Reduced Order ◽  
Superharmonic Resonance ◽  
Electrostatically Actuated ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Method Effects ◽  
Ground Plate

This paper deals with the voltage-amplitude response (or voltage response) of superharmonic resonance of second order of MEMS resonator sensors under electrostatic actuation. The system consists of a MEMS flexible cantilever above a parallel ground plate. The AC frequency of actuation is near one fourth the natural frequency. The voltage response of the superharmonic resonance of second order of the structure is investigated using the Reduced Order Model (ROM) method. Effects of voltage and damping voltage response are reported.

Dynamic behaviours of the Double-end tuning fork based comb-driven microelectromechanical resonators for modulating the magnetic flux synchronously

2021 ◽  
Author(s):  
Zhenxi Liu ◽  
Jiamin Chen ◽  
Wuhao Yang ◽  
Tianyi Zheng ◽  
Qifeng Jiao ◽  
...  
Keyword(s):  
Detection Limit ◽  
Magnetic Flux ◽  
Resonance Frequency ◽  
Tuning Fork ◽  
Paper Making ◽  
Initial Space ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Mems Fabrication ◽  
First Time

Abstract MEMS resonators have been widely used in the magneto-resistive (MR) sensor for modulating the magnetic flux to enhance the detection limit. However, the manufacturing tolerances in MEMS fabrication processes make it challenging to fabricate the identical resonators with the same vibration frequency, which greatly decreases the detection limit of the MR sensor. To synchronize the MEMS resonators and improve the performance of the MR sensor, the double end tuning fork (DETF) based comb-driven MEMS resonators is proposed in this paper, making the system operate at the out-of-phase mode to complete the synchronization. The dynamic behaviour of the resonators is investigated through theoretical analysis, numerical solution based on MATLAB code and Simulink, and experimental verification. The results show that the transverse capacitances in the comb will significantly affect the resonance frequency due to the second-order electrostatic spring constant. It is the first time to observe the phenomenon that the resonant frequency increases with the increase of the bias, and it can also decrease with increasing the bias through adjusting the initial space between the fixed finger and the moving mass, they are different from the model about spring softening and spring hardening. Besides, the proposed DETF-based comb-driven resonators can suppress the in-phase and out-of-phase mode through adjusting the driving and sensing ports, and sensing method, meanwhile make the magnetic flux modulation fully synchronized, and maximize the modulation efficiency, and minimize the detection limit. These characteristics are appropriate for the MR sensor, even other devices that need to adjust the resonance frequency and vibration amplitude. Furthermore, the model and the design can also be extended to characteristic the single end tuning fork (SETF) based MEMS resonator and other MEMS-based MR sensors.

scholarly journals Testing Sensitivity of A-Type Residual Current Devices to Earth Fault Currents with Harmonics

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2044
Author(s):  
Stanislaw Czapp
Keyword(s):  
Power Systems ◽  
Electric Shock ◽  
Low Voltage ◽  
Wide Spectrum ◽  
Residual Current ◽  
Motor Speed ◽  
Earth Fault ◽  
Fault Currents ◽  
Wide Range ◽  
Sinusoidal Waveform

In many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in low-voltage power systems is commonly performed with the use of residual current devices (RCDs). In the presence of harmonics, the RCDs may have a tripping current significantly different from that provided for the nominal sinusoidal waveform. Thus, in some cases, protection against electric shock may not be effective. The aim of this paper is to present the result of a wide-range laboratory test of the sensitivity of A-type RCDs in the presence of harmonics. This test has shown that the behavior of RCDs in the presence of harmonics can be varied, including the cases in which the RCD does not react to the distorted earth fault current, as well as cases in which the sensitivity of the RCD is increased. The properties of the main elements of RCDs, including the current sensor, for high-frequency current components are discussed as well.

Controlling Crystallization Structures in Thin Si Film for Improving Characteristics of MEMS Resonators

2012 ◽  
Vol 1427 ◽  
Author(s):  
Shinya Kumagai ◽  
Hiromu Murase ◽  
Takashi Tomikawa ◽  
Syohei Ogawa ◽  
Ichiro Yamashita ◽  
...  
Keyword(s):  
Tensile Stress ◽  
Domain Size ◽  
Q Factor ◽  
Random Orientation ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Small Grains ◽  
Thin Polycrystalline ◽  
Lateral Crystallization ◽  
Conventional Annealing

ABSTRACTAn approach to control the tensile stress and Q factor of thin Si film beams in MEMS resonators was investigated. Metal-induced lateral crystallization (MILC) using Ni nanoparticles that were synthesized within a cage-shaped protein, apoferritin, was applied to a thin morphous Si film for making a MEMS resonator with thin film beams. The MILC produced a thin polycrystalline Si (poly-Si) film with large crystallized domain (50-60 μm) with nearly the same crystalline orientation, whereas the poly-Si film obtained by conventional annealing (without MILC) consisted of small grains (less than 1 μm) with random orientation. The MEMS resonator with a beam made of poly-Si film by MILC was fabricated. The large domain size and the improved crystallinity increased the tensile stress, and resulted in 20% increase in Q factor in the resonant characteristics.

Using Linear Superposition to Solve Multiple Heat Source Transient Thermal Problems

2007 ◽  
Author(s):  
David T. Billings ◽  
Roger P. Stout
Keyword(s):  
Heat Source ◽  
Transient Response ◽  
Response Curves ◽  
Linear Superposition ◽  
Circuit Simulator ◽  
Set Up ◽  
The Time Domain ◽  
The Individual ◽  
Transient Thermal ◽  
Application Engineer

For many years engineers have been using linear superposition to solve steady state thermal problems with multiple-heat-source systems. Predicting transient response of single-heat-source systems has been performed using R-C Foster networks with reasonable success. In most real applications there are multiple heat sources that are interacting perhaps in very complex ways in the time domain. Being able to simulate these interactions using a spreadsheet tool or a circuit simulator may be very advantageous to a device or application engineer designing or evaluating an application design. Using an RC-network model of a system to represent the individual transient response curves, we’ll show how to do this bookkeeping (and all the other calculations) for a simple system using Microsoft Excel. We’ll also see how to set up this sort of problem in a circuit simulator.

SELECTION OF A SUITABLE MODEL FOR QUANTITATIVE INTERPRETATION OF TOWED‐BIRD AEM MEASUREMENTS

Geophysics ◽  
1978 ◽  
Vol 43 (3) ◽  
pp. 576-587 ◽  
Author(s):  
G. J. Palacky
Keyword(s):  
Half Plane ◽  
Time Domain ◽  
Massive Sulfide ◽  
Suitable Model ◽  
Dual Frequency ◽  
Plane Model ◽  
Short Delay ◽  
Ore Bodies ◽  
Delay Times ◽  
The Time Domain

Many steeply dipping massive sulfide ore bodies have a dike‐like shape, and this has led to wide acceptance of the vertical half‐plane model in the interpretation of electromagnetic data. This model assumes that the conductor is thin, but the restriction has not been considered critical and in practice has frequently been disregarded. Conductance and conductor depth estimates based on the results of towed‐bird AEM surveys have been observed to be lower and less accurate than those obtained from helicopter EM and ground EM measurements. In order to explain the low reliability of the towed‐bird estimates, AEM responses over 17 Canadian ore bodies were analyzed. In the study, field results obtained by the time‐domain Input system and two dual‐frequency quadrature systems were interpreted. Error in conductance and depth estimates results from the frequency‐dependent, diffusive behavior of thick geologic conductors. This dependence makes invalid the basic assumption made in the interpretation of dual‐frequency quadrature EM data, that of the equivalence of response parameters at two frequencies. The estimated conductance and depth are too small when applying the current interpretation procedure based on amplitude ratios at two high and widely separated frequencies. The error is smaller in the case of Input time‐domain measurements, because the delay times are relatively long and the channels narrowly spaced. The vertical half‐plane model has been found to hold for ore bodies less than 10 m wide. In the case of wide mineralized zones, which are more important economically, the vertical half‐plane model could be successfully applied only at long delay times. Applying the vertical half‐plane nomogram at short delay times, the conductance and depth were underestimated, and better values could only be achieved by fitting the field data to a horizontal ribbon model. The consistently low conductance values interpreted from towed‐bird measurements for wide conductive zones have probably resulted in not selecting many potential massive sulfide targets for ground followup.

Voltage Response of MEMS Resonators Under Simultaneous Resonances

2014 ◽  
Author(s):  
Dumitru I. Caruntu ◽  
Christian Reyes
Keyword(s):  
Natural Frequency ◽  
Electrostatic Actuation ◽  
Voltage Response ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Simultaneous Resonances

This paper deals with MEMS resonator sensors under double electrostatic actuation. The system consists of a MEMS cantilever between two parallel fixed plates. The frequencies of actuation are AC near natural frequency, and AC half natural frequency. The voltage response of the structure is investigated, and parameter influences reported.

scholarly journals Evaluation of Residual Stress of C Oriented AlN/Si (111) and Its Impact on Mushroom Shaped Piezoelectric Resonator 

2021 ◽  
Author(s):  
AKHILESH PANDEY ◽  
Shankar Dutta ◽  
Nidhi Gupta ◽  
Davinder Kaur ◽  
R. Raman
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Mode Shapes ◽  
Quality Factors ◽  
Resonator Structure ◽  
Resonator Design ◽  
Mems Resonator ◽  
Mems Resonators ◽  
Quality Factor Q ◽  
Preferred Oriented

Abstract Aluminum nitride-based MEMS resonators are one of the interesting recent research topics for its tremendous potential in a wide variety of applications. This paper focuses on the detrimental effect of residual stress on the AlN based MEMS resonator design for acoustic applications. The residual stress in the sputtered c axis (<001>) preferred oriented AlN layers on Si (111) substrates are studied as a function of layer thickness. The films exhibited compressive residual stresses at different thickness values: -1050 MPa (700 nm), -500 MPa (900 nm), and -230 MPa (1200 nm). A mushroom-shaped AlN based piezoelectric MEMS resonator structure has been designed for the different AlN layer thicknesses. The effect of the residual stresses on the mode shapes, resonant frequencies, and quality factor (Q) of the resonator structures are studied. The resonant frequency of the structures are altered from 235 kHz, 280 kHz, and 344 kHz to 65 kHz, 75 kHz and 371 kHz due to the residual stress of -1050 MPa (thickness: 700 nm), -500 MPa (thickness: 900 nm) and -230 MPa (thickness: 1200 nm) respectively. At no residual stress, the quality factors of the resonator structures are 248, 227, 241 corresponding to the 700 nm, 900 nm, and 1200 nm thick AlN layers respectively. The presence of the residual stress reduced the Q values from 248 (thickness: 700 nm), 227 (thickness: 900 nm), 241 (thickness: 1200 nm) to 28, 53, and 261 respectively.

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