scholarly journals A Study on the Trimming Effects on the Quality Factor of Micro-Shell Resonators Vibrating in Wineglass Modes

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 695
Author(s):  
Lu ◽  
Xi ◽  
Xiao ◽  
Shi ◽  
Zhuo ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Quality Factor ◽  
Second Harmonic ◽  
Great Influence ◽  
Fem Simulation ◽  
Q Factor ◽  
Thermoelastic Damping ◽  
Frequency Trimming ◽  
Quality Factor Q ◽  
Anchor Loss

Frequency trimming based on mass and stiffness modification is an important post-fabrication process for micro-shell resonators (MSRs). However, the trimming effects on the quality factor are seldom studied, although they may have great influence on the performance of the resonator. This paper presents a study on the quality factor (Q-factor) variation of trimmed micro-shell resonators (MSR). Thermoelastic damping (QTED) and anchor loss (Qanchor) are found to be the dominant energy loss mechanisms resulting in the reduction of the overall Q-factor, according to finite element method (FEM). The effects of different trimming methods on QTED and Qanchor are studied here, respectively. It is found that trimming grooves ablated in the rim of the resonator can cause a ~1–10% reduction of QTED, and the length of trimming groove is positively related to the reduction of QTED. The reduction of QTED caused by the mass adding process is mainly related to the thermal expansion coefficient and density of the additive and contact area between the resonator and additive masses. Besides, the first and second harmonic errors caused by asymmetrical trimming can cause a 10–90% reduction of Qanchor. Finally, trimming experiments were conducted on different resonators and the results were compared with FEM simulation. The work presented in this paper could help to optimize the trimming process of MSRs.

Investigation of the Measured Quality Factor Versus Polarization Voltage of a Multiple-Beam Tuning-Fork Gyroscope

2012 ◽  
Author(s):  
Peng Cheng ◽  
Yujie Zhang ◽  
Wenting Gu ◽  
Zhili Hao
Keyword(s):  
Quality Factor ◽  
Tuning Fork ◽  
Factor Versus ◽  
Mechanical Quality Factor ◽  
Thermoelastic Damping ◽  
Polarization Voltage ◽  
Multiple Beam ◽  
Mechanical Quality ◽  
Quality Factor Q ◽  
Anchor Loss

In light of the importance of the mechanical Quality factor (Q) to the ultimate performance of tuning-fork gyroscopes, this paper presents an investigation on the effect of polarization voltage on the Q of a multiple-beam tuning-fork gyroscope. An experimental study is conducted to quantify the relation of the measured Q of the gyroscope to polarization voltage. The two loss mechanisms, thermoelastic damping and anchor loss, in the device are analyzed to identify the reason behind the Q drop with polarization voltage. Using a numerical model of thermoelastic damping built upon thermal-energy method, polarization voltage is found to have a negligible effect on the Q of the gyroscope. Due to the asymmetry of the fabricated devices resulting from fabrication variations, anchor loss is identified as the cause of the Q drop with polarization voltage and an analytical model of anchor loss is further proposed to take polarization voltage into account.

Effect of Geometric Imperfections on Anchor Loss and Characterisation of a Gyroscope Resonator with High Quality Factor

2020 ◽  
Vol 28 (3) ◽  
pp. 18-31
Author(s):  
G.N. Sharma ◽  
◽  
Sundararajan T. ◽  
G.S. Singh ◽  
◽  
...  
Keyword(s):  
Quality Factor ◽  
Shell Thickness ◽  
Sensitivity Study ◽  
Thickness Variation ◽  
Q Factor ◽  
Surface Characterisation ◽  
Geometric Imperfections ◽  
Before And After ◽  
Functional Part ◽  
Anchor Loss

A critical functional part of a hemispherical resonator gyroscope (HRG) is the mechanical resonator, and a few million quality factor (Q-factor) is needed for the lowest resolution. This paper focuses on anchor loss of a HRG of a few millimeters in size. A detailed parametric study of dimensions and shell imperfections due to fabrication is carried out. A sensitivity study of the effect of shell mean radius, shell thickness, stem radius, stem height on the Qanchor is carried out. The effect of geometric imperfections such as shell offset, shell tilt, shell thickness variation, and unbalance is studied in detail. From the study, it is inferred that the anchor loss becomes very significant and approaches other loss mechanisms even with minor geometric imperfections in the hardware realisation. Based on the sensitivity study, the dimensional and geometric tolerances are arrived for precision fabrication. Precision resonator is fabricated as per the requirement of minimum anchor loss. The significance of other damping mechanisms such as air damping, excitationinduced damping, thermoelastic dynamic damping and surface dissipation is also discussed. Surface characterisation before and after surface treatment has been carried out using nanoindentation technique with regard to surface loss. Functional parameters of operating frequency and Q-factor are evaluated using laser Doppler vibrometry (LDV).

Performance Investigate and Analysis of 96 × 10 Gbps DWDM System Using Suitable Rating from Optical Amplifiers

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Chakresh Kumar ◽  
Ghanendra Kumar
Keyword(s):  
Quality Factor ◽  
Fiber Length ◽  
Optical Amplifiers ◽  
The Other ◽  
Superior Performance ◽  
Q Factor ◽  
Probability Of Error ◽  
Raman Amplifier ◽  
Quality Factor Q ◽  
Dwdm System

AbstractThe objective of current work is to design and analyzed 96×10 Gbps DWDM system taking EDFA, SOA, and RAMAN amplifier as an inline amplifiers up to a fiber length of 300 km. The performance of EDFA, SOA, and RAMAN amplifier is measured on the basis of power received, Q-factor, probability of error and BER for various values of fiber distance. In this paper it has been proved that for 96 channels DWDM system at 10 Gbps bit rate, EDFA reveals superior performance as far as the amount of power received is concerned. The value of quality factor (Q-factor) for RAMAN amplifier is almost identical to that of the Q-factor for EDFA and is higher than the Q-factor for SOA till a fiber length of roughly 80 km thereafter SOA reveals somewhat better Q-factor than EDFA and RAMAN amplifier. As far as BER is concerned EDFA and RAMAN amplifier show roughly identical and somewhat lower BER than SOA till a fiber length of roughly 80 km, afterwards SOA reveal somewhat lesser BER till the fiber length of 210 km. In relation to the probability of error P(E), It is analyzed that P(E) remains more or less same for the entire set of optical amplifiers(OAs) but beyond the fiber length of 240 km EDFA shows somewhat lower P(E) than the other two OAs. At the end the Eye diagrams for the three OAs are also figure out.

Design to Operational Parameters Dependency on Quality Factor of Sensor Mechanical Resonators

2021 ◽  
Vol 29 (2) ◽  
pp. 3-34
Author(s):  
G.N. Sharma ◽  
◽  
Sundararajan T. ◽  
G.S. Singh ◽  
◽  
...  
Keyword(s):  
Internal Friction ◽  
Quality Factor ◽  
Ring Resonators ◽  
Future Research ◽  
Operating Pressure ◽  
Q Factor ◽  
Operational Parameters ◽  
Mechanical Resonator ◽  
Macro Scale ◽  
Anchor Loss

The critical functional part of any high performance resonance based sensor is a mechanical resonator. The performance is measured by resonator quality factor (Q-factor). Damping mechanisms such as thermoelastic damping (TED), anchor loss, surface loss, material internal friction, fluid damping and electronics damping are covered in this review with more focus on gyroscope resonators. Dissipations can be reduced by different means. Hence, the effects of various design to operational parameters on the Q-factor for different configurations, sizes and materials are reviewed in detail. Micro scale ring resonators can achieve a Q-factor of the order of hundreds of thousands. Macro scale hemispherical resonators are suitable for ultrahigh Q-factors. High temperature sensor operation is not preferred because of TED, while sub-zero operation is limited by material internal friction. Few orders of dissipation increase are seen with thin film metallic coating due to TED and coating material internal friction. High precision fabrication is mandatory to achieve the designed minimum anchor loss as it is highly sensitive to fabrication imperfections. Q-factor sensitivity to operating pressure is different for different resonator configurations. This review study helps to build a comprehensive mechanical resonator design, realization and operation strategy to achieve high sensor performance. A roadmap on future research requirements for developing compact mass producible CVG type sensors with ultrahigh Q-factor is also highlighted.

Thermoelastic Damping Based Design, Sensitivity Study and Demonstration of a Functional Hybrid Gyroscope Resonator for High Quality Factor

2021 ◽  
Vol 29 (1) ◽  
pp. 70-96
Author(s):  
N.G. Sharma ◽  
◽  
Sundararajan T. ◽  
G.S. Singh ◽  
◽  
...  
Keyword(s):  
Thin Film ◽  
Quality Factor ◽  
Sensitivity Study ◽  
Fused Silica ◽  
High Quality Factor ◽  
Q Factor ◽  
Thermoelastic Damping ◽  
High Quality ◽  
Field Problem ◽  
Macro Scale

The most critical element of Hemispherical Resonator Gyroscope (HRG) is the high quality factor (Q-factor) mechanical resonator. This paper discusses the role of thermoelastic damping (TED) on effective Q-factor. Finite element method (FEM) is used to solve this highly coupled field problem involving vibration, solid mechanics, heat transfer and thermodynamics. The major contribution of this paper is the sensitivity analysis of the effect of material property, operating temperature and dimensions to arrive at macro scale resonator configuration. Hybrid hemispherical-cylindrical configuration is proposed by studying the performance parameters such as effective mass and angular gain.The uniqueness of the present work is the sensitivity study of ultra thin film coating (volume fraction of 0.01%), coating variations and different coating configurations. The coating can reduce the Q-factor by a few orders compared to uncoated shell. It has been found that coating material selection and coating configuration are very important factors. Another significance of the present work is the realization and detailed characterization of the hybrid fused silica resonator. Thin film gold coating is done on the 3D surfaces of the realized precision resonator. Detailed coating characterization is carried out using sophisticated instruments. Very fine balancing to the order of a few mHz is achieved after coating. Q-factor measurement of the coated resonator is carried out using LDV and achieved a few millions in the final functional hybrid resonator.

High Quality Factor using Nested Complementary Split Ring Resonator for Dielectric Properties of Solids Sample

2020 ◽  
Vol 35 (10) ◽  
pp. 1222-1227
Author(s):  
Norhanani Rahman ◽  
Zahriladha Zakaria ◽  
Rosemizi Rahim ◽  
Maizatul Said ◽  
Amyrul Bahar ◽  
...  
Keyword(s):  
Quality Factor ◽  
Error Detection ◽  
Ring Resonator ◽  
Split Ring Resonator ◽  
Q Factor ◽  
Split Ring ◽  
Theoretical Simulation ◽  
Complementary Split Ring Resonator ◽  
Industry Applications ◽  
Quality Factor Q

A Nested complementary split ring resonator (CSRR) was proposed based on planar structure. The main objective of this work is to get a higher quality factor (Q-factor) with minimal error detection of complex permittivity. The sensor operated at the 3.37GHz resonant frequency and simulated by ANSYS HFSS software. Subsequently, the designed sensor has been fabricated and tested with the presence of several material under test (MUTs) placed over the sensor. The result achieved high unloaded Q-factor, 464. There has been proof of good agreement concerning the results between theoretical, simulation, and measured parameters of error detection, which is below 13.2% real part permittivity and 2.3% the loss tangent. The proposed sensor is practically useful for the food industry, bio-sensing, and pharmacy industry applications.

Effect of Geometric and Material Properties on Thermoelastic Damping (TED) of 3D Hemispherical Inertial Resonator

2016 ◽  
Author(s):  
Jiewen Liu ◽  
Joshua Jaekel ◽  
Dharamdeo Ramdani ◽  
Nabeel Khan ◽  
David S.-K. Ting ◽  
...  
Keyword(s):  
Material Properties ◽  
Design Parameters ◽  
Q Factor ◽  
Thermoelastic Damping ◽  
High Quality ◽  
Hemispherical Shell ◽  
Edge Defects ◽  
Wine Glass ◽  
Quality Factor Q ◽  
Crucial Parameter

High quality factor (Q-factor) is a crucial parameter for the development of precision inertial resonators. Q-factor indicates efficiency of a resonator in retaining its energy during oscillations. This paper explores the effects of different design parameters on Q-factor of a 3D hemispherical (wine-glass) inertial resonator. Thermo-elastic damping (TED) loss mechanisms in a 3D non-inverted wine-glass (hemispherical) shell resonator is systematically investigated and presented in this paper. We investigated TED loss resulting from the effects of hemisphere geometric parameters (such as thickness, height, and radius), mass imbalance, thickness non-uniformity, and edge defects. We used glassblowing to fabricate hemispherical 3D shell resonators. The results presented in this paper can facilitate selecting efficient geometric and material properties for achieving desired Q-factor in 3D inertial resonators. Enhancing the Q-factor in MEMS based 3D resonators can further enable the development of high precision resonators and gyroscopes.

scholarly journals 5G planar branch line coupler design based on the analysis of dielectric constant, loss tangent and quality factor at high frequency

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Nor Azimah Mohd Shukor ◽  
Norhudah Seman
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Quality Factor ◽  
Loss Tangent ◽  
High Frequency ◽  
Q Factor ◽  
Bandwidth Enhancement ◽  
Branch Line ◽  
Fifth Generation ◽  
Quality Factor Q

Abstract This study focuses on the effect of different dielectric properties in the design of 3-dB planar branch line coupler (BLC) using RT5880, RO4350, TMM4 and RT6010, particularly at high frequency of 26 GHz, the fifth generation (5G) operating frequency. The analysis conducted in this study is based on the dielectric constant, loss tangent and quality factor (Q-factor) associated with the dielectric properties of the substrate materials. Accordingly, the substrate that displayed the best performance for high frequency application had the lowest dielectric constant, lowest loss tangent and highest Q-factor (i.e., RT5880), and it was chosen to enhance our proposed 3-dB BLC. This enhanced 3-dB BLC was designed with the inclusion of microstrip-slot stub impedance at each port for bandwidth enhancement, and the proposed prototype had dimensions of 29.9 mm × 19.9 mm. The design and analysis of the proposed 3-dB BLC were accomplished by employing CST Microwave Studio. The performance of scattering parameters and the phase difference of the proposed BLC were then assessed and verified through laboratory measurement.

scholarly journals Electromagnetic Radiation from a Tesla Transformer

2017 ◽  
Vol 9 (2) ◽  
pp. 53
Author(s):  
R M Craven ◽  
I R Smith ◽  
B M Novac
Keyword(s):  
Electromagnetic Radiation ◽  
Quality Factor ◽  
Dielectric Losses ◽  
Far Field ◽  
Q Factor ◽  
Power Losses ◽  
Tesla Transformer ◽  
Power Transfer Efficiency ◽  
Quality Factor Q ◽  
Secondary Winding

In addition to the resistive and dielectric losses that inevitably occur near the secondary winding of a Tesla transformer, electromagnetic radiation into the far field also contributes to the overall power losses and thereby reduces both the effective quality factor (Q) and the power transfer efficiency of this winding. A short study of these effects for a laboratory scale transformer has shown that, in addition to its Q-factor being considerably reduced, the secondary winding is an extremely inefficient radiator of electromagnetic energy.

scholarly journals Sound Trapping in an Open Resonator

2021 ◽  
Author(s):  
Lujun Huang ◽  
Yan Kei Chiang ◽  
Sibo Huang ◽  
Chen Shen ◽  
Fu Deng ◽  
...  
Keyword(s):  
Quality Factor ◽  
Mirror Symmetry ◽  
Bound States ◽  
Open Resonator ◽  
Acoustic Resonator ◽  
Q Factor ◽  
Order Of Magnitude ◽  
Symmetry Protected ◽  
Quality Factor Q ◽  
Mode Interference

Abstract The ability of extreme sound energy confinement with high-quality factor (Q-factor) resonance is of vital importance for acoustic devices requiring high intensity and hypersensitivity in biological ultrasonics, enhanced collimated sound emission (i.e. sound laser) and high-resolution sensing. However, structures reported so far demonstrated a limited quality factor (Q-factor) of acoustic resonances, up to several tens in an open resonator. The emergence of bound states in the continuum (BIC) makes it possible to realize high-Q factor acoustic modes. Here, we report the theoretical design and experimental demonstration of acoustic BICs supported by a single open resonator. We predicted that such an open acoustic resonator could simultaneously support three types of BICs, including symmetry protected BIC, Friedrich-Wintgen BIC induced by mode interference, as well as a new kind of BIC: mirror-symmetry induced BIC. We also experimentally demonstrated the existence of all three types of BIC with Q-factor up to one order of magnitude greater than the highest Q-factor reported in an open resonator.

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