scholarly journals Micromachined Accelerometers with Sub-µg/√Hz Noise Floor: A Review

Sensors ◽  
2020 ◽  
Vol 20 (14) ◽  
pp. 4054 ◽  
Author(s):  
Chen Wang ◽  
Fang Chen ◽  
Yuan Wang ◽  
Sina Sadeghpour ◽  
Chenxi Wang ◽  
...  
Keyword(s):  
Research And Development ◽  
Quality Factor ◽  
Proof Mass ◽  
Low Noise ◽  
High Quality ◽  
High Scale ◽  
Noise Floor ◽  
Interface Circuit ◽  
Different Types ◽  
Working Principle

This paper reviews the research and development of micromachined accelerometers with a noise floor lower than 1 µg/√Hz. Firstly, the basic working principle of micromachined accelerometers is introduced. Then, different methods of reducing the noise floor of micromachined accelerometers are analyzed. Different types of micromachined accelerometers with a noise floor below 1 µg/√Hz are discussed. Such sensors can mainly be categorized into: (i) micromachined accelerometers with a low spring constant; (ii) with a large proof mass; (iii) with a high quality factor; (iv) with a low noise interface circuit; (v) with sensing schemes leading to a high scale factor. Finally, the characteristics of various micromachined accelerometers and their trends are discussed and investigated.

High-quality factor multipath differential fractal inductor for wireless applications

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sunil Kumar Tumma ◽  
Bheema Rao Nistala
Keyword(s):  
Integrated Circuits ◽  
Quality Factor ◽  
Skin Depth ◽  
Low Noise ◽  
Proximity Effects ◽  
High Quality Factor ◽  
Design System ◽  
High Quality ◽  
Content Type ◽  
Wireless Applications

Purpose The purpose of this study is to develop a high-quality factor fractal inductor for wireless applications such as satellite, WLAN, Bluetooth, microwave, radar and cellular phone. Design/methodology/approach The Hilbert fractal curve is used in the implementation of the proposed inductor. In the proposed inductor, the metal width has split into multiple paths based on the skin depth of the metal. The simulations of the proposed inductor are performed in 180 nm CMOS technology using the Advanced Design System EM simulator. Findings The multipath technique reduces the skin effects and proximity effects, which, in turn, decreases the series resistance of the inductor and attains high-quality factor over conventional fractal inductor for the equal on-chip area. Research limitations/implications The width of the path has chosen higher than the skin depth of the metal for a required operating frequency. Due to cost constraints, the manufacturing of the proposed fractal inductor is limited to a single layer. Practical implications The proposed inductor will be useful for the implementation of critical building blocks of radio frequency integrated circuits and monolithic microwave integrated circuits such as low-noise amplifiers, voltage-controlled oscillators, mixers, filters and power amplifiers. Originality/value This paper presents for the first time the use of a multipath technique for the fractal inductors to enhance the quality factor.

Pictish Horse Carvings

1991 ◽  
Vol 17 (1) ◽  
pp. 53-62
Author(s):  
Irene Hughson
Keyword(s):  
Class Ii ◽  
Class I ◽  
Early Historic Period ◽  
High Quality ◽  
Historic Period ◽  
Agricultural Economy ◽  
Different Types ◽  
Early Historic

Summary This paper examines the horse carvings to be found on Class I and Class II Pictish sculptured stones and considers their reliability as evidence of the sort of horses and ponies that would have existed in the Early Historic Period. An attempt is made to show that the availability in Britain of good sized, high quality riding horses during that period is not inconsistent with what is known of the development and distribution of different types of horses in pre-hislory. The importance of horses and ponies in Early Historic societies is stressed and inferences drawn about the agricultural economy that could support horses and the skilled specialists required to look after them.

A Long Bar Type Silicon Resonator with a High Quality Factor

2014 ◽  
Vol 134 (2) ◽  
pp. 26-31 ◽  
Author(s):  
Nguyen Van Toan ◽  
Masaya Toda ◽  
Yusuke Kawai ◽  
Takahito Ono
Keyword(s):  
Quality Factor ◽  
High Quality Factor ◽  
High Quality ◽  
Type Silicon ◽  
Silicon Resonator

Understanding Deviance in a World of Standards

2020 ◽  
Keyword(s):  
Resource Allocation ◽  
Environmental Protection ◽  
Human Health ◽  
Corporate Responsibility ◽  
Structuration Theory ◽  
High Quality ◽  
Organizational Conditions ◽  
Structure And Agency ◽  
Single Person ◽  
Different Types

Standards have become widespread regulatory tools that promote global trade, innovation, efficiency, and quality. They contribute significantly to the creation of safe, reliable, and high-quality services and technologies to ensure human health, environmental protection, or information security. Yet intentional deviations from standards by organizations are often reported in many sectors, which can either contribute to or challenge the measures of safety and quality they are designed to safeguard. Why then, despite all potential consequences, do organizations choose to deviate from standards in one way or another? This book uses structuration theory—covering aspects of both structure and agency—to explore the organizational conditions and contradictions under which different types of deviance occur. It also provides empirical explanations for deviance in organizations that go beyond an understanding of individual misbehaviour where mainly a single person is held responsible. Case studies of software developing organizations illustrate insightful generalizations on standards as a mechanism of sensemaking, resource allocation, and sanctioning, and provide ground to rethink corporate responsibility when deviating from standards in the ‘audit society’.

scholarly journals Global optimization of an encapsulated Si/SiO$$_2$$ L3 cavity with a 43 million quality factor

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. P. Vasco ◽  
V. Savona
Keyword(s):  
Global Optimization ◽  
Photonic Crystal ◽  
Quality Factor ◽  
State Of The Art ◽  
Optimization Strategy ◽  
High Quality ◽  
Optimal Value ◽  
Out Of Plane ◽  
Fabrication Tolerances ◽  
Structural Imperfections

AbstractWe optimize a silica-encapsulated silicon L3 photonic crystal cavity for ultra-high quality factor by means of a global optimization strategy, where the closest holes surrounding the cavity are varied to minimize out-of-plane losses. We find an optimal value of $$Q_c=4.33\times 10^7$$ Q c = 4.33 × 10 7 , which is predicted to be in the 2 million regime in presence of structural imperfections compatible with state-of-the-art silicon fabrication tolerances.

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