scholarly journals RF MEMS electrostatically actuated tunable capacitors and their applications: a review

2021 ◽  
Vol 32 (1) ◽  
pp. 013002
Author(s):  
Fahimullah Khan ◽  
Mohammad I Younis
Keyword(s):  
Communication Systems ◽  
Rf Mems ◽  
Building Blocks ◽  
Electrostatically Actuated ◽  
Tunable Capacitors ◽  
Portable Electronics ◽  
Recent Developments ◽  
And Performance ◽  
Micro Electromechanical System ◽  
Insight Into

Abstract This paper reviews the recent developments of micro-electromechanical system (MEMS) based electrostatically actuated tunable capacitors. MEMS based tunable capacitors (MBTCs) are important building blocks in advanced radio frequency communication systems and portable electronics. This is due to their excellent performance compared to solid state counterpart. Different designs, tuning mechanisms, and performance parameters of MBTCs are discussed, compared, and summarized. Several quantitative comparisons in terms of tuning range, quality factor (Q factor), and electrodes configurations are presented, which provide deep insight into different design studies, assists in selecting designs, and layouts that best suit various applications. We also highlight recent modern applications of tunable capacitors, such as mobile handsets, internet of things, communication sensors, and 5G antennas. Finally, the paper discusses different design approaches and proposes guidelines for performance improvement.

scholarly journals RF-MEMS Monolithic K and Ka Band Multi-State Phase Shifters as Building Blocks for 5G and Internet of Things (IoT) Applications

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2612 ◽  
Author(s):  
Jacopo Iannacci ◽  
Giuseppe Resta ◽  
Alvise Bagolini ◽  
Flavio Giacomozzi ◽  
Elena Bochkova ◽  
...  
Keyword(s):  
Internet Of Things ◽  
Communication Systems ◽  
High Speed ◽  
Phase Shifter ◽  
Satellite Communication ◽  
Rf Mems ◽  
Building Blocks ◽  
Phase Shifters ◽  
Small Cells ◽  
Mems Technology

RF-MEMS, i.e., Micro-Electro-Mechanical Systems (MEMS) for Radio Frequency (RF) passive components, exhibit interesting characteristics for the upcoming 5G and Internet of Things (IoT) scenarios, in which reconfigurable broadband and frequency-agile devices, like high-order switching units, tunable filters, multi-state attenuators, and phase shifters will be necessary to enable mm-Wave services, small cells, and advanced beamforming. In particular, satellite communication systems providing high-speed Internet connectivity utilize the K and Ka bands, which offer larger bandwidth compared to lower frequencies. This paper focuses on two design concepts of multi-state phase shifter designed and manufactured in RF-MEMS technology. The networks feature 4 switchable stages (16 states) and are developed for the K and Ka bands. The proposed phase shifters are realized in a surface micromachining RF-MEMS technology and the experimentally measured parameters are compared with Finite Element Method (FEM) multi-physical electromechanical and RF simulations. The simulated phase shifts at both the operating bands fit well the measured value, despite the measured losses (S21) are larger than 5–7 dB if compared to simulations. However, such a non-ideality has a technological motivation that is explained in the paper and that will be fixed in the manufacturing of future devices.

Design and Performance Analysis of Low Pull – in Voltage RF MEMS Shunt Switch for Millimeterwave Therapy, IoT and 5G Applications

2021 ◽  
Author(s):  
Srinivasa rao k ◽  
P. Ashok Kumar ◽  
Girija Srav ◽  
Koushik Guha
Keyword(s):  
Communication Systems ◽  
Rf Mems ◽  
Wave Spectrum ◽  
Signal Propagation ◽  
Micro Electro Mechanical System ◽  
Millimetre Wave ◽  
Smart Systems ◽  
Mems Switch ◽  
Rf Devices ◽  
And Performance

Abstract Recent Advancements in the wireless communication systems utilizes miniaturized devices based on Micro – Electro – Mechanical System technology for present and future 5G wireless applications. Now a days, RF devices are utilizing the frequencies upto 30 GHz and a huge traffic in signal propagation occurs which leads to the slow data rate. In other hand, there is a huge spectrum available in the millimetre wave frequency range of 30 – 300 GHz. The millimetre wave spectrum is attractive for development of smart systems based on 5G technology. In this paper, A low pull – in voltage capacitive type RF MEMS switch is proposed to operate at the frequencies above 30 GHz. The switch is proposed with new iterative meandering technique where span length of each section in meanders differs and dependable with first section. A low pull – in voltage of 1.8V is achieved with large capacitance ratio of 63. The switch exhibits low insertion loss of -0.24 dB at 41 GHz and possess high isolation of -46.7 dB at 38 GHz. The design is validated by comparing the theoretical and simulated results and the switch can be efficiently utilized for millimeterwave applications.

scholarly journals Graphene for Flexible Photovoltaic Devices

2019 ◽  
Vol 6 ◽  
Author(s):  
Kwadwo Mensah-Darkwa ◽  
Rita Namoe Tabi ◽  
Pawan K. Kahol ◽  
Ram K. Gupta
Keyword(s):  
Mechanical Stability ◽  
Low Cost ◽  
Optical Transmittance ◽  
Photovoltaic Devices ◽  
Research Attention ◽  
Portable Electronics ◽  
Recent Developments ◽  
Potential Applications ◽  
And Performance ◽  
Generation Technology

Flexible photovoltaic devices (FPD’s) are emerging as next-generation technology in photovoltaic research. FPD’s have attracted great research attention because of their broad potential applications especially in wearable devices, portable electronics, integrated textiles, unmanned aerial vehicles, transportation, and military etc. The existing technologies have evolved over the years, improving efficiency and performance of photovoltaic devices. However, these technologies mostly rely on rigid electrodes that are brittle, costly and chemically unstable. For FPD’s to become practical, new materials that offer inherent flexibility without compromising on mechanical and optical properties must be the focus. Researchers have made significant advances over the past decade towards developing various aspects of FPD’s to improve its optical transmittance, mechanical stability, chemical stability etc. Graphene is increasingly been recognized as an excellent material for flexible photovoltaic devices because of its unique optical, electrical and mechanical properties. The prospects of introducing an inexpensive and abundant carbon-based material such as graphene in making flexible, low-cost, transparent PV cells cannot be over emphasized. However, the method to synthesize graphene to achieve the best performance is still complicated. This paper presents a brief overview of recent developments made in flexible photovoltaic devices using graphene.

Combinatorial Peptide Libraries for Selecting Inorganic-Binding Proteins: A Step in Molecular Biomimetics

2003 ◽  
Vol 773 ◽  
Author(s):  
C. Tamerler ◽  
S. Dinçer ◽  
D. Heidel ◽  
N. Karagûler ◽  
M. Sarikaya
Keyword(s):  
Binding Proteins ◽  
Building Blocks ◽  
Molecular Engineering ◽  
Inorganic Materials ◽  
Combinatorial Peptide Libraries ◽  
Self Assembling ◽  
Complex Functions ◽  
Recent Developments ◽  
Specific Proteins ◽  
Molecular Biomimetics

AbstractProteins, one of the building blocks in organisms, not only control the assembly in biological systems but also provide most of their complex functions. It may be possible to assemble materials for practical technological applications utilizing the unique advantages provided by proteins. Here we discuss molecular biomimetic pathways in the quest for imitating biology at the molecular scale via protein engineering. We use combinatorial biology protocols to select short polypeptides that have affinity to inorganic materials and use them in assembling novel hybrid materials. We give an overview of some of the recent developments of molecular engineering towards this goal. Inorganic surface specific proteins were identified by using cell surface and phage display technologies. Examples of metal and metal oxide specific polypeptides were represented with an emphasis on certain level of specificities. The recognition and self assembling characteristics of these inorganic-binding proteins would be employed in develeopment of hybrid multifunctional materials for novel bio- and nano-technological applications.

No fear of George Kingsley Zipf

10.1558/37291 ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 242-263
Author(s):  
Stefano Rastelli ◽  
Kook-Hee Gil
Keyword(s):  
Minimalist Program ◽  
Classroom Research ◽  
Language Design ◽  
Efficient Computation ◽  
Generative Linguistics ◽  
The Third ◽  
Factor Effect ◽  
Language Classroom ◽  
Recent Developments ◽  
Insight Into

This paper offers a new insight into GenSLA classroom research in light of recent developments in the Minimalist Program (MP). Recent research in GenSLA has shown how generative linguistics and acquisition studies can inform the language classroom, mostly focusing on what linguistic aspects of target properties should be integrated as a part of the classroom input. Based on insights from Chomsky’s ‘three factors for language design’ – which bring together the Faculty of Language, input and general principles of economy and efficient computation (the third factor effect) for language development – we put forward a theoretical rationale for how classroom research can offer a unique environment to test the learnability in L2 through the statistical enhancement of the input to which learners are exposed.

Green Synthesized Nanomaterials as Theranostic Platforms for Cancer Treatment: Principles, Challenges and the Road Ahead

2019 ◽  
Vol 26 (8) ◽  
pp. 1311-1327 ◽  
Author(s):  
Pala Rajasekharreddy ◽  
Chao Huang ◽  
Siddhardha Busi ◽  
Jobina Rajkumari ◽  
Ming-Hong Tai ◽  
...  
Keyword(s):  
Nanoparticle Synthesis ◽  
Research Field ◽  
Synthesis Methods ◽  
Synthetic Approach ◽  
Future Directions ◽  
The Road ◽  
New Methods ◽  
Recent Developments ◽  
Theranostic Applications ◽  
Insight Into

With the emergence of nanotechnology, new methods have been developed for engineering various nanoparticles for biomedical applications. Nanotheranostics is a burgeoning research field with tremendous prospects for the improvement of diagnosis and treatment of various cancers. However, the development of biocompatible and efficient drug/gene delivery theranostic systems still remains a challenge. Green synthetic approach of nanoparticles with low capital and operating expenses, reduced environmental pollution and better biocompatibility and stability is a latest and novel field, which is advantageous over chemical or physical nanoparticle synthesis methods. In this article, we summarize the recent research progresses related to green synthesized nanoparticles for cancer theranostic applications, and we also conclude with a look at the current challenges and insight into the future directions based on recent developments in these areas.

scholarly journals Cold-Active β-Galactosidases: Insight into Cold Adaption Mechanisms and Biotechnological Exploitation

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 43
Author(s):  
Marco Mangiagalli ◽  
Marina Lotti
Keyword(s):  
Low Temperature ◽  
Molecular Mechanisms ◽  
Building Blocks ◽  
Cold Active ◽  
Cold Adaption ◽  
Glycosyl Donor ◽  
Pharmaceutical Industries ◽  
Biotechnological Processes ◽  
Hydrolysis Of ◽  
Insight Into

β-galactosidases (EC 3.2.1.23) catalyze the hydrolysis of β-galactosidic bonds in oligosaccharides and, under certain conditions, transfer a sugar moiety from a glycosyl donor to an acceptor. Cold-active β-galactosidases are identified in microorganisms endemic to permanently low-temperature environments. While mesophilic β-galactosidases are broadly studied and employed for biotechnological purposes, the cold-active enzymes are still scarcely explored, although they may prove very useful in biotechnological processes at low temperature. This review covers several issues related to cold-active β-galactosidases, including their classification, structure and molecular mechanisms of cold adaptation. Moreover, their applications are discussed, focusing on the production of lactose-free dairy products as well as on the valorization of cheese whey and the synthesis of glycosyl building blocks for the food, cosmetic and pharmaceutical industries.

scholarly journals An overview of psychological and social factors in Charles Bonnet syndrome

2021 ◽  
Vol 13 ◽  
pp. 251584142110347
Author(s):  
Lee Jones ◽  
Lara Ditzel-Finn ◽  
Jamie Enoch ◽  
Mariya Moosajee
Keyword(s):  
Emotional Response ◽  
Causal Mechanism ◽  
Visual Hallucinations ◽  
Cognitively Normal ◽  
Charles Bonnet Syndrome ◽  
Raising Awareness ◽  
Normal Individuals ◽  
The Social ◽  
Recent Developments ◽  
Insight Into

Charles Bonnet syndrome (CBS) is a condition where cognitively normal individuals with sight impairment experience simple and/or complex visual hallucinations. The exact pathogenesis of CBS is unknown; however, deafferentation is often recognised as a causal mechanism. Studies have provided insight into the multifaceted impact of CBS on wellbeing. Onset of CBS may cause distress among those believing visual hallucinations are indicative of a neurological condition. Hallucinatory content is often congruent with the emotional response. For example, hallucinations of a macabre nature typically result in a fearful response. Visual hallucinations may be highly disruptive, causing everyday tasks to become challenging. Clinical management relies on forewarning and pre-emptive questioning. Yet, knowledge and awareness of CBS is typically low. In this review, we provide a summary of the social and psychological implications of CBS and explore recent developments aimed at raising awareness and improving patient management.

Sign in / Sign up

Export Citation Format

Share Document