amplifier

放大器
  • 文章类型: Journal Article
    宽带高频和微波信号的放大是每个高频电路和设备中的基本要素。超宽带(UWB)传感器应用使用为其特定应用而设计的电路。本文提出了分析,设计,并实现了基于M序列的UWB应用的超宽带差分放大器。设计的差分放大器基于Cherry-Hooper结构,并以低成本0.35µmSiGeBiCMOS半导体工艺实现。本文介绍了几种设计的分析和实现,重点是对Cherry-Hooper放大器结构的不同修改。所提出的放大器修改集中于在一个主要参数的性能中实现最佳结果。通过电容峰值修改放大器设计以实现最大带宽,具有尽可能低的噪声系数的放大器,描述了专注于实现最高共模抑制比(CMRR)的设计。创建了差分放大器的布局,并制造了芯片并将其引线接合到QFN封装。出于评估目的,设计了一款高频PCB板。原理图模拟,布局后模拟,并对所设计放大器的各个参数进行了测量。设计和制造的超宽带差分放大器具有以下参数:在-3.3V或3.3V时为100-160mA的电源电流,带宽从6到12GHz,增益(在1GHz)从12到16dB,从7到13dB的噪声系数,和高达70dB的共模抑制比。
    Amplification of wideband high-frequency and microwave signals is a fundamental element within every high-frequency circuit and device. Ultra-wideband (UWB) sensor applications use circuits designed for their specific application. The article presents the analysis, design, and implementation of ultra-wideband differential amplifiers for M-sequence-based UWB applications. The designed differential amplifiers are based on the Cherry-Hooper structure and are implemented in a low-cost 0.35 µm SiGe BiCMOS semiconductor process. The article presents an analysis and realization of several designs focused on different modifications of the Cherry-Hooper amplifier structure. The proposed amplifier modifications are focused on achieving the best result in one main parameter\'s performance. Amplifier designs modified by capacitive peaking to achieve the largest bandwidth, amplifiers with the lowest possible noise figure, and designs focused on achieving the highest common mode rejection ratio (CMRR) are described. The layout of the differential amplifiers was created and the chip was manufactured and wire-bonded to the QFN package. For evaluation purposes, a high-frequency PCB board was designed. Schematic simulations, post-layout simulations, and measurements of the individual parameters of the designed amplifiers were performed. The designed and fabricated ultra-wideband differential amplifiers have the following parameters: a supply current of 100-160 mA at -3.3 V or 3.3 V, bandwidth from 6 to 12 GHz, gain (at 1 GHz) from 12 to 16 dB, noise figure from 7 to 13 dB, and a common mode rejection ratio of up to 70 dB.
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  • 文章类型: Journal Article
    流式细胞术是生物医学分析的关键技术,几乎是任何免疫系统研究的重要组成部分。广泛的使用和不断增加的仪器复杂性,然而,导致人们越来越忽视教育的基本操作原则,许多技术的常见情况。本章介绍使用MakeYourOwn流式细胞仪(https://www.cytometryworks.com),可以由学生组装成功能性仪器的有效细胞仪。这个项目和其他类似的项目在生物医学教育中得到了广泛的应用,可以作为志同道合的研究者的模型,他们希望建立自己的系统。它们还提供了良好的机制来引入流式细胞术的关键操作原理,如本文所示。
    Flow cytometry is a critical technology for biomedical analysis and is an essential component of almost any study of the immune system. Widespread usage and increasing instrument complexity have, however, led to increasing neglect of education in their basic operating principles, a common situation with many technologies. This chapter describes the basics of flow cytometer operation using the Make Your Own Flow Cytometer ( https://www.cytometryworks.com ), a working cytometer than can be assembled by students into a functional instrument. This project and others like it is seeing widespread usage in biomedical education and can serve as models for like-minded investigators who wish to build their own systems. They also provide a good mechanism to introduce the key operational principles of flow cytometry as illustrated here.
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  • 文章类型: Journal Article
    The semiconducting carbon nanotube (CNT) has been considered a promising candidate for future radiofrequency (RF) electronics due to its excellent electrical properties of high mobility and small capacitance. After decades of development, great progress has been achieved on CNT-based RF field-effect transistors (FETs). However, almost all elevations are owing to advancement of the CNT materials and fabrication process, while the study of device architecture is seldom considered and reported. In this work, we innovatively combined device architecture and related doping processes to further optimize CNT-based RF FETs by guiding process or materials with collaborative optimization for the first time and explore their effect on device performance carefully and statistically. Based on more mature random-oriented CNT materials, we fabricated CNT-based RF FETs having three different gate positions of device architecture variation accompanied by suitable doping schemes. The optimized FETs obtained 2-3 times of current density (transconductance) and 1.3 times the cutoff frequency and maximum oscillation frequency compared with unoptimized devices at the same channel length. After transistor-level verification of effect, we further built a CNT RF amplifier and demonstrated almost 10 dB of transducer gain improvement operating at 8 GHz for X-band application. The achieved results from this work would help further improve CNT RF performance beyond the materials and process point of view.
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  • 文章类型: Journal Article
    背景:听力损失的老年人难以与护理提供者沟通,住院时死亡率较高(Gentheretal.,2015),即使在控制了年龄和合并症之后.个人听力放大器(PHA),(例如,Pocketalkers™),可以改善与老年患者的沟通。
    方法:我们进行了范围审查,以确定研究空白,并总结了在听力损失患者中使用PHA的临床发现。在完善与听力损失和PHA相关的搜索术语后,我们搜索了MEDLINE,Embase,PsycINFO,科克伦图书馆,CINAHL完成,WebofScience核心合集,ERIC(Proquest),PubMed,ClinicalTrials.gov,国际临床试验注册平台,和国际标准随机对照试验编号登记处。我们确定了1980年至2022年之间以英语发表的文章,这些文章报道了与临床环境中PHA使用相关的经验结果。两名审阅者独立地从文章中提取数据。然后我们将数据整理成证据图,以及总结结果的叙述性回顾。
    结果:从4234个最初确定的标题和摘要,12符合我们作为全文的标准。其中包括三项关于临床医生对PHA的认识和使用情况的调查,对PHA的声学输出的一种评估,和八种干预措施,其中为听力损失患者提供了PHA。这些论文对PHA使用了10个不同的术语,并且在很大程度上没有相互引用。结果显示对PHA的满意度很高,并不断提高言语理解。尽管如此,护理提供者不一致地使用设备,围绕提供商意识的挑战,以及设备维护和位置跟踪。
    结论:PHAs对患者了解其护理提供者的能力具有一致的积极影响,尽管有听力损失。应进一步探讨其在临床环境中使用的障碍和促进因素。
    BACKGROUND: Older adults with hearing loss struggle to communicate with care providers and experience higher mortality rates when hospitalized (Genther et al., 2015), even after controlling for age and comorbidities. Personal hearing amplifiers (PHAs), (e.g., Pocketalkers™), can improve communication with older patients.
    METHODS: We conducted a scoping review to identify research gaps and summarize findings on the clinical use of PHAs with patients with hearing loss. After refining search terms relating to hearing loss and PHAs, we searched MEDLINE, Embase, PsycINFO, Cochrane Library, CINAHL Complete, Web of Science Core Collection, ERIC (Proquest), PubMed, ClinicalTrials.gov, International Clinical Trials Registry Platform, and the International Standard Randomised Controlled Trial Number Registry. We identified articles published in English between 1980 and 2022 that reported empirical outcomes relating to PHA use in clinical settings. Two reviewers independently extracted data from articles. We then organized data into an evidence map, and a narrative review summarizing outcomes.
    RESULTS: From 4234 initially identified titles and abstracts, 12 met our criteria as full texts. These included three surveys on clinicians\' awareness and use of PHAs, one evaluation of the acoustic output of a PHA, and eight interventions wherein PHAs were provided to patients with hearing loss. These papers used 10 different terms for PHAs and largely did not cite one another. Results showed high levels of satisfaction with PHAs, and consistently improved speech understanding. Despite this, care providers used devices inconsistently, with challenges around provider awareness, and device maintenance and location tracking.
    CONCLUSIONS: PHAs have a consistent positive effect on patients\' ability to understand their care providers despite hearing loss. Barriers and facilitators to their use in clinical settings should be further explored.
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  • 文章类型: Journal Article
    设计了基于分支DNA的电化学生物传感器以灵敏地检测特定核酸。在这个平台上,具有三个粘性末端的新型分支DNA可用作生物传感器,以灵敏和特异性地检测核酸。同时,我们还使用分支DNA修饰的AuNP作为信号放大器,以进一步提高灵敏度。分支DNA传感器,靶DNA,和DNA修饰的AuNP形成夹心结构以产生用于靶DNA检测的电子信号。该反应主要涉及DNA杂交而没有庞大的热循环仪和酶。我们证明了杂交反应在不同条件下容易发生,例如NaCl浓度,反应时间,pH值,和温度,除了pH低于4。检测限可以低至0.09pM(S/N=3),具有出色的特异性和选择性。峰电流与靶DNA浓度的对数(0.10pM至10nM)之间存在相关曲线关系。相关系数达到0.987。电化学平台使得分支DNA纳米结构能够确定用于疾病诊断的核酸。
    A branched DNA-based electrochemical biosensor was designed to sensitively detect specific nucleic acids. On this platform, novel a branched DNA with three sticky ends could be used as a biosensor to sensitively and specifically detect nucleic acids. Meanwhile, we also employed branched DNA-modified AuNPs as a signal amplifier to further improve the sensitivity. Branched DNA sensors, target DNA, and DNA-modified AuNPs formed a sandwich structure to produce an electronic signal for target DNA detection. The reaction primarily involved DNA hybridization without bulky thermal cyclers and enzymes. We proved that the hybridization reaction easily occurred under different conditions, such as the NaCl concentration, reaction time, pH, and temperature, except for a pH lower than 4. The limit of detection could go as low as 0.09 pM (S/N = 3) with excellent specificity and selectivity. There was a correlation curve relationship between the peak current and the logarithm of the target DNA concentration (0.10 pM to 10 nM). The correlation coefficient reached 0.987. The electrochemical platform enables a branched DNA nanostructure to determine nucleic acids for disease diagnosis.
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  • 文章类型: Journal Article
    本文提出了一种160GHz,D波段,低噪声放大器(LNA)和D波段功率放大器(PA)在全球创始人22nmCMOSFDSOI中实现。这两种设计用于D波段中生命体征的非接触式监测。LNA基于级联放大器拓扑的多级,其中采用公共源拓扑作为输入和输出级。LNA的输入级设计用于同时输入和输出匹配,而级间匹配网络设计用于最大化电压摆幅。LNA在163GHz实现了17dB的最大增益。在157-166GHz频带中,输入回波损耗非常差。-3dB增益带宽对应于157-166GHz。在-3dB增益带宽内测得的噪声系数在7.6dB和8dB之间。功率放大器在159.75GHz处实现了6.8dBm的输出1dB压缩点。测得的LNA和PA的功耗分别为28.8mW和10.8mW,分别。
    This paper presents a 160 GHz, D-band, low-noise amplifier (LNA) and a D-band power amplifier (PA) implemented in the Global Foundries 22 nm CMOS FDSOI. The two designs are used for the contactless monitoring of vital signs in the D-band. The LNA is based on multiple stages of a cascode amplifier topology with a common source topology adopted as the input and output stages. The input stage of the LNA is designed for simultaneous input and output matching, while the inter-stage-matching networks are designed for maximizing the voltage swing. The LNA achieved a maximum gain of 17 dB at 163 GHz. The input return loss was quite poor in the 157-166 GHz frequency band. The -3 dB gain bandwidth corresponded to 157-166 GHz. The measured noise figure was between 7.6 dB and 8 dB within the -3 dB gain bandwidth. The power amplifier achieved an output 1 dB compression point of 6.8 dBm at 159.75 GHz. The measured power consumptions of the LNA and the PA were 28.8 mW and 10.8 mW, respectively.
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  • 文章类型: Journal Article
    地震的电磁辐射被称为前兆,对于早期警报的目的非常重要。低频波的传播受到青睐,在过去的三十年中,人们对几十mHz到几十Hz之间的范围进行了大量研究。这项工作描述了自筹资金的Opera2015项目,该项目最初由意大利的六个监测站组成,配有电场和磁场传感器,在其他人中。对设计的天线和低噪声电子放大器的洞察提供了性能表征(类似于最佳商业产品)和为我们自己的独立研究复制设计的元素。然后通过数据采集系统测量的信号进行频谱分析,并在Opera2015网站上提供。其他世界知名研究机构提供的数据也被考虑进行比较。该工作提供了处理方法和结果表示的示例,识别自然或人为起源的许多外源噪声贡献。对结果的研究发生了几年,使我们认为,由于显着的衰减和重叠的噪声源的影响,可靠的前兆仅限于地震周围的较短区域。为了这个目标,我们开发了震级-距离指标来对2015年期间观测到的EQ事件的可检测性进行分类,并将其与科学文献中记录的其他一些已知地震事件进行了比较.
    Electromagnetic emissions from earthquakes are known as precursors and are of considerable importance for the purpose of early alarms. The propagation of low-frequency waves is favored, and the range between tens of mHz to tens of Hz has been heavily investigated in the last thirty years. This work describes the self-financed Opera 2015 project that initially consisted of six monitoring stations over Italy, equipped with electric and magnetic field sensors, among others. Insight of the designed antennas and low-noise electronic amplifiers provides both characterization of performance (similar to the best commercial products) and the elements to replicate the design for our own independent studies. Measured signals through data acquisition systems were then processed for spectral analysis and are available on the Opera 2015 website. Data provided by other world-known research institutes have also been considered for comparison. The work provides examples of processing methods and results representation, identifying many exogenous noise contributions of natural or human-made origin. The study of the results occurred for some years and led us to think that reliable precursors are confined to a short area around the earthquake due to the significant attenuation and the effect of overlapping noise sources. To this aim, a magnitude-distance indicator was developed to classify the detectability of the EQ events observed during 2015 and compared this with some other known earthquake events documented in the scientific literature.
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  • 文章类型: Journal Article
    纠缠分布任务遇到了一个问题,即如何准备初始纠缠状态,以便在受到局部噪声时保持尽可能长的纠缠时间。在连续变量状态和局部高斯信道领域,人们很容易假设具有最鲁棒纠缠的最佳初始状态也是高斯的;然而,事实并非如此。在这里,我们证明了特定的非高斯双模状态在确定性局部衰减或放大的作用下保持纠缠(高斯通道,衰减因子/功率增益κi和模式i=1,2的噪声参数μi),每当κ1μ22+κ2μ12<14(κ1+κ2)(1+κ1κ2),与高斯纠缠能够容忍噪声的情况相比,这是一个严格更大的参数区域。这些结果改变了量子信息科学中的“高斯世界”范式(在该范式中,应该在高斯状态下获得涉及高斯通道的优化问题的解决方案)。
    Entanglement distribution task encounters a problem of how the initial entangled state should be prepared in order to remain entangled the longest possible time when subjected to local noises. In the realm of continuous-variable states and local Gaussian channels it is tempting to assume that the optimal initial state with the most robust entanglement is Gaussian too; however, this is not the case. Here we prove that specific non-Gaussian two-mode states remain entangled under the effect of deterministic local attenuation or amplification (Gaussian channels with the attenuation factor/power gain κi and the noise parameter μi for modes i=1,2) whenever κ1μ22+κ2μ12<14(κ1+κ2)(1+κ1κ2), which is a strictly larger area of parameters as compared to where Gaussian entanglement is able to tolerate noise. These results shift the “Gaussian world” paradigm in quantum information science (within which solutions to optimization problems involving Gaussian channels are supposed to be attained at Gaussian states).
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  • 文章类型: Journal Article
    目的:低振幅复合肌肉动作电位(CMAP)提示神经肌肉病理。低振幅也会导致有缺陷的E1电极或其引线,即技术工件。这项研究的目的是研究有缺陷的E2电极引线对CMAP的影响。
    方法:使用标准神经传导方法记录CMAP,并正确连接所有电极引线。然后当E1或E2电极引线与放大器断开时记录信号。这模拟了有缺陷的电极引线。在健康受试者的4条神经中进行研究。
    结果:当E1断开时,CMAP振幅如预期降低。令人惊讶的是,尽管E1已正确连接,但当E2引线断开时,振幅下降了65%以上。
    结论:E1和E2电极有助于CMAP。E1或E2的缺陷记录电极引线导致低振幅CMAP。用断开的E2导线观察到的幅度下降远远大于E2电极记录的信号。这是由于放大器的固有属性,以减少E1和E2输入之间的电压差。当E2引线有缺陷时,CMAP将是E1电极记录的信号的衰减版本,反之亦然。当在所有传导研究中观察到低振幅CMAP振幅时,在探索异常结果的病理基础之前,应考虑技术伪影。
    Low-amplitude compound muscle action potential (CMAP) suggests a neuromuscular pathology. Low amplitude will also result from a defective E1 electrode or its lead, that is, a technical artifact. The aim of this study was to investigate the effect of a defective E2 electrode lead on the CMAP.
    The CMAP was recorded using standard nerve conduction methodology and all electrode leads connected properly. Signals were then recorded when either the E1 or the E2 electrode lead was disconnected from the amplifier. This simulated a defective electrode lead. Studies were performed in four nerves of a healthy subject.
    CMAP amplitude was reduced as expected when E1 was disconnected. Surprisingly, the amplitude fell by more than 65% when the E2 lead was disconnected, although E1 was properly connected.
    E1 and E2 electrodes contribute to the CMAP. A defective recording electrode lead to E1 or E2 results in a low-amplitude CMAP. The amplitude drop observed with a disconnected E2 lead was far greater than the signal recorded by the E2 electrode. This occurs due to the amplifier\'s inherent property to reduce the voltage difference between the E1 and E2 inputs. When E2 lead is defective, the CMAP will be an attenuated version of the signal recorded by the E1 electrode, and vice versa. When low-amplitude CMAP amplitude is observed in all conduction studies, technical artifact should be considered before exploring the pathological basis for the abnormal results.
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  • 文章类型: Journal Article
    目的:小型哺乳动物是自然界中壁虱及其病原体的重要宿主。然而,报道这些关联的研究在巴西仍然很少见。在本研究中,我们调查了在整个大西洋雨林生物群落不同地区捕获的寄生啮齿动物和有袋动物的蜱虫中立克次体DNA的存在,巴伊亚,东北(NE),巴西。
    方法:这项研究是在大西洋森林生物群系内的五个城市进行的,巴伊亚州,在巴西东北部。每个城市都进行了两次运动。对于主机捕获,使用了谢尔曼和战斧陷阱,和陷阱陷阱。被捕获后,宿主被麻醉,他们的整个身体检查蜱。当检测到蜱时,将它们手动取出并储存在含有绝对PA乙醇的eppendorf管(1.5ml)中,用于未来的实验室分析(蜱的鉴定和立克次体的检测.).
    结果:共捕获到609只哺乳动物。总的来说,收集了Ablyomma属和Ixodes属的208个蜱虫:卵卵圆,I.loricatus和A.varium。在卵卵圆中检测到立克次体DNA,它与作为立克次体Parkeri菌株Atlantica雨林存放在GenBank中的序列具有99-100%的同一性。
    结论:这些结果表明,该地区出现了R.parkeri菌株大西洋雨林,卵圆瓶可能是矢量。
    OBJECTIVE: Small mammals are important reservoirs of ticks and their pathogens in nature. However, studies reporting these associations are still rare in Brazil. In the present study, we investigated the presence of Rickettsia DNA in ticks parasitizing rodents and marsupials captured in different areas throughout the Atlantic rainforest biome, Bahia, Northeastern (NE), Brazil.
    METHODS: The study was conducted in five municipalities within of the Atlantic Forest biome, Bahia state, in NE Brazil. Two campaigns were done in each municipality. For host captures Sherman and Tomahawk traps were used, and pitfall traps. After being captured, the hosts were anesthetized and their entire body examined for ticks. When ticks were detected, they were manually removed and stored in eppendorf tubes (1.5 ml) containing absolute PA ethanol for future laboratory analysis (identification of ticks and detection of Rickettsia spp.).
    RESULTS: A total of 609 mammals were captured. Overall, 208 ticks of the genus Amblyomma and Ixodes were collected: A. ovale, I. loricatus and A. varium. Rickettsia DNA was detected in A. ovale and it was 99-100% of identity to the sequence deposited in GenBank as Rickettsia parkeri strain Atlantica rainforest.
    CONCLUSIONS: These results suggest that R. parkeri strain Atlantic rainforest occurs in the region, and A. ovale is likely the vector.
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