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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Design and Evaluation of an L-Band Current-Mode Class-D Power Amplifier Integrated Circuit

Shusta, Michael J 29 August 2014 (has links) (PDF)
Power amplifiers (PAs) convert energy from DC to high frequencies in all radio and microwave transmitter systems be they wireless base stations, handsets, radars, heaters, and so on. PAs are the dominant consumers of energy in these systems and, therefore, the dominant sources of system cost and inefficiency. Research has focused on efficient solid-state PA circuit topologies and their optimization since the 1960s. The 2000s saw the current-mode class-D (CMCD) topology, potentially suitable for today's wireless communications systems, show promise in the UHF frequency band. This thesis describes the design and testing of a high-efficiency CMCD amplifier with an integrated driver stage. In addition, analysis of a merged PA-mixer circuit based on the CMCD is provided.
152

Planar Ultra-Wideband Modular Antenna (PUMA) Arrays for High-Volume Manufacturing on Organic Laminates and BGA Interfaces

LaCroix, James R 21 March 2022 (has links) (PDF)
This work proposes wideband and broadband Planar Ultra-wideband Modular Antenna (PUMA) arrays designed to improve cost and reliability for high production volume commercial and military applications. The designs feature simplified PCB stack-ups with high dielectric constant (Dk) dimensionally stable materials to improve the manufacturing cost and yield. Additionally, the packages use ball grid array (BGA) interconnects, commonly used in digital electronics, for simple solder reflow integration with radio frequency (RF) electronics. While high Dk materials present practical manufacturing benefits, theoretical background will show how and why PUMA arrays lose frequency bandwidth and scan volume with high Dk materials. Further, a band limiting cavity mode will be shown to encroach into the frequency band of high Dk PUMA arrays due to a higher order common mode. PUMA arrays designed on several high Dk materials (Dk = {2.55, 3, 3.7}) will be presented to characterize this reduction in bandwidth. A wideband 7.25-31 GHz (4.3:1) PUMA array-on-package designed on Rogers RO4725JXR (Dk = 2.55) is presented with infinite array simulation results showing good active impedance match, port isolation and cross-polarization performance out to q = 45°. A simplified broadband 15-21 GHz (30%) PUMA array on a thin (λ/11) single layer of Isola FR408HR (Dk = 3.7) is proposed with infinite array results predicting strong active impedance, port isolation and cross-polarization performance with better port isolation and cross-polarization levels than a similar dual-polarized probe fed patch array.
153

半導體研發活動中專案類型與技術特性之研究-以T公司製程研發專案為例

楊宏駿 Unknown Date (has links)
本研究主要採用文獻探討以及個案訪談作為主要的研究方法,先藉由文獻探討建立起論文整體之架構以及相關理論之說明定義所需探討之研究變項,之後再透過台灣半導體標竿企業的製程研發專案訪談加以實證。本研究以研究「專案類型」、「技術知識特質」、與「組織架構特質」對「製程開發的創新活動」的關聯關係來探討台灣半導體製程的研發活動過程並說明所觀察現象的具體意義。另外,並透過研究不同性質的專案來觀察與客戶間的互動關係並說明所觀察到現象以及背後的思考邏輯,進而可得到以下初步之研究結論: 一、製程研發專案的技術與知識特質 1. 不同類型專案中,製程合併型程度越高的專案,其技術知識的內隱性較低、多元性較低、標準化程度較高、路徑相依程度較高。而製程技術標準化與相依度會影響專案成員在研發過程所採取的實驗條件設定的方式,進而在實驗開發階段會影響內隱度。 2. 全新元件的開發可分為兩個層次;第一、元件架構的確立。第二、製造流程的確立。 二、製程研發的團隊組成與研發活動 1. 專案組織架構隨專案類型差異而有明顯差異。製程合併型的專案一般為廠級的開發專案,傾向以「輕型團隊」之方式運作﹔而高度創新的製程研發專案傾向以「重型團隊」之方式運作。 2. 技術知識內隱程度愈高,多元程度程度愈高者愈傾向以試製實驗來共同解決問題。 3. 專案的知識內隱程度愈高越需外部知識的來源;製程研發專案的技術知識的內隱性、多元程度愈高,使用者參與程度愈傾向「共同開發」。 三、組織結構與知識的分享平台 1. 為蓄積、分享重要的技術資訊,成立正式組織統籌規劃高壓製程的研發,並於每季邀集各廠提供相關製程經驗分享。研發經驗會藉由團隊的研發過程與分享制度的建立,進行不同型式的知識轉移。 2. 研發專案團隊內的知識分享機制隨著機密程度不同而有所限制。 四、其他發現 1. 不同產品類別、背景客戶的電路設計習慣不一,可藉適當電路設計於開發時期找出元件的弱點。IDM廠對資料要求度較高,設計師習慣所有的文件資料都具備後才開始設計。 2. 使用者的參與製程開發,可讓新製程依使用者的習慣調整。對製程了解越深入的設計公司,其電路設計越游走合法邊緣。 / This thesis adopts reference and case study as the main research approach. It sets up the thesis whole structure by reference and relevant theories to define the factors. Afterward, to demonstrate the thesis structure by interview three projects about IC manufacture process developing of the company, which is the benchmark semiconductor company in Taiwan. This thesis attempts to take an exploratory study of the relationship between characteristics of project type, characteristics of technological knowledge, characteristics of organization structure, and innovation actitity in process developing on that company in Taiwan. In addition, through the case study, to observe the relationship with customer to explain the phenomenon and thinking in different case.There are primary figures found in the thesis: 1. The characteristics of technological knowledge in process developing projector. a. In different kinds of process developing projects, the combinative multi-process project with low degree in tacit knowledge and pluralism, but with higher degree in standardized and route- interdependence. The degree in process standardized and route- interdependence would influence the experiment condition, which would effects the degree of tacit knowledge in experiment period. b. The development of new device can be divided into two levels: First, the establishment of the device structure. Second, the establishment of the process flow. 2. The developing team make-up and developing activity a. The organization structure has obvious differences in different project type. The combinative multi-process project inclined to with the way operation of ' the light-duty group '; the research and develop with high innovation inclined to with the way operation of ' the heavy-duty group '. b. The projector with high degrree in tacit knowledge and pluralism inclined to solving the problem by the trial-producing experiment. c. Degree of technology diversity determines degree of user engagement in development. Projects with high degree of technology diversity tend to engage user in the joint development mode. Projects with low degree of technology diversity tend to engage user in the “Offering Mode”. 3. Organization structure and the sharing platform of knowledge a. It should build an official organization structure to overall planning developing projectors for knowledge accumulataion and sharing. b. The develipong experiment would be transferred in different type by sharing system building and organization set-up. c. The knowledge sharing of research and develop has limitation in different secret degree. 4. Others a. Different product classification, background of customers has different design style. Could make use of proper circuit design to find out the weakness of device. b. IDM factory require high quality documatation support. Designer used to design afeter all documentation ready, c. The new process could be adjusted according to user’s design style if he participates in the developing project. d. More understanding in process, the circuit design might violade the design rule.
154

Electronic and Magnetic Properties of Two-dimensional Nanomaterials beyond Graphene and Their Gas Sensing Applications: Silicene, Germanene, and Boron Carbide

Mehdi Aghaei, Sadegh 28 June 2017 (has links)
The popularity of graphene owing to its unique properties has triggered huge interest in other two-dimensional (2D) nanomaterials. Among them, silicene shows considerable promise for electronic devices due to the expected compatibility with silicon electronics. However, the high-end potential application of silicene in electronic devices is limited owing to the lack of an energy band gap. Hence, the principal objective of this research is to tune the electronic and magnetic properties of silicene related nanomaterials through first-principles models. I first explored the impact of edge functionalization and doping on the stabilities, electronic, and magnetic properties of silicene nanoribbons (SiNRs) and revealed that the modified structures indicate remarkable spin gapless semiconductor and half-metal behaviors. In order to open and tune a band gap in silicene, SiNRs were perforated with periodic nanoholes. It was found that the band gap varies based on the nanoribbon’s width, nanohole’s repeat periodicity, and nanohole’s position due to the quantum confinement effect. To continue to take advantage of quantum confinement, I also studied the electronic and magnetic properties of hydrogenated silicene nanoflakes (SiNFs). It was discovered that half-hydrogenated SiNFs produce a large spin moment that is directly proportional to the square of the flake’s size. Next, I studied the adsorption behavior of various gas molecules on SiNRs. Based on my results, the SiNR could serve as a highly sensitive gas sensor for CO and NH3 detection and a disposable gas sensor for NO, NO2, and SO2. I also considered adsorption behavior of toxic gas molecules on boron carbide (BC3) and found that unlike graphene, BC3 has good sensitivity to the gas molecules due to the presence of active B atoms. My findings divulged the promising potential of BC3 as a highly sensitive molecular sensor for NO and NH3 detection and a catalyst for NO2 dissociation. Finally, I scrutinized the interactions of CO2 with lithium-functionalized germanene. It was discovered that although a single CO2 molecule was weakly physisorbed on pristine germanene, a significant improvement on its adsorption energy was found by utilizing Li-functionalized germanene as the adsorbent. My results suggest that Li-functionalized germanene shows promise for CO2 capture.
155

Scheduling and Advanced Process Control in semiconductor Manufacturing / Ordonnancement et contrôle avancé des procédés en fabrication de semi-conducteurs.

Obeid, Ali 29 March 2012 (has links)
Dans cette thèse, nous avons examiné différentes possibilités d'intégration des décisions d'ordonnancement avec des informations provenant de systèmes avancés des contrôles des procédés dans la fabrication de semi-conducteurs. Nous avons développé des idées d'intégration et défini des nouveaux problèmes d'ordonnancement originales : Problème d'ordonnancement avec des contraintes de temps (PTC) et problème d'ordonnancement avec l'état de santé des équipement (PEHF). PTC et PEHF ont des fonctions objectives multicritères.PTC est un problème d'ordonnancement des familles de jobs sur des machines parallèles non identiques en tenant compte des temps de setup et des contraintes de temps. Les machines non identiques signifient que toutes les machines ne peuvent pas traités (qualifiés) tous les types de familles d'emplois. Les contraintes de temps nommés aussi Thresholds sont inspirées des besoins de l'APC. Elle est liée à l'alimentation régulière des boucles de contrôle de l'APC. L'objectif est de minimiser la somme des dates de fin et les pertes de qualification des machines lorsqu'une famille de jobs n'est pas ordonnancée sur la machine donnée avant un seuil de temps donné.D'autre part, PEHF est une extension de PTC. Il consiste d'intégrer les indices de santé des équipements (EHF). EHF est un indicateur associé à l'équipement qui donne l'état de la. L'objectif est d'ordonnancer des tâches de familles de jobs différents sur les machines tout en minimisant la somme des temps d'achèvement, les pertes de qualification de la machine et d'optimiser un rendement attendu. Ce rendement est défini comme une fonction d'EDH et de la criticité de jobs considérés. / In this thesis, we discussed various possibilities of integrating scheduling decisions with information and constraints from Advanced Process Control (APC) systems in semiconductor Manufacturing. In this context, important questions were opened regarding the benefits of integrating scheduling and APC. An overview on processes, scheduling and Advanced Process Control in semiconductor manufacturing was done, where a description of semiconductor manufacturing processes is given. Two of the proposed problems that result from integrating bith systems were studied and analyzed, they are :Problem of Scheduling with Time Constraints (PTC) and Problem of Scheduling with Equipement health Factor (PEHF). PTC and PEHF have multicriteria objective functions.PTC aims at scheduling job in families on non-identical parallel machines with setup times and time constraints.Non-identical machines mean that not all miachines can (are qualified to) process all types of job families. Time constraints are inspired from APC needs, for which APC control loops must be regularly fed with information from metrology operations (inspection) within a time interval (threshold). The objective is to schedule job families on machines while minimizing the sum of completion times and the losses in machine qualifications.Moreover, PEHF was defined which is an extension of PTC where scheduling takes into account the equipement Health Factors (EHF). EHF is an indicator on the state of a machine. Scheduling is now done by considering a yield resulting from an assignment of a job to a machine and this yield is defined as a function of machine state and job state.
156

Development of a Lab-on-a-Chip Device for Rapid Nanotoxicity Assessment In Vitro

Shah, Pratikkumar 11 December 2014 (has links)
Increasing useof nanomaterials in consumer products and biomedical applications creates the possibilities of intentional/unintentional exposure to humans and the environment. Beyond the physiological limit, the nanomaterialexposure to humans can induce toxicity. It is difficult to define toxicity of nanoparticles on humans as it varies by nanomaterialcomposition, size, surface properties and the target organ/cell line. Traditional tests for nanomaterialtoxicity assessment are mostly based on bulk-colorimetric assays. In many studies, nanomaterials have found to interfere with assay-dye to produce false results and usually require several hours or days to collect results. Therefore, there is a clear need for alternative tools that can provide accurate, rapid, and sensitive measure of initial nanomaterialscreening. Recent advancement in single cell studies has suggested discovering cell properties not found earlier in traditional bulk assays. A complex phenomenon, like nanotoxicity, may become clearer when studied at the single cell level, including with small colonies of cells. Advances in lab-on-a-chip techniques have played a significant role in drug discoveries and biosensor applications, however, rarely explored for nanomaterialtoxicity assessment. We presented such cell-integrated chip-based approach that provided quantitative and rapid response of cellhealth, through electrochemical measurements. Moreover, the novel design of the device presented in this study was capable of capturing and analyzing the cells at a single cell and small cell-population level. We examined the change in exocytosis (i.e. neurotransmitterrelease) properties of a single PC12 cell, when exposed to CuOand TiO2 nanoparticles. We found both nanomaterials to interfere with the cell exocytosis function. We also studied the whole-cell response of a single-cell and a small cell-population simultaneously in real-time for the first time. The presented study can be a reference to the future research in the direction of nanotoxicity assessment to develop miniature, simple, and cost-effective tool for fast, quantitative measurements at high throughput level. The designed lab-on-a-chip device and measurement techniques utilized in the present work can be applied for the assessment of othernanoparticles' toxicity, as well.
157

Nanofabrication and Spectroscopy of Magnetic Nanostructures Using a Focused Ion Beam

Hadjikhani, Ali 08 July 2016 (has links)
This research used a focused ion beam in order to fabricate record small nano-magnetic structures, investigate the properties of magnetic materials in the rarely studied range of nanometer size, and exploit their extraordinary characteristics in medicine and nano-electronics. This study consists of two parts: (i) Fabrication and study of record small magnetic tunnel junctions (ii) Introduction of a novel method for detection of magnetoelectric nanoparticles (MENs) in the tissue. A key challenge in further scaling of CMOS devices is being able to perform non-volatile logic with near zero power consumption. Sub-10-nm nanomagnetic spin transfer torque (STT) magnetic tunneling junctions (MTJs) have the potential for a universal memory that can address this key challenge. The main problem is to decrease the switching current density. This research studied these structures in sub-10-nm size range. In this range, spin related excitations consume considerably smaller amounts of energy as compared to the larger scale. This research concluded that as predicted a decrease in switching current superior to that of the linear scaling will happen in this size range. Magneto-electric nanoparticles (MENs) can be used to directly couple intrinsic electric-field-driven processes with external magnetic fields for controlling neural activity deep in the brain. These particles have been proven to be capable of inducing deep brain stimulation non-invasively. Furthermore, these magneto-electric nano-particles can be used for targeted drug delivery and are contenders to replace conventional chemotherapy. The circulatory system can deliver a drug to almost every cell in the body; however, delivering the drug specifically into the tumor cell and then releasing it on demand remains a formidable task. Nanomedicine can accomplish this, but ensuring that the drug is released at an appropriate rate once at the target site is an important task. In order to have a complete understanding of the behavior of these MENs when injected into the body, a comprehensive bio-distribution study was performed. This study introduced a novel spectroscopy method for tracing the nanoparticles in the bloodstream. This study investigated the post injection distribution of the MENs in vital organs throughout a period of two months.
158

Design and Characterization of 15nm FinFET Standard Cell Library

Sadhu, Phanindra Datta 01 June 2021 (has links)
The processors and digital circuits designed today contain billions of transistors on a small piece of silicon. As devices are becoming smaller, slimmer, faster, and more efficient, the transistors also have to keep up with the demands and needs of the daily user. Unfortunately, the CMOS technology has reached its limit and cannot be used to scale down due to the breakdown of the transistor caused by short channel effects. Alternative solution to this is the FinFET transistor technology where the gate of the transistor is a 3D fin which surrounds the transistor and prevents the breakdown caused by scaling and short channel effects. FinFET devices are reported to have excellent control over short channel effects, high On/Off Ratio, extremely low gate leakage current and relative immunization over gate edge line roughness. Sub 20 nm is perceived to the limit of scaling the CMOS transistors but FinFETs can be scaled down further due the above-mentioned reasons. Due to these advantages the VLSI industry have now shifted to FinFET in their designs. Although these transistors have not been completely opened to academia. Analyzing and observing the effects of these devices can be pivotal in gaining an in depth understanding of them. This thesis explores the application of FinFETs using a standard cell library developed using these transistors and are analyzed and compared with CMOS transistors. The FinFET package files used to develop these cell is a 15nm FinFET technology file developed by NCSU in collaboration with Cadence and Mentor Graphics. Post design the cells were characterized and then the results were compared to through various CMOS packages to understand and extrapolate conclusions on the FinFET devices.
159

Design and Fabrication Techniques of Devices for Embedded Power Active Contact Lens

Leon, Errol Heradio 01 June 2015 (has links)
This thesis designed and fabricated various devices that were interfaced to an IC for an active contact lens that notifies the user of an event by detection of an external wireless signal. The contact lens consisted of an embedded antenna providing communication with a 2.4GHz system, as well as inductive charging at an operating frequency of 13.56 MHz. The lens utilized a CBC005 5µAh thin film battery by Cymbet and a manufactured graphene super capacitor as a power source. The custom integrated circuit (IC) was designed using the On Semiconductor CMOS C5 0.6 µm process to manage the battery and drive the display. A transparent, flexible, single cell display was developed utilizing electrochromic ink to indicate to the user of an event. Assembly of the components, encapsulation, and molding were implemented to create the final product. The material properties of the chosen substrate were analyzed for their clearness, flexibility, and biocompatibility to determine its suitability as a contact lens material. Finally, the two different fabrication techniques (microfabrication and screen printing) that were employed to make the devices are compared to determine the favorable process for each part of the system.
160

Automated Channel Assessment for Single Chip MedRadio Transceivers

Hillig, Mark Alexander 14 June 2013 (has links)
Modern implantable and body worn medical devices leverage wireless telemetry to improve patient experience and expand therapeutic options. Wireless medical devices are subject to a unique set of regulations in which monitoring of the available frequency spectrum is a requirement. To this end, implants use software protocols to assess the in-band activity to determine which channel should be used. These software protocols take valuable processing time and possibly degrade the operational lifetime of the battery. Implantable medical devices often take advantage of a single chip transceiver as the physical layer for wireless communications. Embedding the channel assessment task in the transceiver hardware would free the limited resources of the microprocessor. This thesis proposes hardware modifications to existing transceiver architectures which would provide an automated channel assessment means for implantable medical devices. The results are applicable beyond medical device applications and could be employed to benefit any low-power, wireless, battery-operated equipment.

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