Дисертації з теми "PHEME"
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Basson, Willem Diederick. "Improving Grapheme-based speech recognition through P2G transliteration / W.D. Basson." Thesis, North-West University, 2014. http://hdl.handle.net/10394/11068.
Повний текст джерелаMSc (Computer Science) North-West University, Vaal Triangle Campus, 2014
Casadio, Ylenia Silvia. "Biodegradable PHEMA-based biomaterials." University of Western Australia. School of Biomedical, Biomolecular and Chemical Sciences, 2009. http://theses.library.uwa.edu.au/adt-WU2009.0173.
Повний текст джерелаBennett, Darrell Jonathan. "Properties of crosslinked phema hydrogels /." Title page, contents and introduction only, 1991. http://web4.library.adelaide.edu.au/theses/09PH/09phb4713.pdf.
Повний текст джерелаHaris, Norshakila. "Three-dimensional multilayer integration and characterisation of CPW MMIC components for future wireless communications." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/threedimensional-multilayer-integration-and-characterisation-of-cpw-mmic-components-for-future-wireless-communications(89ddea33-4de2-43ba-b8dc-dbc032b868e7).html.
Повний текст джерелаBéland, Paul. "Millimeter-wave noise characterization of PHEMT devices." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq26300.pdf.
Повний текст джерелаSeng, Hing Weng. "Exploitation of phemt in microwave power limiters." Thesis, University of Manchester, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.594759.
Повний текст джерелаJasper, David Brian. "RF pHEMT Switch Model for Multiband Cell Phone Circuits." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-11032004-220504/.
Повний текст джерелаMartins, Everson. "Projeto de misturador com topologia celula de Gilbert utilizando pHEMT." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260267.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e de Computação
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Doutorado
Mat, Jubadi Warsuzarina. "Modelling of advanced submicron gate InGaAs/InAlAs pHEMTs and RTD devices for very high frequency applications." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/modelling-of-advanced-submicron-gate-ingaasinalas-phemts-and-rtd-devices-for-very-high-frequency-applications(4688a951-f235-4720-93e4-441eabcce44a).html.
Повний текст джерелаLorenzetti, Solange Gubbelini. ""Obtenção dos sistemas bioconjugados Crotoxina/PEBD-g-Phema e Crotoxina/PCL"." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/85/85131/tde-08062007-132650/.
Повний текст джерелаThe aim of the work was the obtainment of polymeric matrices immobilized with crotoxin purified from crude venom of rattle snake. A matrix was processed by gamma irradiation by the grafting of a hydrogel onto a polymeric film which resulted in a copolymer for the chemical immobilization of crotoxin. The second matrix was attainned by the entrapment of crotoxin in microspheres of epsilon-polycaprolactone. After the purification, the crotoxin proceeding from the snake Crotalus durissus terrificus was evaluated biochemical and biologically. The letal dose (LD50%) of the toxin was 0.09/kg animal. The test of cytotoxicity not revealed any significant difference between the tumoral cells and the respective normal control cells in culture. Grafting copolymers were used as scaffold for the chemical immobilization of the purified crotoxin. For this purpose the low density polyethylene (LDPE) and the hydrophilic monomer 2-hydroxy-ethyl-methacrylate (HEMA) were copolymerized in a 60Co source. The copolymers (LDPE-g-PHEMA) showed grafting levels in the range of 2 and 50 %. In the infrared spectroscopy analysis (FTIR-ATR) it was observed in the copolymer, carbonyl groups (C=O) and hydroxyl groups OH due to the grafting of PHEMA. The MEV micrographies showed a smooth surface for the virgin LDPE and a rough surface for the LDPE-g-PHEMA, owing to the presence of grafted PHEMA. The hydrophilicity was observed by the determination of water content in the copolymer after immersion in water. By the diffusion coefficient it was noted that from 30 % grafting degree, the copolymers become less hydrophilic due to the crosslinking increase among the chains in PHEMA. The biocompatibility of the LDPE-g-PHEMA was proved by the cytoxicity test. At the end, the immobilized copolymer, the entraped crotoxin and the free crotoxin was tested in vivo. During 20 days, C3H strain mouses were observed in ix their weight, behavior and motor changes. The results demonstrated that the group injected with crotoxin had visible loss of weight higher than the other groups. It was concluded that, potentially the immobilized crotoxin could be used by its catalitic phospholipase action, possibily for the hydrolysis of phopholipids present in human serum low density lipoproteins (LDL). By the other side, the entraped crotoxin in the microspheres of epsilon-polycaprolactone could be employed in the managed drug delivered system for the tumoral therapy.
SILVA, CLAUMIR SARZEDA DA. "PHEMT BALANCED PARAMETRIC FREQUENCY DIVIDER BY TWO FOR ELECTRONIC DEFENSE RECEIVERS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=15236@1.
Повний текст джерелаEste trabalho aborda o desenvolvimento de divisores de freqüência por dois paramétricos balanceados a PHEMT, tendo, como motivação, seu emprego como conversores de freqüência em receptores digitais de Defesa Eletrônica. Estes dispositivos têm como características importantes a simplicidade de projeto, um número reduzido de componentes, a possibilidade de integração em circuitos monolíticos de microondas (MMIC), coerência de fase, banda de operação larga, resposta a sinal pulsado muito boa, supressão de harmônicos boa, insensibilidade a variações térmicas e ruído de fase baixo. Uma metodologia de projeto passo a passo é proposta, norteada pela obtenção de dispositivos com ganho máximo (ou perdas mínimas) e banda de operação maximizada. Duas configurações de circuito são consideradas: com ressoadores em paralelo (linhas acopladas) e em série. A caracterização dos divisores é realizada por meio de simulação e experimentalmente. Por fim, uma análise comparativa com a literatura disponível é apresentada, mostrando que alguns dos circuitos desenvolvidos e realizados alcançaram melhor desempenho.
This work assesses the development of PHEMT balanced parametric frequency dividers by two, intended for application as frequency converters on Electronic Defense digital receivers. The main characteristics of these devices are design simplicity, reduced number of components, possibility of integration in MMIC, phase coherence, wide bandwidth, very good pulse response, good harmonic suppression, insensitivity to thermal variations and low phase noise. A step-by-step design methodology is proposed, guide by maximum gain (or minimum loss) and maximized band device requirements. Two circuit topologies are considered: with either parallel (coupled lines) or series resonators. The characterization of the dividers is performed both through simulation and experimentally. Finally, a comparative analysis against literature results is presented, evidencing that some of the developed circuits achieve better performance.
LORENZETTI, SOLANGE G. "Obtenção dos sistemas bioconjugados crotoxina/PEBD-g-PHEMA e crotoxina/PCL." reponame:Repositório Institucional do IPEN, 2006. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11447.
Повний текст джерелаMade available in DSpace on 2014-10-09T13:57:06Z (GMT). No. of bitstreams: 0
Dissertação (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
Reinholm, Sanna. "Fenotypning med Phene Plate system av koagulas-negativa stafylokocker isolerade från centrala venkatetrar." Thesis, Örebro universitet, Hälsoakademin, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-11039.
Повний текст джерелаGrenik, Elizabeth Monica. "Chemical Modification of PHEMA to Create an Improved Bioactive Biomaterial for Regenerative Applications." Thesis, Curtin University, 2016. http://hdl.handle.net/20.500.11937/49779.
Повний текст джерелаSadeghi, Mohammadreza. "Highly sensitive nano Tesla quantum well Hall Effect integrated circuits using GaAs-InGaAs-AlGaAs 2DEG." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/highly-sensitive-nano-tesla-quantum-well-hall-effect-integrated-circuits-using-gaasingaasalgaas-2deg(cec2fce1-7cf5-4d36-918d-873e0d38cac0).html.
Повний текст джерелаHäfele, Martin. "High-speed wideband GaAs PHEMT amplifiers for 40 gb/s fiber-optic communication systems." Göttingen Cuvillier, 2009. http://d-nb.info/99641861X/04.
Повний текст джерелаIan, Ka Wa. "Routes to cost effective realisation of high performance submicron gate InGaAs/InAlAs/InP pHEMT." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/routes-to-cost-effective-relisation-of-high-performance-submicron-gate-ingaasinalasinp-phemt(5aac071c-a4c8-48c7-aadf-e1f3e562e384).html.
Повний текст джерелаSajedin, M., Issa T. Elfergani, Jonathan Rodriguez, Raed A. Abd-Alhameed, M. Fernandez-Barciela, and M. Violas. "Ultra-Compact mm-Wave Monolithic IC Doherty Power Amplifier for Mobile Handsets." MDPI, 2021. http://hdl.handle.net/10454/18600.
Повний текст джерелаThis work develops a novel dynamic load modulation Power Amplifier (PA) circuity that can provide an optimum compromise between linearity and efficiency while covering multiple cellular frequency bands. Exploiting monolithic microwave integrated circuits (MMIC) technology, a fully integrated 1W Doherty PA architecture is proposed based on 0.1 µm AlGaAs/InGaAs Depletion- Mode (D-Mode) technology provided by the WIN Semiconductors foundry. The proposed wideband DPA incorporates the harmonic tuning Class-J mode of operation, which aims to engineer the voltage waveform via second harmonic capacitive load termination. Moreover, the applied post-matching technique not only reduces the impedance transformation ratio of the conventional DPA, but also restores its proper load modulation. The simulation results indicate that the monolithic drive load modulation PA at 4 V operation voltage delivers 44% PAE at the maximum output power of 30 dBm at the 1 dB compression point, and 34% power-added efficiency (PAE) at 6 dB power back-off (PBO). A power gain flatness of around 14 ± 0.5 dB was achieved over the frequency band of 23 GHz to 27 GHz. The compact MMIC load modulation technique developed for the 5G mobile handset occupies the die area of 3.2.
This research was funded by the European Regional Development Fund (FEDER), through COMPETE 2020, POR ALGARVE 2020, Fundação para a Ciência e a Tecnologia (FCT) under i-Five Project (POCI-01-0145-FEDER-030500). This work is also part of the POSITION-II project funded by the ECSEL joint Undertaking under grant number Ecsel-345 7831132-Postitio-II-2017-IA. This work is supported by FCT/MCTES through national funds and when applicable co-funded EU funds under the project UIDB/50008/2020-UIDP/50008/2020. The authors would like to thank the WIN Semiconductors foundry for providing the MMIC GaAs pHEMT PDKs and technical support. This work is supported by the Project TEC2017-88242-C3-2-R- Spanish Ministerio de Ciencia, Innovación e Universidades and EU-FEDER funding.
Déchansiaud, Adeline. "Conception, modélisation et caractérisation de cellules de puissance innovantes en technologie MMIC pour des applications spatiales." Limoges, 2012. https://aurore.unilim.fr/theses/nxfile/default/4b52fe2b-3c3b-4b52-98c8-3ee51417530c/blobholder:0/2012LIMO4056.pdf.
Повний текст джерелаThis report deals with the reduction of Ku-band power amplifiers area used in VSAT equipments. Therefore, a new unitary power cell called ≪ Integrated cascode ≫ has been designed. This new cell is composed of two MMIC GaAs transistors of the UMS PPH25X foundry. The sources of the first transistor exhibit via holes. These via holes ensure a high gain and a good thermal stability. Moreover, a distributed approach can be adopted (components integration between gate fingers). They also allow a perfect symmetry of the structure. The number of unitary cell can be adjusted in order to deliver the global power expected. The shape factor of the integrated cascode is equal to 1 whereas the shape factor of a single transistor with the same gate development is equal to 4. This cell has been measured and its model has been validated. The integrated cascode has been used to design a 2W MMIC Ku-band amplifier. The amplifier area is decreased of 40 %
Shinghal, Priya. "Ultra-broadband GaAs pHEMT MMIC cascode Travelling Wave Amplifier (TWA) design for next generation instrumentation." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/ultrabroadband-gaas-phemt-mmic-cascode-travelling-wave-amplifier-twa-design-for-next-generation-instrumentation(37fc42a1-d865-4ee9-bd19-35b5699249b2).html.
Повний текст джерелаWebber, Scott. "Design of Ultra Wideband Low Noise Amplifier for Satellite Communications." Thesis, University of North Texas, 2020. https://digital.library.unt.edu/ark:/67531/metadc1703346/.
Повний текст джерелаMirous, Brian K. "SYNTHESIS AND PRESUMPTIVE CROSSLINKING OF STIMULI-RESPONSIVE DIBLOCK POLYMER BRUSHES." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1144783034.
Повний текст джерелаAsad, Bashar Z. J. "Low-Noise 24 GHz 0.15μm GaAs pHEMT Gilbert Cell Mixer for Intelligent Transportation System Radar Receiver". Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31547.
Повний текст джерелаSteighner, Jason. "Investigation and trade study on hot carrier reliability of the PHEMT for DC and RF performance." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5048.
Повний текст джерелаID: 030423238; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.)--University of Central Florida, 2011.; Includes bibliographical references (p. 46-47).
M.S.
Masters
Electrical Engineering and Computer Science
Engineering and Computer Science
Lima, Lonetá Lauro 1982. "Contribuição à fabricação e caracterização de hidrogéis de pHEMA com objetivo de produção de cartilagem artificial." [s.n.], 2013. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263527.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica
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Resumo: A área de biomateriais tem crescido e desenvolvido tecnologias para acompanhar e suprir as demandas que tem surgido a cada dia na área médica. Os novos biomateriais são produtos versáteis que atuam, combatem ou reparam inúmeras limitações e patologias. Dentro da classe de biomateriais poliméricos os hidrogéis têm sido cada vez mais estudados devido as suas características serem adequadas para várias aplicações biomédicas, dentre elas a cartilagem articular. As tecnologias de fabricação também tem acompanhado o desenvolvimento dos biomateriais. A prototipagem rápida tem impulsionado as pesquisas na área biomédica e permitido a biofabricação de estruturas complexas que existe no corpo humano e de animais. A biofabricação integra os fundamentos da engenharia e o conhecimento da área biomédica para produzir dispositivos biocompatíveis que possam ser utilizados na área biomédica. Esse trabalho é um estudo para verificar a viabilidade de fabricar substratos de poli (metacrilato de 2-hidroxietila) (pHema) usando um equipamento desenvolvido pelo grupo de pesquisadores do INCT Biofabris da Unicamp. Esse equipamento de biofabricação utiliza os princípios da estereolitografia por irradiação direta com luz UV-Visível para fabricar dispositivos médicos Os substratos foram produzidos utilizando seis diferentes composições químicas, para verificar a influência da composição química nas propriedades mecânicas, biológicas e biotribológicas dos hidrogéis. Foi verificado que os substratos produzidos com maior densidade de reticulação promove maior proliferação celular
Abstract: The development of biomaterials area has grown and has developed technologies aimed to satisfy the demands that emerge every day in the medical field. New biomaterials are versatile products that act and repair numerous limitations and diseases. Within the class of polymeric biomaterials, hydrogels have been increasingly studied due to their characteristics that are suitable for various biomedical applications, such as articular cartilage. Manufacturing technologies have also followed the development of biomaterials. Rapid prototyping has driven research in the biomedical field and has allowed the biomanufacturing of complex structures that exist in the human and animals' body. The biomanufacturing integrates the fundamentals of engineering and biomedical knowledge to produce biocompatible devices that can be used in the biomedical field. This work is a study to verify the feasibility for fabrication of substrates of poly (2-hydroxyethyl methacrylate) (pHema) using an equipment developed by the research group of INCT Biofabris Unicamp. This equipment is based on the principle of stereolithography by direct irradiation with UV- visible light to fabricate medical devices. The substrates were produced using six different chemical compositions in order to verify the influence of the chemical composition on the mechanical properties, biological and biotribological properties of hydrogels. It was found that the substrate produced with higher crosslinking density promotes greater cell proliferation
Doutorado
Materiais e Processos de Fabricação
Doutora em Engenharia Mecânica
Taggueb, Hassiba. "Conception d'amplificateurs transimpédance pour la photoreception dans des liaisons optiques à haut débit." Paris 6, 2007. http://www.theses.fr/2007PA066377.
Повний текст джерелаOptoelectronic interfaces are the heart of optical fiber communication systems. This work describes the optimisation of photoreception front end circuit associating a photodetector with a preamplifier. This preamplifier is one of the most critical components in the photoreception system, because it determines mainly its sensitivity. Considering the state of art of the front-end circuits, our choice was made on transimpédance amplifier (TIA) with negative feedback. Several transimpedance amplifier (TIA) architectures were optimised and realised with two different GaAs MMIC technologies (OMMIC and Win Semiconductor). The principal constraints fixed by the considered applications are circuit compactness, bandwidth (more than 12 GHz), transimpedance gain (more than 47 dB), dynamic range and low consumption. Two identical TIA structures have been implemented on the same chip with dimension of 1 x 1. 5 mm2. The performances comparison of these various circuits, associated with retro-simulations, highlighted the need of having accurate active components models, mainly at high frequencies. Solutions are also proposed to improve the photoreceiver performances, associating one of these TIAs with a photodiode, specifically for bandwidth broadening
Wang, Zhengmu. "Design, fabrication and characterization of a double-network alginate-pHEMA hydrogel coating for PDMS-based biomedical implants." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/61102.
Повний текст джерелаApplied Science, Faculty of
Mechanical Engineering, Department of
Graduate
Mays, Kenneth W. "A 40 GHz Power Amplifier Using a Low Cost High Volume 0.15 um Optical Lithography pHEMT Process." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/552.
Повний текст джерелаAhdjoudj, Mourad. "Conception de vco a faible bruit de phase en technologie monolithique phemt dans les bandes k et ka." Paris 6, 1997. http://www.theses.fr/1997PA066595.
Повний текст джерелаMohamad, Isa Muammar Bin. "Low Noise Amplifiers using highly strained InGaAs/InAlAs/InP pHEMT for implementation in the Square Kilometre Array (SKA)." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/low-noise-amplifiers-using-highly-strained-ingaasinalasinp-phemt-for-implementation-in-the-square-kilometre-array-ska(31b6cbae-7b7e-43fe-a612-b3555dd2263d).html.
Повний текст джерелаJacob, Kane, and Bala Bhaskar Gudey. "Co-Design of Antenna and LNA for 1.7 - 2.7 GHz." Thesis, Linköpings universitet, Fysik och elektroteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-85953.
Повний текст джерелаMonção, Ana Paula dos. "Sintese de hidrogeis de phema para liberação controlada de drogas e meios acido e neutro e estudo da difusão." [s.n.], 1997. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267384.
Повний текст джерелаDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Neste trabalho, hidrogéis de poli(2-hidroxietil metacrilato) ¿ PHEMA foram preparados por reticulação química, usando N,N¿ metileno ¿ bis ¿ acrilamida como agente reticulante. Hidrogéis de diferentes graus de reticulação foram obtidos variando-se a concentração do reticulante de 0,12% a 3% (p/p). Os filmes de PHEMA obtidos foram caracterizados através de análise de calorimetria diferencial de varredura ¿ DSC, microscopia eletrônica de varredura ¿ MEV e ensaio de tração. Dentre essas análises, o ensaio de tração foi o que mais mostrou as alterações das propriedades dos hidrogéis obtidos. O intumescimento foi estimado a partir da variação ocorrida no peso das amostras quando atingiram o equilíbrio, imersas em água destilada e solução tampão a pH=1, à temperatura ambiente. Observou-se que há influencia do meio externo no intumescimento do hidrogel. Os estudos da difusão foram realizados utilizando-se Rodamina B como espécie difusiva. As análises de difusão foram realizadas a ¿37 GRAUS¿C, em solução tampão de pH=1 e água destilada, pH~7. o coeficiente de difusão do soluto (D) foi calculado através da '2 POT. a¿ lei de Fick. Os dados experimentais obtidos e a elaboração de um modelo matemático permitiram a avaliação do coeficiente de difusão, utilizando-se métodos numéricos iterativos, os resultados obtidos mostraram que há reticulação física na formação do hidrogel de PHEMA, permitindo a sua utilização sem agente reticulante. Com a adição do agente reticulante, observou-se uma significativa alteração do coeficiente de difusão
Abstract: In this work, hydrogels of poly (2 ¿ hydroxyethyl methacrylate) ¿ PHEMA were prepared by chemical crosslinks using N, N¿methylene ¿ bis ¿ acrylamide as the crosslinking agent. Hydrogels with different crosslinking degrees were obtained by varying the crosslinker concentration from 0.12% up to 3.0% (w/w). the films of PHEMA obtained were characterized by differential scanning calorimetry ¿ DSC, scanning electron microscopy ¿ MEV and mechanical properties. The mechanical tensile test was the method of characterization that showed more properties variation of the hydrogels obtained. The swelling was estimated by the variation in the samples weight when they reached the equilibrium, after have been immersed into distilled water and buffer solution at room temperature. It was observed that there is influence of the pH in the hydrogel swelling. The diffusion studies were carried out using Rhodamine B as the diffusive model specimen. The diffusion analysis were conducted at ¿37 GRAUS¿C, in buffer solution at pH=1 and distilled water at pH~7. The Fick¿s Second Law has been used to calculate the solute diffusion coefficient (D). The experimental data obtained and the mathematical model elaborated permited the evaluation of diffusion coefficient using iterative numerical methods. The results obtained have shown that there is physical crosslinking in the PHEMA hydrogel formation, so its utilization without crosslinker was permited. A significative variation of the diffusion coefficient was observed when the crosslinking agent was added.
Mestrado
Ciencia e Tecnologia de Materiais
Mestre em Engenharia Química
Vildeuil, Jean-Charles. "Caractérisation et modélisation basse fréquence de transistors PHEMT AlGaAs/InGaAS/GaAs : bruits du canal, de la grille et corrélation." Montpellier 2, 2000. http://www.theses.fr/2000MON20151.
Повний текст джерелаTan, Jimmy Pang Hoaw. "Thermal and small-signal characterisation of AlGaAs/InGaAs pHEMTs in 3D multilayer CPW MMIC." Thesis, University of Manchester, 2011. https://www.research.manchester.ac.uk/portal/en/theses/thermal-and-smallsignal-characterisation-of-algaasingaas-phemts-in-3d-multilayer-cpw-mmic(4a663463-af52-4a35-a570-01ca41e2baa0).html.
Повний текст джерелаAmsaaed, Salem. "Copper Grafted Titanium Dioxide in Hydrogels for Photocatalysts." DigitalCommons@Robert W. Woodruff Library, Atlanta University Center, 2018. http://digitalcommons.auctr.edu/cauetds/155.
Повний текст джерелаSHARMA, HARSHITA. "SOFT COMPUTING FOR RUMOUR ANALYTICS ON BENCHMARK TWITTER DATA." Thesis, 2019. http://dspace.dtu.ac.in:8080/jspui/handle/repository/16701.
Повний текст джерела洪國瀛. "pHEMT Antenna Switch." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/18587502090994435879.
Повний текст джерела明新科技大學
電機工程研究所
95
pHEMT antenna switch has been widely used into advanced monolithic microwave integrated circuits (MMIC) for modern microwave system applications. The advantages of the AlGaAs/InGaAs pseudomorphic high-electron-mobility transistor(pHEMT) antenna switch are low insertion loss , high isolation , and high power handling. A double pole double throw (DPDT) switch has been fabricated and tested for DC-6GHz application. The number of the gate finger is chosen as 2 , and the die area is 1278μm x 1154μm .The control voltage used for the switch is 3V. The measured insertion loss is 1.1dB at 2.45GHz. The isolation of the device is 47dB, and the power 1dB compression point (P1dB) is 30 dBm . The insertion loss is 1.1 dB , the isolation is 35dB, and P1dB is 29.5 dBm at 5.8GHz. A typical application of the DPDT switch is for diversity antenna switching in IEEE 802.11a/b/g Wireless LAN systems. In future, the 4P4T switch will be studied for MIMO application.
Chang, Jhe-jia, and 張哲嘉. "Equivalent Circuit Model of pHEMT." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/76983379795309628889.
Повний текст джерела國立雲林科技大學
光學電子工程研究所
95
In this thesis, device models are established for pHEMTs. The device models include a small-signal model and a large-signal model. Conventionally, Yang-Long’s measurement technique was used to extract the source parasitic resistance Rs, and then the cold-FET measurement was performed to extract other parasitic parameters of small-signal model. After extracting the parasitic parameters, one removes the parasitic effects to obtain the intrinsic equivalent circuit of pHEMTs with mathematic algorithms. Finally, using Y-parameters in the intrinsic circuit, one can calculate the intrinsic parameters. In contrast, a new technique using the influence of high-frequency parameters on high-frequency characteristics is proposed in this thesis. A specific procedure of several steps is presented to extract parameters of the small signal model systematically, and the extracted result is satisfactory. To extract DC parameters in the large signal model, equations of the EEHEMT model are used. A specific procedure of extracting DC parameters is developed without using the IC-CAP extraction software. DC characteristics are measured to extract the parameters of the large signal model. Simulation using the ADS (Advanced Design System) software is compared with measurement. The simulated result closely matches the DC measurement. The research results also provide a better insight into the EEHEMT model.
Tu, Min-Chang, and 杜明昌. "Optimization of HBT/pHEMT integration technology." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/92327930388865958989.
Повний текст джерела國立中山大學
電機工程學系研究所
98
The InGaP Heterojunction Bipolor Transistors (HBTs) become known as the dominant technology in handset power amplifiers. Modern application requirements and size limitations have driven industry leaders towards the co-integration of enhance/depletion mode pHEMT and HBT. The combination of BiFET gives an additional degree of freedom in the design of advanced power amplifiers combine switch. This dissertation provides an overview of the various techniques. Critical processes included gate photolithography and Polyimide planarize process are discussed in detail. The 0.5-μm multiple gate fingers fabricated on the controllable small un-gated region of a high-topology wafer was overcome by using a bi-layer photolithography process. The fabricated of polyimide was used as the dielectric interlayer to reduce the interconnect crossover parasitic capacitance and planarize the second metal process for metal shunt application. The metal shunt structures provide greater functionality and design flexibility under shrinking. Finally, presents the combine the best features of InGaP HBT-pHEMT integration technology. The HBT and E/D-pHEMT electrical performances (DC, small signal, noise, and power) are presented. The results indicate that this technology offers great potential and degrees of freedom to design power amplifiers, high-integrated RF transceivers, and opportunities for the development of novel RFIC circuits.
郭李瑞. "PHEMT T/R Switch for Wireless Application." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/45732409372720201572.
Повний текст джерела明新科技大學
電機工程研究所
93
Transmit/Receive (T/R) switch has been widely used into advanced monolithic microwave integrated circuits (MMIC) for modern microwave system applications. The advantages of the AlGaAs/InGaAs pseudomorphic high-electron-mobility transistor (PHEMT) T/R switch are : low Insertion loss, high Isolation, low control voltage , small size, and high power handling. A single pole double throw (SPDT) pHEMT T/R switch has been fabricated and tested for DC-6GHz applications. The number of the gate finger is chosen as 2, and the gate width is 1650um. In this paper, The performance of the switch was compared with the different gate widths, gate number and different value of capacitors. The control voltage used for the switch is 3.0V. The measured Insertion loss is 0.36dB at 2.4GHz. The Isolation of the device is 26dB, and the power 1dB compression point is 26dBm. The Insertion loss is 1.7dB, and the Isolation is 17dB at 5.8GHz. This switch is used for the IEEE802.11a/b/g applications.
Peng, AnSam, and 彭安賢. "The Analysis of HBT and PHEMT Power Devices." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/92869971566581023621.
Повний текст джерела國立中興大學
電機工程學系
89
With the rapid developments of wireless communication , Power Amplifiers (PA) not only require high output power, power-added efficiency, but also high linearity. For the performance of power amplifiers, the most important components are the power devices we used. The most widely used power devices are PHEMT and HBT now. Therefore this thesis focuses on the characteristics of PHEMT and HBT and performs several power measurements. In addition, we analyze the gain compression mechanism and different impedance load lines. This thesis is divided into three subjects. The first subject is the basic concepts of power measurement and load impedance. In the second subject we analyze the gain compression of PHEMT, such as knee voltage, pinch-off voltage, breakdown voltage, the maximum drain current and other characteristics. In the last subject we study the most important power device, HBT. HBT have very different bias operation and gain compression mechanism from PHEMT, such as Class-A operation, knee voltage, beakdown voltage, constant base voltage. In this thesis, we carefully analyze the power characteristics of these power devices in detailed and develop a new peculiar way to characterize the different gain compression mechanism. The influence of power in different load lines is also studied.
Bai, Jing-Shian, and 白景賢. "Research of V-band pHEMT Cascode Power Amplifiers." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/18292076476272349460.
Повний текст джерела國立臺灣大學
電信工程學研究所
99
In this thesis, three high frequency amplifiers are designed and investigated, including a V-band buffer amplifier, a V-band power amplifier and a 67-GHz power amplifier. These three circuits are implemented using pseudomorphic high electron mobility transistor (pHEMT) technology. The first part of this thesis describes the design of a buffer amplifier for V-band applications using 0.15-um low-noise pHEMT technology. The circuit consists of two stages cascode amplifier and designed using coplanar waveguide (CPW) structure to reduce the parasitic effect. The measured small signal gain is about 18 dB, and the measured saturation output power is about 3.5 dBm at 60 GHz. A power amplifier with high output power in 0.15-um power pHEMT technology is presented next. This circuit is also a two-stage design adopting cacode configuration as the driver stage and common-source configuration as the power stage. The measured saturation output power is about 22 dBm at 60 GHz. Finally, a 67-GHz power amplifier using 0.15-um low-noise pHEMT technology is presented. This circuit is realized with two-stage cascode configuration to achieve high gain and high output power. The consideration of power budget and balanced structure using Lange coupler are discussed in this chapter. There are discrepancies between simulation results and measurement results, and the reason will be discussed also. Because of the inaccuracy of the transistor model at higher frequency, the simulation results of the circuit do not agree with the measurement results. The linear model parameters are re-generated with the measured device data provided by the foundry WIN Semiconductors. Based on the new linear model parameters and the dc-IV curves, the Angelov model is established. With the new nonlinear model, the simulation results and measurement results of the circuits show better agreement.
Chiou, Zeng-Gang, and 邱振剛. "pHEMT RFIC Design of Wideband Low Noise Amplifier." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/qud9ky.
Повний текст джерела國立虎尾科技大學
光電與材料科技研究所
99
This thesis presents the design of ultra-wideband low noise amplifier (LNA) using WIN 0.15μm pHEMT process to design the circuit. Three frequency bands in the range of 3 GHz to 24 GHz were conducted. The LNAs adopted three kinds of configuration in this thesis. They are resistance feedback amplifier, source inductor degeneration and current reused technique. At first, a 3-10GHz low noise amplifier was designed. The adopted structure is the resistance feedback amplifier, which provides a flat gain, a good input impedance match and better stability condition for the amplifier circuit. This low noise amplifier achieves the following characteristics: gain 19.5dB~22.3dB, noise figure 6.7dB~7.7dB, input return loss -12.9dB~-14.3dB, output return loss -10.1dB~-22.5dB, and isolation -36.9dB~-39.8dB. In the second part, a Ku-band low noise amplifier was designed for the very small aperture terminal. The circuit structure is the source inductor degeneration, which provides a good input impedance match, high power transmission and low noise. This low noise amplifier achieves the following characteristics: gain 11.67dB~17.94dB, noise figure 1.454dB~2.479dB, input return loss -29.39dB~-35.44dB, output return loss -12.86dB~-20.73dB, and isolation -20.44dB~-27.99dB. Finally, a 24 GHz low noise amplifier is designed for a vehicular radar system. The structure of current reused technique was chosen which gives a high gain and low supply voltage and power consumption. Simulated data show that this low noise amplifier has a gain of 8.94dB, noise figure 2.308dB, input return loss -11.67dB, output return loss -10.93dB, and isolation -23.11dB.
Chang, Hao-Yu, та 張皓宇. "Research on room temperature terahertz emission by 0.15μm pHEMT". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/68010667024488261389.
Повний текст джерела國立交通大學
電子研究所
99
We demonstrate room-temperature terahertz emitters using 0.15 μm pHEMTs. The devices were fabricated by WIN semiconductors and were obtained through CIC. We measured emission intensities of the devices at different bias points. We also measured polarization of emission signals and emission spectra. We calibrated the emission spectra by using a black body source. We found that there are two emission peaks appearing at 10 THz and 15 THz. The total radiation power was calculated through the calibrated spectrum. The power level was estimated to be nearly one micro-watt. We propose an inter-subband transition model to explain the experimental data.
Huang, Guan-Kai, and 黃冠凱. "AlGaAs/InGaAs/GaAs pHEMT Model Parameter Extraction and Establishment." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/21995175268224445734.
Повний текст джерела國立成功大學
微電子工程研究所碩博士班
94
This thesis is to build the device models for AlGaAs/InGaAs/GaAs pHEMT. The device models include small-signal model, large-signal model, and RF noise model. In the beginning, we use the Yang-Long measurement to extract the parasitic resistance, Rs, and the cold-FET measurement to extract the other parasitic parameters of small-signal model. After extracting parasitic parameters, we de-embed those parasitic parameters to get the intrinsic circuit of pHEMT. Finally, with the Y-parameters and mathematics, we can calculate the intrinsic parameters. In the cold-FET measurements, we apply two different gate voltages to simplify the circuit. One is strong forward gate bias and the other is zero gate bias. We find that the parameters extracted from the zero gate bias are more accurate than those extracted from the forward gate bias. We adopt EEHEMT model for large-signal model in this thesis. With DC measurements and small-signal parameters, the EEHEMT model parameters can be obtained by fitting. Finally, we use ADS simulation software to verify the extracted results. As for noise model, we add two noise temperatures to the intrinsic circuit of small-signal model. The noise temperature model allows prediction of noise parameters for pHEMT devices.
Li, Wei-Nung, and 李威儂. "The Characteristic Analysis of RF Switches for GaAs pHEMT." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/57515571045022889885.
Повний текст джерела義守大學
電機工程學系碩士班
99
Due to the superior characteristics of low insertion loss, high isolation and high speed, GaAs pHEMT has been widely used to design RF switch. In this thesis, an RF switch for Quad-band cell phone was designed and fabricated. Since the switch is used for commercial system, the chip size and cost are main concerns. A three gates structure was employed to overcome the high power specification and the uneven structure of transmission path (two-section) and receiving path (one-section) was introduced to reduce the chip size. The simulation and measurement results were compared and showed a good agreement.
Chien, Jia-Fan, and 簡佳帆. "Investigation of THz radiation from pHEMT at room temperature." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/25711043394064611851.
Повний текст джерела國立交通大學
電子研究所
100
This thesis studies radiation characteristics of InGaAs/GaAs pHEMTs in THz region. We construct a system capable of measuring both angle-resolved intensity and radiation spectrum of a pHEMT under electrical excitations. Experimental results show that the intensity of a pHEMT has an angular distribution similar to cosθ. Furthermore, the in-tensity increases substantially when a pHEMT is biased from the linear region into the saturation region. The spectrum extends widely in fre-quencies from one to 18 THz and shows several peaks. We find that two of the peaks, at f = 9 and 15.5 THz, have an intensity ratio that depends on the angle and the input power, indicating the difference in their origin. By comparing the radiation spectrum with the absorption spectrum of a GaAs substrate, we infer that the peaks originate from thermal radiation of phonons. The peak at 9 THz comes from the radiation of optical pho-nons in GaAs while the peak at 15.5 THz from a combination of two phonons that are infrared active. The mechanism is further confirmed by comparing the radiation spectrum with that of a GaN/Si HEMT.
Yu, Shao-wei, and 游紹瑋. "Nonlinear Characteristics of InGaAs PHEMT with Volterra Series Analysis." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/qzv9zh.
Повний текст джерела國立中山大學
電機工程學系研究所
97
This thesis studies the nonlinear characteristics of microwave devices by Volterra series because it can analyze the nonlinear devices with memory. And a nonlinear model was established by measurement data for Volterra series analysis. This content is composed of three parts. The first part devote to introduce the nonlinear phenomenon and theories of nonlinear analysis. The difference between power series and Volterra series could be realized by deriving them. The second part is to introduce the physical characteristics of pHEMTs and demonstrate the procedure of establishing small signal model and fitting nonlinear equations of currents and capacitances, and a process of nonlinear model analysis by Volterra series is shown. The third part is to describe the experimental arrangements and analyze nonlinear characteristics of pHEMTs actually with above methods. And the relationship among nonlinear sources was discussed. The device was fabricated by WIN 0.15μm InGaAs process and measured by on wafer measurements.
Cheng-YenChen and 陳正彥. "Yield Improvement of pHEMT by Gate Photo-Resist Process Modification." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/00637607208889787073.
Повний текст джерела國立成功大學
工程科學系專班
98
GaAs semiconductor is an important component in wireless and optical fiber communications. Over 60% of GaAs’s IC chips are used in mobile power amplifiers worldwide. Hence GaAs plays an important role in mobile power amplifier components. This research uses negative PR resists for the pHEMT gate photolithography process development to make the process stable and to increase the yield. From the photolithography process principle, as negative PR resist exposure energy gets smaller, the thickness of PR becomes smaller after developing (i.e. larger PR resist thickness loss);gate ADM CD also gets larger. Besides, by changing the exposure map,the exposure throughput is increased and the locally defocusing issue of the wafer edge ugly dies is reduced. In addition, by changing the process step after exposure bake, the Gate ADM CD is greatly influenced. This study found the characteristics difference of negative PR resists affected by the process steps. By following the rules obtained for the development of new gate process, the process development speed can be reduced and the process stability can be improved.
Tseng, Min-Nan, and 曾敏男. "Epitaxial technology for the monolithic integration of HBT and PHEMT." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/98107253636103144981.
Повний текст джерела國立臺灣大學
電子工程學研究所
97
We have investigated the optimal growth conditions for integrating heterojunction bipolar transistors (HBTs) and pseudomorphic high electron mobility transistors (PHEMTs) together by metal-organic chemical vapor depositon (MOCVD). In the structure of HBT and PHEMT (BiFET), AlGaAs PHEMT is at the bottom, while InGaP HBT is on the top. The HBT and PHEMT share a heavily n-doped GaAs layer that serves as the cap of the PHEMT and the subcollector of the HBT simultaneously. A heavily n-doped InGaP layer under the HBT subcollector layer is used as an etching-stop layer for controlling the deepness of the gate recess during the PHEMT process. Through the investigation using capacitance-voltage measurement, van der Pauw measurement, high resolution secondary ion mass spectrometry, and photoluminescence and x-ray diffraction measurement, we found that the thermal cycle of InGaP HBT results in the out-diffusion of Si in the heavily doped InGaP layer and donor layer, leading to the increment in the sheet electron density and the decrement in the electron mobility, both degrading the performance of the PHEMT. After lowering the growth temperature of the HBT, Si out-diffusion is inhibited, which brings about the performance recovery of the PHEMT. Though the temperature is reduced, the DC characteristics of the HBT are still as good as those of the HBT grown at high temperature.