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Dissertations / Theses on the topic 'Microstrip circuits'
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1
Sheen, David Mark. "Numerical modeling of microstrip circuits and antennas." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13880.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1991.Includes bibliographical references (p. 231-238).
by David Mark Sheen.
Ph.D.
2
Railton, C. J. "The analysis of boxed microstrip." Thesis, University of Bath, 1987. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379056.
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Cadman, Darren Arthur. "Optically controlled photonic bandgap structures for microstrip circuits." Thesis, University of Leeds, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270745.
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Izzat, N. "Space domain analysis of inhomogeneous waveguides of the microstrip and inset guide families." Thesis, University of Bath, 1991. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292785.
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Choi, Man Soo. "Computer-aided design models for millimeter-wave suspended-substrate microstrip line." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA227259.
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Thesis (M.S. in Electrical Engineering)--Naval Postgraduate School, March 1990.Thesis Advisor(s): Atwater, H.A. Second Reader: Lee, H. M. "March 1990." Description based on signature page as viewed on August 26, 2009. DTIC Descriptor(s): Strip Transmission Lines, Computer Aided Design, Computerized Simulation, Parameters, Microwave Equipment, Radar, Full Wave Rectifiers, Transmittance, Resonant Frequency, Construction, Wave Propagation, Coefficients, Boundary Value Problems, Resonators, Circuits, Discontinuities, Ka Band, Models, Scattering, Equivalent Circuits, Frequency. Author(s) subject terms: Millimeter wave, suspended substrate, design model. Includes bibliographical references (p. 78-79). Also available online.
6
SaÌnchez-HernaÌndez, David A. "Active microstrip patch antennas for monolithic microwave integrated circuits (MMICs)." Thesis, King's College London (University of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362513.
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Hosking, Michael William. "Microstrip ring resonator at microwave frequencies : applications to superconducting and normal circuits." Thesis, University of Portsmouth, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336916.
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Solana, Gabriel A. "Modeling of Crosstalk in High Speed Planar Structure Parallel Data Buses and Suppression by Uniformly Spaced Short Circuits." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/606.
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The aim of this thesis is to identify coupling mechanisms for three line microstrip, stripline and microstrip with dielectric overlay structures as either inductive or capacitive, quantify through simulation and measurement the amount of crosstalk to be expected in terms of scattering parameters. A new method of crosstalk suppression is implemented into each three line structure by placing uniformly spaced short circuits down the length of the center transmission line.
All structures were simulated over various physical and electrical parameters. Select microstrip structures, shielded and unshielded, were fabricated and measured to validate the effectiveness of the shielding technique. Shielding effectiveness was calculated from the measurements, and their results showed that the isolation between lines was increased by up to 20dB.
9
Wang, Qingyuan. "Broadband microstrip circuits, antennas, and antenna arrays for mobile satellite communications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/NQ56848.pdf.
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Pettis, Gregory Francis. "Hertzian dipoles and microstrip circuits on arbitrarily oriented biaxially anisotropic media." Related electronic resource: Current Research at SU : database of SU dissertations, recent titles available full text, 2008. http://wwwlib.umi.com/cr/syr/main.
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Cafaro, Nicholas Giovanni Jr. "Multiwire microstrip interconnects for high-frequency integrated circuit packaging." Thesis, Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/15454.
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Singh, Sachin. "Analysis of microstrip defected ground structure filters on anisotropic substrates using HFSS /." abstract and full text PDF (free order & download UNR users only), 2005. http://0-wwwlib.umi.com.innopac.library.unr.edu/dissertations/fullcit/3209134.
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Thesis (Ph. D.)--University of Nevada, Reno, 2005."December 2005." Includes bibliographical references (leaves 213-220). Online version available on the World Wide Web. Library also has microfilm. Ann Arbor, Mich. : ProQuest Information and Learning Company, [2005]. 1 microfilm reel ; 35 mm.
13
Tan, Song. "Design of compact and dual-band microwave microstrip balun /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?ECED%202008%20TAN.
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Jin, Won Tae. "Circuit models for a millimeter-wave suspended-microstrip line discontinuity." Thesis, Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA240906.
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Thesis (M.S. in Systems Engineering (Electronic Warfare))--Naval Postgraduate School, September 1990.Thesis Advisor(s): Atwater, Harry A. Second Reader: Janaswamy, Rama. "September 1990." Description based on title screen as viewed on December 29, 2009. DTIC Identifier(s): Suspended striplines, microstrip lines, equivalent circuits, program listings, theses. Author(s) subject terms: Suspended-microstrip line, step discontinuity, equivalent circuit model, step-change. Includes bibliographical references (p. 60). Also available in print.
15
Jackson, Ronald Edward Ramadoss Ramesh. "MEMS based tunable microstrip patch antenna fabricated using printed circuit processing techniques." Auburn, Ala., 2006. http://repo.lib.auburn.edu/2006%20Summer/Theses/JACKSON_RONALD_51.pdf.
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Zong, Junyao. "Implementation of a Microstrip Square Planar N-Way Metamaterial Power Divider." Thesis, University of Canterbury. Electrical and Computer Engineering, 2008. http://hdl.handle.net/10092/1830.
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The work done in this thesis focuses on the design of a square-shaped 20-way metamaterial power divider which is fabricated in microstrip technology and operates at 1 GHz. The divider comprises 12 square-shaped left-handed unit cells and 13 square-shaped right-handed unit cells, and these unit cells have the same size and are placed in a checker-board tessellation, where the left-handed unit cells are connected only to right-handed unit cells and vice versa. The divider is based upon the infinite wavelength phenomenon in two-dimensions, and this means that the insertion phase between any two ports of the left-handed unit cell is equal, but with opposite sign, to that of the right-handed unit cell. The divider gives an equal-amplitude equal-phase power division from the central input port to the output ports which are located on a straight line on each side. Thus, it is convenient to integrate with, or interconnect to, other planar circuits in a system, such as power amplifier modules. The design concept can be extended to an N-way power divider, where N = 4n and n is an odd integer.
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Yildirim, Meltem. "Design Of Dual Polarized Wideband Microstrip Antennas." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612023/index.pdf.
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In this thesis, a wideband dual polarized microstrip antenna is designed, manufactured and measured. Slot coupled patch antenna structure is considered in order to achieve the wideband characteristic. Although rectangular shaped slot coupled patch antennas are widely used in most of the applications, their utilization in dual polarized antenna structures is not feasible due to space limitations regarding the positioning of two separate coupling slots for each polarization. For a rectangular slot, the parameter that affects the amount of coupling is the slot length. On the other hand when a H-shaped slot is considered, both the length of the center arm and the length of the side legs determine the coupling efficiency. This flexibility about the optimization parameters of the H-shaped slot makes it possible to position the two coupling slots within the boundaries of the patch antenna. Therefore, H-shaped slot coupled patch antennas are studied in this thesis. In order to investigate the effects of slot and antenna dimensions on the radiation characteristics of the antenna, a parametric study is performed by analyzing the antenna structure with a planar electromagnetic field simulation software (Ansoft Designer). By the help of the experience gained through this parametric study, a dual polarized patch antenna that can be used at the base station of a cellular system (DCS: 1710&ndash1880 MHz) is designed. Before manufacturing the antenna, dimensions of the antenna are re-tuned by considering a finite sized ground plane in the simulations. Finally, the antenna is manufactured and measured. An acceptable agreement is obtained between the measurement and the simulation results.
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Jordan, Jennifer L. "Contactless Radio Frequency Probes for High Temperature Characterization of Microwave Integrated Circuits." Case Western Reserve University School of Graduate Studies / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=case1402066531.
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Uzelac, Lawrence Stevan. "A Multiple Coupled Microstrip Transmission Line Model for High-Speed VLSI Interconnect Simulation." PDXScholar, 1991. https://pdxscholar.library.pdx.edu/open_access_etds/4526.
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A model is presented which incorporates the advantages of a mixed mode simulation to characterize transmission line behavior in multiple coupled Transmission line systems. The model is intended for use by digital circuit designers who wish to be able to obtain accurate transmission line behavior for complex digital systems for which continuous time simulation tools such as SPICE would time prohibitive. The model uses a transverse electromagnetic wave approximation to obtain solutions to the basic transmission line equations. A modal analysis technique is used to solve for the attenuation and propagation constants for the transmission lines. Modal analysis done in the frequency domain after a Fast Fourier Transform of the time-domain input signals. Boundary conditions are obtained from the Thevinized transmission line input equivalent circuit and the transmission line output load impedance. The model uses a unique solution queue system that allows n-line coupled transmission lines to be solved without resorting to large order matrix methods or the need to diagonals larger matrices using linear transformations. This solution queue system is based on the method of solution superposition. As a result, the CPU time required for the model is primarily a function of the number of transitions and not the number of lines modeled. Incorporation of the model into event driven circuit simulators such as Network C is discussed. It will be shown that the solution queue methods used in this model make it ideally suited for incorporation into a event-driven simulation network. The model presented in this thesis can be scaled to incorporate direct electromagnetic coupling between first, second, or third lines adjacent to the line transitioning. It is shown that modeling strictly adjacent line coupling is adequate for typical digital technologies. It is shown that the model accurately reproduces the transmission line behavior of systems modeled by previous authors. Example transitions on a 8-line system are reviewed. Finally, future model improvements are discussed.
20
Khoshniat, Ali. "A Linearly and Circularly Polarized Active Integrated Antenna." DigitalCommons@USU, 2011. https://digitalcommons.usu.edu/etd/881.
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This thesis work presents a new harmonic suppression technique for microstrip patch antennas. Harmonic suppression in active integrated antennas is known as an effective method to improve the efficiency of amplifiers in transmitter side. In the proposed design, the antenna works as the radiating element and, at the same time, as the tuning load for the amplifier circuit that is directly matched to the antenna. The proposed active antenna architecture is easy to fabricate and is symmetric, so it can be conveniently mass-produced and designed to have circular polarization, which is preferred in many applications such as satellite communications.
The antenna simulations were performed using Ansoft High Frequency System Simulator (HFSS) and all amplifier design steps were simulated by Advanced Design System (ADS). The final prototypes of the linearly polarized active integrated antenna and the circularly polarized active integrated antenna were fabricated using a circuit board milling machine. The antenna radiation pattern was measured inside Utah State University's anechoic chamber and the results were satisfactory. Power measurements for the amplifiers' performance were carried out inside the chamber and calculated by using the Friis transmission equation. It is seen that a significant improvement in the efficiency is achieved compared to the reference antenna without harmonic suppression.
Based on the success in the single element active antenna design, the thesis also presents a feasibility of applying the active integrated antenna in array configuration, in particular, in scanning array design to yield a low-profile, low-cost alternative to the parabolic antenna transmitter of satellite communication systems.
21
Wang, Li Kang. "Design of ultra-wideabnd [sic] bandpass filter with reconfigurable bandwidth and notch using microstrip and slotline structure." Thesis, University of Macau, 2017. http://umaclib3.umac.mo/record=b3691126.
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DiBene, II Joseph Theodore. "Analysis of complex graded-dielectric structures for dispersion compensation in high frequency signal propagation in microstrip circuits." Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2006. http://wwwlib.umi.com/cr/ucsd/fullcit?p3204583.
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Thesis (Ph. D.)--University of California, San Diego, 2006.Title from first page of PDF file (viewed April 4, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 169-174).
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Onat, Sinan. "Re-configurable Microstrip Patch Antennas Controlled By Rf Mems Switches." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607969/index.pdf.
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This thesis presents design, fabrication and testing of a number of multi-frequency
band microstrip-fed re-configurable microstrip patch antennas. All re-configurable
antennas are designed to change from one resonance frequency to another by an
electronic control of RF MEMS switches, one at a time. Besides a fixed size slot on
the patch, switches are placed in insets for satisfying better input match at each
resonance frequency individually. Also some switches are placed into the slot for
adding another resonance frequency to change the effective slot-length like
effective inset length changing.To actuate the RF MEMS switches in the configured way, DC-stubs are also
designed to apply required potential difference between switch ports and the carrier.
These stubs exhibit RF-open at switch side to prevent any RF leakage, and DCground
on the other side. That RF short-to-open conversion is accomplished
together with feed structurewith a taper depending on the feed network selected. All devices introduced here are built by Microwave Research Group in Electrical and Electronics Department, Middle East Technical University. Depending on the sensitivity of structure, some devices are built by RF MEMS group in Microelectronic Production Plant for MEMS (METU &
#8211
MET) during the thesis study. Therefore this study is the continuation of the first national work on fabrication of RF MEMS devices.
24
Schoeman, Marlize. "Mixed-potential integral equation technique for hybrid microstrip-slotline mutli-layered circuits with horizontal and vertical shielding walls." Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/16425.
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Thesis (MScIng)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: A complete mixed-potential integral equation formulation for the analysis of arbitrarily shaped scatterers in a planarly layered medium is presented. The integral equation is able to solve for simultaneous electric and magnetic surface currents using a Method of Moments (MoM) procedure. The MoM formulation which was developed uses vector-valued basis functions defined over a triangular mesh and are used to model electric currents on conducting scatterers and magnetic currents on slotline structures. The Green’s functions employed in the analysis were developed for a stratified medium using a Sommerfeld plane wave formulation. The scheme used for filling the method of moments matrix was designed to simultaneously solve multiple problems that are stacked and separated by an infinite conducting ground plane. The filling algorithm also efficiently packs partially symmetric matrices, which are present when solving problems that support a combination of electric and magnetic currents. Several examples are presented to illustrate and validate the analysis method. Numerical predictions of the scattering parameters (both magnitude and phase) show good correspondence with results from literature and measured data.
AFRIKAANSE OPSOMMING: ’n Volledige gemengde potensiaal integraalvergelyking formulering vir die analise van stralers van arbitrˆere vorm binne gelaagde strukture word aangebied. Die integraalvergelyking kan gelyktydige elektriese en magnetiese oppervlakstrome oplos deur die Metode van Momente (MoM) te gebruik. Die MoM formulering gebruik vektor basis funksies wat oor ’n driehoekige diskretisering gedefinieer word om elektriese strome op geleidende stralers en magnetiese strome op gleuflyn strukture te modelleer. Die Green’s funksies wat in die analise gebruik word, is ontwikkel vir gelaagde media deur gebruik te maak van Sommerfeld se platvlakgolf formulering. Die metode wat gebruik word om the moment matriks te vul, is ontwerp om meervoudige gestapelde probleme wat deur oneindig geleidende grondvlakke geskei word, gelyktydig op te los. Gedeeltelik simmetriese matrikse word ook effektief gevul. Hierdie matrikse kom voor wanneer probleme ’n kombinasie van elektriese en magnetiese strome ondersteun. Verskeie voorbeelde word gebruik om die analise metode te verifieer. Numeriese voorspellings van strooiparameters (beide grootte en hoek) vergelyk baie goed met resultate en gemete data wat in die literatuur gevind is. iv
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Lemtiri, Chlieh Outmane. "Development of microfluidic packages on multilayer organic substrate for cooling and tuning RF circuits." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54376.
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The objective of this PhD research was to design and implement novel microfluidic radio-frequency (RF) structures on multilayer organic substrates for cooling and tuning purposes. The different designs were implemented to target applications up to C-band (4 GHz – 8 GHz) frequencies. The system-on-package (SoP) solution adopted throughout this work is well adapted for such designs where there is a need to integrate the functionality of different sub-components into a single hybrid fully packaged system. The first part of the thesis is dedicated to the study of a specific liquid cooling scheme using integrated microchannels on organics placed beneath different types of heat sources. A 1 W gallium nitride (GaN) die was cooled using this method and an analysis is presented regarding the cases where the coolant is static or dynamic inside the microchannel. The second part of the thesis deals with microfluidically reconfigurable microstrip RF circuits, mainly bandpass filters and power amplifiers (PAs). The microfluidic tuning technique is based on the change in the effective dielectric constant that the RF signal “sees” when traveling above two microchannels with different fluids. This technique was used to shift the frequency response of an L-band microstrip bandpass filter by replacing DI water with acetone inside a 60 mil micro-machined cavity. This technique was also used to design reconfigurable matching networks which constitute the main part of the proposed tunable GaN-based PA for S- and C-band applications. The final part of the thesis expands the previous results by combining both cooling and tuning in a single RF design. To prove the concept, cooling and tuning microchannels were integrated into a single package to cool a GaN-based PA and tune its frequency response at the same time from 2.4 GHz to 5.8 GHz and vice versa.
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U-yen, Kongpop. "Microwave filters with high stop-band performance and low-loss hybrid developement." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-11162006-111102/.
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Thesis (Ph. D.)--Electrical and Computer Engineering, Georgia Institute of Technology, 2007.Tentzeris, Manos, Committee Member ; Wollack, Edward, Committee Member ; Cressler, John, Committee Member ; Papapolymerou, Ioannis, Committee Chair ; Laskar, Joy, Committee Co-Chair ; Ayazi, Farrokh, Committee Member.
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Müller-Bierl, Bernd Michael. "Rayonnement et couplage entre les interconnexions dans les circuits hyperfréquences : étude au moyen de la méthode tlm." Grenoble INPG, 1997. http://www.theses.fr/1997INPG0026.
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La these est constitue de 3 parties principales. Apres une introduction a l'analyse des lignes micro-ruban sous approximation de propagation des signaux en mode tem, la premiere partie traite d'une methode d'anaulyse dynamique valable pour des distributions de champs qui peuvent meme etre eloignees du mode tem, la methode tlm (transmission line matrix method), introduite 1971 par johns et al. La methode tlm est presentee comme un processus de repartition base sur la decomposition des equations de maxwell sous forme matricielle. Dans une deuxieme partie nous traitons de la possibilite d'utiliser la methode tlm dans les problemes dits de l'espace ouvert, c'est a dire des espaces de calcul limites par des parois absorbant toute l'energie quittant le domaine de calcul. Cela est necessaire afin de reduire l'espace memoire necessaire pour calculer par example des effets de rayonnement et de diffraction. Dans la troisieme partie nous appliquons la methode tlm pour calculer les parametres des differents discontinuites micro-ruban, en particulier les effets de couplage et de rayonnement. Au moyen d'une transformation des champs proches en champs lointain nous determinons egalement les diagrammes de rayonnement correspondants. L'ensemble du travail se situe dans le cadre des problemes de compatibilite electromagnetique.
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Donado, Morcillo Carlos Alberto. "Development of lightweight and low-cost microwave components for remote-sensing applications." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/51733.
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The objective of the proposed research is to design, implement, and characterize low-cost, lightweight front-end components and subsystems in the microwave domain through innovative packaging architectures for remote sensing applications. Particular emphasis is placed on system-on-package (SoP) solutions implemented in organic substrates as a low-cost alternative to conventional, expensive, rigid, and fragile radio- frequency substrates. To this end, the dielectric properties of organic substrates RT/duroid 5880, 6002 and 6202 are presented from 30 GHz to 70 GHz, covering most of the Ka and V radar bands, giving also a thorough insight on the uncertainty of the microstrip ring resonator method by means of the Monte Carlo uncertainty analysis. Additionally, an ultra-thin, high-power antenna-array technology, with transmit/ receive (T/R) functionality is introduced for mobile applications in the X band. Two lightweight SoP T/R array panels are presented in this work using novel technologies such as Silicon Germanium integrated circuits and microelectromechanical system switches on a hybrid organic package of liquid crystal polymer and RT/duroid 5880LZ. A maximum power of 47 dBm is achieved in a package with a thickness of 1.8 mm without the need of bulky thermal management devices. Finally, to address the thermal limitations of thin-film substrates of interest (liquid crystal polymer, RT/duroid 6002, alumina and Aluminum Nitride), a thermal assessment of microstrip structures is presented in the X band, along with the thermal characterization of the dielectric properties of RT/duroid 6002 from 20 ºC to 200 ºC and from 30 GHz to 70 GHz. Additional high-power, X-band technologies presented in this work include: a novel and compact topology for evanescent mode filters, and low-profile Wilkinson power dividers implemented on Aluminum Nitride using Tantalum Nitride thin-film resistors.
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El-Rabaie, E. S. M. "Microwave GaAs FET circuit design." Thesis, Queen's University Belfast, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234136.
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Costa, Iradilson Ferreira da. "Antenas e superf?cies seletivas de freq??ncia reconfigur?veis para sistemas de comunica??o sem fio." Universidade Federal do Rio Grande do Norte, 2009. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15286.
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Previous issue date: 2009-08-11Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
This work aims to present how the reconfigurable microstrip antennas and frequency selective surfaces can be used to operate at communication systems that require changing their operation frequency according to system requirements or environmental conditions. The main purpose is to present a reconfigurable circular microstrip antenna using a parasitic ring and a reconfigurable dipole frequency selective surface. Thereupon there are shown fundamental topics like microstrip antennas, PIN diodes and the fundamental theory of reconfigurable antennas and frequency selective surfaces. There are shown the simulations and measurements of the fabricated prototypes and it is done an analysis of some parameters like the bandwidth and radiation pattern, for the antennas, and the transmission characteristics, for the frequency selective surface. Copper strips were used in place of the diodes for proof of the reconfigurability concept
Este trabalho tem como objetivo apresentar como as antenas de microfita e as superf?cies seletivas de frequ?ncia reconfigur?veis podem ser alternativas para operar em sistemas de comunica??o sem fio que necessitem alterar sua frequ?ncia de opera??o de acordo com os requisitos impostos a este sistema ou condi??es do meio. O prop?sito central ? apresentar uma antena de microfita com patch circular reconfigur?vel utilizando um anel parasita e uma superf?cie seletiva de frequ?ncia tipo dipolo reconfigur?vel. Para isto s?o apresentados temas fundamentais como as antenas de microfita, diodos PIN e a teoria fundamental de opera??o das antenas e superf?cies seletivas de frequ?ncia reconfigur?veis. S?o apresentadas todas as simula??es e medi??es realizadas dos prot?tipos constru?dos e ? feita uma an?lise de alguns par?metros como largura de banda e diagrama de radia??o, para as antenas, e caracter?sticas de transmiss?o, para as superf?cies seletivas de frequ?ncia. Foram utilizadas fitas de cobre no lugar dos diodos para a prova do conceito de reconfigurabilidade
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Donado, Morcillo Carlos Alberto. "Development of lightweight and low-cost microwave components for remote-sensing applications." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47532.
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The objective of the proposed research is to design, implement, and characterize low-cost, lightweight front-end components and subsystems in the microwave domain through innovative packaging architectures for remote sensing applications. Particular emphasis is placed on system-on-package (SoP) solutions implemented in organic substrates as a low-cost alternative to conventional, expensive, rigid, and fragile radio- frequency substrates. To this end, the dielectric properties of organic substrates RT/duroid 5880, 6002 and 6202 are presented from 30 GHz to 70 GHz, covering most of the Ka and V radar bands, giving also a thorough insight on the uncertainty of the microstrip ring resonator method by means of the Monte Carlo uncertainty analysis.
Additionally, an ultra-thin, high-power antenna-array technology, with transmit/ receive (T/R) functionality is introduced for mobile applications in the X band. Two lightweight SoP T/R array panels are presented in this work using novel technologies such as Silicon Germanium integrated circuits and microelectromechanical system switches on a hybrid organic package of liquid crystal polymer and RT/duroid 5880LZ. A maximum power of 47 dBm is achieved in a package with a thickness of 1.8 mm without the need of bulky thermal management devices.
Finally, to address the thermal limitations of thin-film substrates of interest (liquid crystal polymer, RT/duroid 6002, alumina and Aluminum Nitride), a thermal assessment of microstrip structures is presented in the X band, along with the thermal characterization of the dielectric properties of RT/duroid 6002 from 20 C to 200 C and from 30 GHz to 70 GHz. Additional high-power, X-band technologies presented in this work include: a novel and compact topology for evanescent mode filters, and low-profile Wilkinson power dividers implemented on Aluminum Nitride using Tantalum Nitride thin-film resistors.
32
Belentepe, Bilge. "Electromagnetically coupled microstrip patch antenna array design." Thesis, University of Surrey, 1993. http://epubs.surrey.ac.uk/842825/.
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This work is an effort to investigate and derive a simple equivalent circuit model to represent an electromagnetically coupled microstrip patch antenna. This provides a simple approach to the complicated electromagnetic coupling behaviour in the patch. A simplified theory based on the broadside coupled line and improved transmission line theories is developed to derive the equivalent circuit of EM coupled patch antenna. The design parameters are determined from the above mentioned theory. Computer programs are developed to provide a practical design of such antennas without involving complicated, time consuming, rigorous methods. A number of sample patches are designed, made and tested to verify the theory. These elements are also incorporated into an array to evaluate their performance in an array environment. The impedance and pattern measurements are made for comparison with theoretical results.
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Silva, Neto Valdemir Praxedes da. "Caracteriza??o de circuitos planares de micro-ondas pelo m?todo iterativo das ondas." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15480.
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Previous issue date: 2013-07-26The planar circuits are structures that increasingly attracting the attention of researchers, due the good performance and capacity to integrate with other devices, in the prototyping of systems for transmitting and receiving signals in the microwave range. In this context, the study and development of new techniques for analysis of these devices have significantly contributed in the design of structures with excellent performance and high reliability. In this work, the full-wave method based on the concept of electromagnetic waves and the principle of reflection and transmission of waves at an interface, Wave Concept Iterative Procedure (WCIP), or iterative method of waves is described as a tool with high precision study microwave planar circuits. The proposed method is applied to the characterization of planar filters, microstrip antennas and frequency selective surfaces. Prototype devices were built and the experimental results confirmed the proposed mathematical model. The results were also compared with simulated results by Ansoft HFSS, observing a good agreement between them.
Os circuitos planares s?o estruturas que atraem cada vez mais a aten??o dos pesquisadores, pelo bom desempenho e pela capacidade de integra??o com outros dispositivos, na prototipagem de sistemas de transmiss?o e recep??o de sinais na faixa de micro-ondas. Neste contexto, o estudo e o desenvolvimento de novas t?cnicas de an?lise desses dispositivos t?m contribu?do de forma significativa na concep??o de estruturas com desempenhos excelentes e alto grau de confiabilidade. Neste trabalho, o m?todo de onda completa baseado no conceito de ondas eletromagn?ticas e no princ?pio da reflex?o e transmiss?o de ondas em uma interface, Wave Concept Iterative Procedure (WCIP), ou m?todo iterativo das ondas ? descrito como uma ferramenta com alto grau de precis?o no estudo de circuitos planares de micro-ondas. O m?todo proposto ? aplicado na caracteriza??o de filtros planares, antenas de microfita e superf?cies seletivas de frequ?ncia. Prot?tipos dos dispositivos foram constru?dos e os resultados experimentais comprovaram o modelo matem?tico proposto. Os resultados obtidos tamb?m foram comparados com os resultados simulados pelo Ansoft HFSS, tendo sido observada uma boa concord?ncia entre eles
34
Kalialakis, Christos. "Finite difference time domain analysis of microstrip antenna-circuit modules." Thesis, University of Birmingham, 1999. http://etheses.bham.ac.uk//id/eprint/65/.
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Compact microstrip antenna-circuit modules, which could be used as front-ends for future wireless systems applications, require electromagnetic modelling due to the close interaction of the circuit with the antenna. Spectrum crowding and EMC/EMI issues call for modelling of the radiation of such modules. Coupling through fringing fields and the nonlinearities of active devices must be addressed. In this work, the FDTD method was used because it can provide the framework for inclusion of circuit elements in a full wave calculation. A software tool was developed and validated based on this method. The modules studied were chosen due to their compactness and their merit as system components. A module with simultaneous transmit-receive operation integrating an active circulator (using amplifiers in a ring-like arrangement) and a quarter wavelength antenna was analysed. Coupling effects were identified and their impact on the radiation patterns was shown. Electronically tuneable microstrip patch antennas using varactor diodes were also studied. Tuning range and harmonic radiation were demonstrated. Single and dual device Gunn oscillator antennas were analysed and their radiation patterns were calculated for the first time. All of our results were in agreement with experimental findings.
35
Ozkal, Piroglu Sefika. "Analysis Of Coupled Lines In Microwave Printed Circuit Elements." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/2/12609047/index.pdf.
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Full wave analysis of microstrip lines at microwave frequencies is performed by using method of moments in conjunction with closed-form spatial domain Green&rsquos functions. The Green&rsquo
s functions are in general Sommerfeld-type integrals which are computationally expensive. To improve the efficiency of the technique, Green&rsquo
s functions are approximated by their closed-forms. Microstrip lines are excited by arbitrarily located current sources and are terminated by complex loads at both ends. Current distributions over microstrip lines are represented by rooftop basis functions. At first step, the current distribution over a single microstrip line is calculated. Next, the calculation of the current distributions over coupled microstrip lines is performed. The technique is then, applied to directional couplers. Using the current distributions obtained by the analysis, the scattering parameters of the structures are evaluated by using Prony&rsquo
s method. The results are compared with the ones gathered by using simulation software tools, CNL/2&trade
and Agilent Advanced Design System&trade
(ADS).
36
Crouch, David Andrew. "Gallium arsenide field effect transistors microstrip integrated circuit dielectric resonator oscillators." Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/8329.
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Bibliography: leaves 175-177.This thesis is concerned with Gallium Arsenide Metal Semiconductor Field Effect Transistor Microstrip Integrated Circuit Dielectric Resonator Oscillators (GaAs MESFET MIC DROs) - the different types, their design and their performance compared to other high Q factor (ie narrowband) microwave oscillators. The thesis has three major objectives. The first is to collate the information required to build microwave DROs. The second is to present the practical results obtained from Dielectric Resonator Bandreject and Bandpass filters (DR BRFs and DR BPFs). The last is to present and compare results from a DR stabilised microstrip oscillator and three types of series feedback DROs. Narrowband oscillators are usually evaluated in terms of their frequency stability, reliability, size, cost, efficiency and output power characteristics. In terms of these parameters DROs outperform Gunn cavity oscillators and are only bettered by crystal locked sources in terms of frequency temperature stability and long-term stability. The components of a GaAs MESFET MIC DRO possess ideal properties for the construction of a narrowband source with the exception of the long term stability of the GaAs MESFET. GaAs MESFET•DROs have the best published DRO results for efficiency, output power, power temperature stability and external Q factor. Basic oscillator theory derived by Kurokawa can be applied to both negative resistance and feedback oscillators. Impedance locus, device-line and operating point concepts provide a convenient framework for understanding hysteresis in microwave oscillators. The work by Kurokawa can also be translated into the S-parameter domain which has proved convenient for the design of microwave oscillators.
37
Page, Michael John. "The analysis and design of n-port microstrip planar disk devices." Thesis, University of Hull, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333767.
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Iseri, Kadir. "Analysis Of Dual-polarized Aperture-coupled Microstrip Antennas With H-shaped Slots And Equivalent Circuit Modeling Of H-shaped Slots." Master's thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614527/index.pdf.
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This thesis includes the design, production and measurement of a wideband dualpolarized
X-band aperture-coupled microstrip patch antenna. The wideband and
dual-polarized operation is achieved through the use of H-shaped coupling slots.
Therefore, the equivalent circuit modeling of a microstrip line fed H-shaped slot is
also studied in this thesis. A step-by-step procedure is followed during the design
process of the dual-polarized aperture-coupled microstrip antenna. First, an
aperture-coupled microstrip antenna with a single rectangular slot, that exhibits a
wideband characteristic for single polarization, is designed. Then, the design
procedure is repeated for an antenna with H-shaped slot in order to satisfy the same
specifications with a shorter slot. Finally, dual-polarized aperture-coupled
microstrip antenna is designed. At this configuration, two H-shaped slots are used
and they are placed orthogonal to each other. During the design process, the effects
of antenna parameters on the input impedance characteristics of the antenna are
investigated. These parametric analyses are done in CST Microwave Studio®. The v designed dual-polarized wideband aperture-coupled microstrip antenna is manufactured. Simulation results and measurement results are compared. During the equivalent circuit modeling of an H-shaped slot fed by a microstrip line, an approach based on the reciprocity theorem is utilized. The method was originally proposed for rectangular shaped slots, in this thesis it is generalized for arbitrarily shaped slots. Software codes are developed in MATLAB to calculate the equivalent impedance of the slot.
39
Pajares, Vega Francisco Javier. "Modelatge multimodal de transicions en entorn microstrip." Doctoral thesis, Universitat Ramon Llull, 2007. http://hdl.handle.net/10803/9134.
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Avui dia cada vegada s'ha de tenir més en compte com es realitza el traçat de pistes en les plaques de circuit imprès (PCB). Això és degut a que cada vegada més hi viatgen senyals amb components freqüencials més elevades. Per tant, paràmetres com la desadaptació per impedància característica, acoblaments, ressonàncies i comportaments complexes de les transicions que es troben els senyals en la seva propagació per les pistes, han de ser considerats per evitar problemes d'integritat del senyal i garantir la compatibilitat electromagnètica (EMC) amb el seu entorn. El present treball de tesi s'ha centrat en l'estudi del comportament d'una situació particular, però molt habitual, de pistes: dues pistes sobre un pla de massa, formant el que es coneix com una línia de transmissió microstrip acoblada. Els senyals que viatgen a través d'una línia microstrip acoblada es poden descompondre en dos modes bàsics de propagació: mode comú (on la tensió està definida entre el pla de massa i cada pista) i el mode diferencial (on la tensió està definida entre les pistes). Aquesta descomposició és molt habitual en el món de la compatibilitat electromagnètica ja que les tècniques de filtratge de les interferències varien depenent si aquestes viatgen en mode comú o en mode diferencial.
El treball desenvolupat s'ha focalitzat en l'estudi, des d'aquest punt de vista multimodal (que té en compte simultàniament tant el mode comú com el diferencial), de les diferents transicions que es pot trobar el senyal en la seva propagació degut al traçat de pistes. Com a resultat d'aquest estudi s'han obtingut uns models circuitals que permeten l'anàlisi i simulació dels diferents modes que intervenen i que han estat validats de forma experimental. Aquest fet ha permès l'ús d'aquests models en l'anàlisi de problemes d'integritat del senyal que són comuns en el entorn de la compatibilitat electromagnètica (EMC). Els resultats obtinguts han estat presentats en congressos nacionals i internacionals.
Hoy en día cada vez se debe tener más en cuenta como se realiza el trazado de pistas en las placas de circuito impreso (PCB). Esto es así debido a que cada vez más viajan por ellas señales con componentes frecuenciales más elevadas. Por lo tanto, parámetros como la desadaptación por impedancia característica, acoplamientos, resonancias y comportamientos complejos de las transiciones que se encuentran las señales mientras se propagan por las pistas, deben ser tenidos en consideración para evitar problemas de integridad de la señal y garantizar la compatibilidad electromagnética (EMC) con su entorno.
En el presente trabajo de tesis se ha centrado en el estudio del comportamiento de una situación particular, pero habitual, de pistas: dos pistas sobre un plano de masa, formando lo que se conoce como línea de transmisión microstrip acoplada. Las señales que viajan a través de una línea microstrip acoplada se pueden descomponer en dos modos básicos de propagación: modo común (donde la tensión está definida entre el plano de masa y cada pista) y modo diferencial (donde la tensión está definida entre pistas). Esta descomposición es muy habitual en el mundo de la compatibilidad electromagnética ya que las técnicas de filtrado de las interferencias varían dependiendo si estas viajan en modo común o en modo diferencial.
El trabajo desarrollado se ha focalizado en el estudio, desde este punto de vista multimodal (que tiene en cuenta simultáneamente tanto el modo común como el diferencial), de las diferentes transiciones que puede encontrarse la señal durante su propagación debido al trazado de pistas. Como resultado se han obtenido unos modelos circuitales que permiten el análisis y simulación de los diferentes modos que intervienen y que han sido validados de forma experimental. Este hecho ha permitido el uso de dichos modelos en el análisis de problemas de integridad de la señal que son comunes en el entorno de la compatibilidad electromagnética (EMC). Los resultados obtenidos han sido mostrados en congresos nacionales e internacionales.
Nowadays, the placement of the strips in a printed circuit board (PCB) has to be performed with increasing care, because of the rise of the spectral content of the signals propagating through the strips. Due to this fact, mismatches of the characteristic impedances, crosstalks, resonances and complex behavior of the transitions that the signals may encounter in their propagation have to be considered in order to avoid signal integrity problems and to guarantee the electromagnetic compatibility with their environment.
This work is focused on the study of the behavior of a particular, but also a very common way of routing strips: two close strips above a ground plane, forming a extit{coupled microstrip transmission line}. The signals present at this transmission line can be decomposed into two basic signals known as common mode (where its voltage is defined between the ground plane and each strip) and differential mode (where its voltage is defined between the two strips). This decomposition is often found in electromagnetic compatibility because the different techniques of filtering interferences depend on their main mode of propagation.
The study carried out in this thesis is focused on the analysis from a multimodal point of view of different transitions that signals encounter during their propagation in a coupled microstrip transmission line.
As a result of this analysis, a number of circuit models for different transitions have been obtained and experimentally validated. These models have been used to successfully study signal integrity problems found in EMC and they have been presented in national and international symposiums.
40
Feyzbakhsh, Homayun. "Development of a library of neural models for microstrip line components for high-frequency circuit design." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0027/MQ52389.pdf.
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Feyzbakhsh, Homayun Carleton University Dissertation Engineering Electronics. "Development of a library of neural models for microstrip line components for high frequency circuit design." Ottawa, 1999.
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Alibakhshikenari, M., B. S. Virdee, P. Shukla, Y. Wang, L. Azpilicueta, M. Naser-Moghadasi, Chan H. See, et al. "Impedance Bandwidth Improvement of a Planar Antenna Based on Metamaterial-Inspired T-Matching Network." IEEE, 2021. http://hdl.handle.net/10454/18486.
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yesIn this paper a metamaterial-inspired T-matching network is directly imbedded inside the feedline of a microstrip antenna to realize optimum power transfer between the front-end of an RF wireless transceiver and the antenna. The proposed T-matching network, which is composed of an arrangement of series capacitor, shunt inductor, series capacitor, exhibits left-handed metamaterial characteristics. The matching network is first theoretically modelled to gain insight of its limitations. It was then implemented directly in the 50-Ω feedline to a standard circular patch antenna, which is an unconventional methodology. The antenna’s performance was verified through measurements. With the proposed technique there is 2.7 dBi improvement in the antenna’s radiation gain and 12% increase in the efficiency at the center frequency, and this is achieved over a significantly wider frequency range by a factor of approximately twenty. Moreover, there is good correlation between the theoretical model, method of moments simulation, and the measurement results.
43
Papageorgiou, Vassilios A. "Static two-dimensional calculation of the capacitance and impedance of open microstrip-like structures using variational methods." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08182009-040513/.
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Mustafa, Incebacak. "Design Of Series-fed Printed Slot Antenna Arrays Excited By Microstrip Lines." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12612447/index.pdf.
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Series-fed printed slot antenna arrays excited by microstrip lines are low profile, easy to manufacture, low cost structures that found use in applications that doesn&rsquot require high power levels with having advantage of easy integration with microwave front-end circuitry. In this thesis, design and analysis of microstrip line fed slot antenna arrays are investigated. First an equivalent circuit model that ignores mutual coupling effects between slots is studied. A 6-element array is designed by using this equivalent circuit model. From the measurement and electromagnetic simulation results of this array, it is concluded that mutual coupling effects should be considered in order to achieve a successful design that meets the design specifications related to the main beam direction and sidelobe levels of the antenna. Next, an improved equivalent circuit model proposed for stripline fed slot antenna arrays is studied. It is observed that, the mutual coupling effects are incorporated into the equivalent model through the utilization of active impedance concept. Finally, the design equations proposed in the improved equivalent circuit model are derived for the microstrip line fed slot antenna array structure. To demonstrate the validity and the accuracy of the derived design equations, results obtained by the proposed analysis method are compared with simulation and measurement results. It is concluded that the proposed method successfully predicts the radiation pattern of the array by including the mutual coupling effects.
45
Quémerais, Thomas. "Conception et étude de la fiabilité des amplificateurs de puissance fonctionnant aux fréquences millimétriques en technologies CMOS avancées." Grenoble INPG, 2010. http://www.theses.fr/2010INPG0158.
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Avec l'émergence d'applications millimétriques telles que le radar automobile ou le WHDMI, la fiabilité est devenue un enjeu extrêmement important pour l'industrie. Dans un émetteur/récepteur radio, les problèmes de fiabilité concernent principalement les transistors MOS intégrés dans les amplificateurs de puissance, compte-tenu des niveaux relativement élevés des puissances. Ces composants sont susceptibles de se détériorer fortement par le phénomène de l'injection de porteurs chauds impactant lourdement les performances des amplificateurs. Ce travail de thèse concerne la conception et l'étude de la fiabilité des amplificateurs de puissance fonctionnant aux fréquences millimétriques en technologies CMOS avancées. Le mémoire est articulé autour de quatre chapitres. Les deux premiers chapitres concernent l'étude, la conception, la modélisation et la caractérisation des éléments actifs et passifs intégrés sur silicium et utilisés pour réaliser des amplificateurs de puissance aux fréquences millimétriques. Le troisième chapitre décrit les trois amplificateurs de puissance conçus et réalisés pour les tests de fiabilité. Enfin, le dernier chapitre propose une étude complète de la fiabilité de ces circuits jusqu'au calcul de leur temps de vieWith the emergence of millimeter-wave applications such as automotive radar or WHDMI, the reliability became a very important issue for the industry. In a radio transceiver, the main reliability problems concern the MOS transistors used in the power amplifiers, due to the high power level. These devices are subject to deterioration by the hot carrier phenomenon. This impacts heavily the power amplifiers performances. This thesis work concerns the design and the study of the reliability of millimeter-wave power amplifiers in advanced CMOS technologies. The manuscript is divided into four chapters. The two first one concern the study, the design, the modeling and the characterization of integrated active and passive elements on silicon and used into power amplifiers at millimeter wave frequencies. The third chapter describes the three power amplifiers designed and realized for reliability tests. The final chapter provides a comprehensive study of the reliability of these circuits to calculate their lifetime
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Emond, Julien. "Contribution à l'étude des structures passives verre-silicium dans le domaine millimétrique." Phd thesis, Université Paris-Est, 2010. http://tel.archives-ouvertes.fr/tel-00600678.
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Nous proposons dans cette thèse de nouvelles structures à faibles pertes en vue de leur utilisation dans les bandes millimétriques. L'hypothèse forte sur laquelle es t construite notre étude est que la présence du silicium permet d'envisager une intégration plus facile des circuits. Pour ce faire nous avons étudié les caractéristiques électriques des lignes inversées silicium-verre à 60 GHz ainsi que la ligne de Goubau sur silicium aux mêmes fréquences. Nous nous sommes focalisés sur l'étude des pertes des lignes. Les simulations présentées jusqu'à 60 GHz ont montré que les qualités de la technologie verre-silicium sont bonnes en termes de paramètres hyperfréquences. Nous proposons donc d'utiliser plutôt le verre pour la partie passive et le silicium pour la partie active. Nous montrons ainsi que cette technologie admet la réalisation des fonctions diverses et qu'elle est susceptible de permettre l'obtention de systèmes intégrés
47
Kokolia, Martin. "Nositelná rektifikační anténa pro RF sklízení energie." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-241041.
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The aim of this thesis is to design and rectena that would be able to integrate into a cloth thanks to use of textile substrate. The first part deals with the possibilities of using various communication channels and services for maximizing the useable power. Attention is focused mainly on the use of textile materials for implementing microstrip circuits. It is made valorization of all the typical characteristics and problems using different fabrics as a microwave substrate and the possibilities of realization of conductive structures of microwave patch antenna and microstrip circuits. At the second part are identified parameters and constraints used for the design of the overall device with a rectifying antenna, which will be after the verification of the function in real implementation used for the final concept using textile structures. The design is verified by simulations by CST Microwave Studio and Microwave Designer. The initial design is being gradually extended by other concepts, the use of other materials and technologies. Several design are made, their properties evaluated and the best ones are then compared based on real measurements.
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Parrow, Jacob Matthew. "Equivalent Circuit Modeling and Signal Integrity Analysis of Magneto-Static Responsive Structures, and Their Applications in Changing The Effective Permittivity of Microstrip Transmission Lines." Thesis, North Dakota State University, 2016. https://hdl.handle.net/10365/28002.
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This work presents the equivalent circuit model, ringing and overshoot characteristics, as
well as the ability of a new magneto-static responsive structure (MRS) to achieve the recon gurabil-
ity of a variable e ective permittivity structure (VEPS). Through the use of a static magnetic eld
and micro-sized conductive magnetic particles, the MRS can be used to connect separate transmis-
sion lines (TL) that operate up to a radio frequency of 5 GHz. The simulated and measured results
show the MRS functions well compared to other switching methods. The VEPS's ability to achieve
e ective permittivity recon gurability is also demonstrated, showing that the VEPS functions as
the well-known mushroom structure when the MRSs are in the on state and as a regular TL when
the MRSs are in the o state. Finally, several brief studies of the MRS are performed, including the
activation methods, MRS geometry, di erent types of magnetic particles, and smaller embedded
MRSs within the VEPS.
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CHEN, YI-YUAN. "I : approche spectrale des modes rayonnants dans une ligne microfente. ii: traitement electromagnetique du pseudo court-circuit microfente." Rennes, INSA, 1988. http://www.theses.fr/1988ISAR0002.
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L'objet de cette these est de decrire les caracteristiques des modes continus et discrets de la ligne microfente et de la couche dielectrique avec plan de masse. La source des modes continus est une onde plane tridimentionnelle. On presente la relation liant le spectre de fourier au spectre angulaire de l'ordre plane. Le flux de puissance est calcule pour les 2 nodes. On verifie la relation d'orthogonalite entre modes pour les cas degenere et non degenere. On presente l'analyse modale du court-circuit de la ligne a fente et les equations integrales couplees resultantes sont traites numeriquement. Un modele en cavite est egalement developpe pour resoudre le probleme de discontinuite et pour valider les resultats precedents
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Braga, Paulo Farias. "Desenvolvimento de antenas de microfita com aberturas nos patches condutores atrav?s do m?todo da segmenta??o." Universidade Federal do Rio Grande do Norte, 2005. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15401.
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Microstrip antennas are widely used in modern telecommunication systems. This is particularly due to the great variety of geometries and because they are easily built and integrated to other high frequency devices and circuits. This work presents a study of the properties of the microstrip antenna with an aperture impressed in the conducting patch. Besides, the analysis is performed for isotropic and anisotropic dielectric substrates. The Multiport Network Model MNM is used in combination with the Segmentation Method and the Greens function technique in the analysis of the considered microstrip antenna geometries. The numerical analysis is performed by using the boundary value problem solution, by considering separately the impedance matrix of the structure segments. The analysis for the complete structure is implemented by choosing properly the number and location of the neighboor element ports. The numerial analysis is performed for the following antenna geometries: resonant cavity, microstrip rectangular patch antenna, and microstrip rectangular patch antenna with aperture. The analysis is firstly developed for microstrip antennas on isotropic substrates, and then extended to the case of microstrip antennas on anisotropic substrates by using a Mapping Method. The experimental work is described and related to the development of several prototypes of rectangular microstrip patch antennas wtih and without rectangular apertures. A good agreement was observed between the simulated and measured results. Thereafter, a good agreement was also observed between the results of this work and those shown in literature for microstrip antennas on isotropic substrates. Furthermore, results are proposed for rectangular microstrip patch antennas wtih rectangular apertures in the conducting patch
As antenas de microfita s?o estruturas muito utilizadas nos sistemas de telecomunica??es atuais. Isto decorre, principalmente, da diversidade de configura??es e da facilidade de constru??o e integra??o dessas antenas com outros dispositivos e circuitos de altas freq??ncias. Neste trabalho, o m?todo de an?lise empregado ? o Modelo de Circuito de M?lti-Porta (Multiport Network Model MNM), que combinado com o M?todo da Segmenta??o e a t?cnica da Fun??o de Green, mostra-se adequado ao estudo da antena de microfita com abertura no patch condutor. A partir do equacionamento do problema do valor de contorno, ? ent?o realizada uma an?lise num?rica que consiste em avaliar a estrutura da antena considerada a partir da integra??o dos elementos em que ela foi dividida. Nessa an?lise, os elementos s?o representados por matrizes de imped?ncia e a integra??o ? implementada atrav?s de portas de circuitos adequadamente escolhidas em n?mero e posicionamento. Na an?lise num?rica, foram consideradas as seguintes estruturas: a cavidade ressonante, a microfita com patch retangular convencional (sem abertura) e a microfita com patch retangular com abertura. A an?lise foi efetuada para substratos isotr?picos e estendida para o caso de antenas com substratos anisotr?picos uniaxiais atrav?s do M?todo do Mapeamento. S?o apresentados resultados para a freq??ncia de resson?ncia e para a imped?ncia de entrada de antenas de microfita. A parte experimental do trabalho consistiu no projeto, constru??o e medi??o de v?rios prot?tipos de antenas de microfita com patches retangulares com e sem abertura. Observou-se que os resultados obtidos, atrav?s da simula??o num?rica, apresentaram uma boa concord?ncia com os das medi??es efetuadas. Os resultados deste trabalho, tamb?m, concordaram com os resultados de outros autores, dispon?veis na literatura