Dissertations / Theses: 'Filters'

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Kamoun, Leila. "Etude de filtres MMIC hyperfréquences en technologies GaN et AsGa." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0265/document.

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Ces travaux de thèse portent sur l‟étude de filtres « multi-fonctions » dont l‟objectif serait de réduire les dimensions des circuits réalisant les fonctions de filtrage dans les systèmes aéroportés. Ces travaux ont donc conduit à la réalisation de filtres large bande (2 – 18 GHz) réjecteurs développés en technologie MMIC utilisant la filière GaN, ainsi que des filtres large bande développés suivant la filière AsGa en technologie MMIC. Les différents filtres réjecteurs ont été conçus suivant deux principes :- Le premier basé sur une structure à résonateurs à lignes couplées. Les différents prototypes réalisés ont permis de montrer l‟accordabilité en fréquence grâce à une charge variable placée à l‟extrémité non court-circuité de la ligne couplée. Celle-ci peut être réalisée par une diode varactor ou par un transistor froid. Ces prototypes ont également permis de montrer la possibilité de fonctionner suivant un mode passe-tout ou un mode réjecteur par simple polarisation de transistors chargés à l‟extrémité de la ligne couplée.- Le second est basé sur l‟accordabilité de filtres actifs par commutation entre plusieurs canaux à l‟aide d‟une structure distribuée. Un prototype a été développé et réalisé en technologie AsGa. Cette structure permet à la fois une accordabilité en fréquences, ainsi qu‟en largeur de bande passante (par activation de plusieurs canaux de bandes passantes adjacentes), et une adaptation large bande. Cette structure réunit à la fois des fonctions d‟accordabilité en fréquences (entre 8,7 et 15,6 GHz) par polarisation d‟éléments actifs, ceux-ci permettant même d‟obtenir du gain (de l‟ordre de 10 dB)
The aim of this work is to study “multi-functions” filters with an objective to reduce the dimensions of the circuits used for filtering functions in airborne systems. This work allows to obtain wide band notch filters (from 2 to 18 GHz) developed in MMIC technology using theEtude de Filtres MMIC Hyperfréquences en Technologies GaN et AsGa. 152GaN process and wide band filters developed in GaAs technology. The notch filters have been realized with two principles:- The first one based on coupled lines resonators structure. The prototype manufactured allow to validate the frequency tunability thanks to a variable load placed at the end of the coupled line. This can be realized with a varactor diode or with a cold transistor. These prototypes allow also validating the possibility for the circuit to work as an “allpass” filter or as a notch filter by applying a bias voltage on the transistors placed at the end of the coupled line.- The second one is based on the tenability of active filters by commuting between several channels thanks to a distributed structure. A prototype has been developed and manufactured in GaAs technology. This structure allow a frequency tunability with also the possibility to tune the bandwidth (by activating seeral channels with edge bandwidth), and a wide band matching. This structure allows to obtain frequency tunability (between 8.7 and 15.6 GHz) by applying a bias voltage on the active elements which brin gain (around 10 dB)

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Demirsoy, SuÌˆleyman SÄ±rrÄ±. "Complexity reduction in digital filters and filter banks." Thesis, University of Westminster, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433680.

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Maas, Susan. "Coaxial resonator filters." Thesis, Stellenbosch : Stellenbosch University, 2011. http://hdl.handle.net/10019.1/18067.

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Thesis (MScEng)--Stellenbosch University, 2011.
ENGLISH ABSTRACT: The purpose of this project is to develop a number of coaxial resonator lters. Firstly, the theoretical model of the lter is discussed, with a Tchebyscheff LC-ladder prototype lter used to derive a generalised bandpass lter. From this, generalised Combline- and Interdigital lters are derived. Following this, various options and limitations in the mechanics of microwave lters are discussed. Results are shown for an in-depth study considering the unloaded quality factor for thirteen di erent resonators. Each resonator is unique in the method of manufacturing, polishing, as well as plating. Utilizing the information obtained from the unloaded quality factor measurements, three coupled coaxial resonator lters, are designed for use in a radar system, namely a sixth order 2125 MHz Combline lter, a sixth order 9250 MHz Interdigital lter and a third order 9250 MHz Interdigital lter. Optimal results were obtained when both resonators and coupled transmission line lters were constructed from aluminium that was wire-cut and then silver electroplated.
AFRIKAANSE OPSOMMING: Die omvang van hierdie projek behels die ontwerp en bou van ko-aksiale resoneerder filters. Eerstens word die teoretiese modellering van die lters bespreek. 'n Tchebyscheff LC-leer prototipe filter word gebruik as basis vir 'n generiese banddeurlaat filter. Die banddeurlaat lter word gebruik om die afgeleide Kamlyn- en Interdigitale filter te de finieer. Hierna volg 'n bespreking aangaande die verskillende moontlikhede in die meganiese vervaardiging van mikrogolf filters. 'n Gedetailleerde studie word gedoen om die onbelaste kwaliteitsfaktore van 13 verskillende resoneerders te bepaal. Elkeen van hierdie resoneerders is uniek in die metode van vervaardiging, polering, asook die platering daarvan. Deur gebruik te maak van die resultate van die onbelaste kwaliteitsfaktore, word drie gekoppelde ko-aksiale resoneerder filters ontwikkel vir die gebruik in 'n radarstelsel, naamlik 'n sesde-orde 2125 MHz Kamlyn lter, 'n sesde orde 9250 MHz Interdigitale filter, asook 'n derde orde 9250 MHz Interdigitale filter. Die beste resultate was gevind toe beide resoneerders en gekoppelde ko-aksiale resoneerder filters vervaardig is uit aluminium wat gedraadsny en silwer geplateer is.

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Giménez, Bonastre Alfred Raul. "RF filters and multiplexers based on acoustic wave technologies with ladder-type and cross-coupled topologies. Designing under a systematic strategy." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/399512.

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La tecnologia mòbil ha emergit com la plataforma de major èxit per a la implantació de serveis innovadors i aplicacions d’usuari tant des d’un punt de vista tecnològic com econòmic. Els dispositius mòbils estan modiﬁcant els hàbits de comportament de les persones i veiem contínuament com, en aquest sentit, la nostra societat millora dia a dia. Amb la xarxa 4G en ple procés de desplegament i els futurs estàndards 5G en ple desenvolupament, la demanda global per al servei de dades de banda ampla ha estat sotmesa a un cicle de creixement imparable. I continuarà així alimentat per la ubiqüitat del servei, segons les previsions del Cisco. El més important ´es que aquest creixement indubtablement demostra la importància de la banda ampla per als ciutadans, la societat i l’economia, mentre dibuixa un gran repte als proveïdors de serveis de xarxa. L’objectiu d’aquest treball està centrat en el desenvolupament de tècniques de síntesi per al disseny de dispositius ﬁltrants basats en tecnologies micro-acústiques, enfocant així el gran repte de gestió de l’espectre freqüencial en el segment d’usuari. En general, el disseny d’aquest tipus de dispositius es basa en tècniques d’optimització degut a les rigoroses limitacions imposades per la viabilitat tecnològica dels ressonadors acústics, així com a les exigents especiﬁcacions de rendiment del dispositiu. És per aquests motius que el disseny i fabricació de ﬁltres i duplexors basats en tecnologia acústica creen un gran repte cada cop més difícil d’assolir. En aquest treball es proporcionen metodologies sistemàtiques enfocades en millorar i fer més eﬁcient el disseny de dispositius ﬁltrants basats en ressonadors acústics. El més important durant el disseny de ﬁltres i duplexors basats en tecnologia acústica ´es que els ressonadors siguin viables tecnològicament. Les diferents metodologies presentades en aquest treball són útils per a la síntesi de topologies en escalera o xarxes amb acoblaments creuats on la viabilitat tecnològica ´es un requisit indispensable en totes les solucions proporcionades. El coeﬁcient d’acoblament de cada ressonador, les freqüències de ressonància, el factor de qualitat, l’energia emmagatzemada, o l’àrea del xip son paràmetres que es tenen en compte durant el disseny d’aquest tipus de dispositius. Mitjançant les tècniques de síntesi proporcionades en aquest treball, no només es controlen analíticament aquestes restriccions, sinó que s’obtenen resultats òptims en el mínim temps i cost computacional. L’ús d’aquestes tècniques, a més, permet un control dels paràmetres de fase essencial per al disseny de multiplexors, els quals estan en el punt de mira com a dispositiu indispensable dins les capçaleres dels futurs sistemes sense ﬁls preparats per treballar amb el protocol de Carrier Aggregation dins els estàndards 4G-Advanced i 5G. Dispositius ﬁltrants, duplexors i multiplexors viables tecnològicament i complint amb les especiﬁcacions de màscara freqüencials són resultat de l’ús de les metodologies proposades en aquest treball.
The mobile technology has emerged as the most successful platform for the introduction of innovative services and user applications from both a technological and economical perspective. Mobile devices are changing the habits of the people and it is possible to see how, in this sense, our society is continuously improving. With the 4G network in process of deployment and the future 5G standards under development, global demand for broadband data services has been subjected to a series of unstoppable growth. And it will continue increasing pushed by the ubiquity of the service, according to Cisco's forecasts. The most important is that this growth undoubtedly demonstrates the importance of broadband services for the people, society, and economy, while it is drawing a major challenge for the network service providers. The aim of this work is to develop synthesis techniques for the design of filtering devices based on micro-acoustic technologies, focusing therefore the great challenge of frequency spectrum management in the user segment. In general, the design of these filtering devices is based on optimization techniques because of the stringent requirements imposed by the technological feasibility of acoustic resonators and the tight performance specifications of the device. For this reason, the design and manufacture of filters and duplexers based on acoustic resonators becomes a huge challenge increasingly difficult to achieve. In this work, systematic methodologies are presented in order to improve and make more efficient the design of filtering devices based on micro-acoustic technologies. The most important consideration during the synthesis of filters and duplexers is that the resonators must be technologically feasible. The methodologies presented in this work are useful for the design of ladder-type filters and cross-coupled prototypes in which the technological feasibility is an essential requirement for all the provided solutions. The effective coupling coefficient of each resonator, the resonant frequencies, the quality factor, the stored energy, or the chip size are parameters to consider during the design of micro-acoustic filters. By means of the techniques provided in this work, all these restrictions are analytically managed, and optimum results are obtained with a minimum time and computational effort. Moreover, the use of these synthesis techniques allows the control of the phase parameters, which are essential for the design of multiplexer devices. These are considered the main device for the future radio-frequency front-end modules ready to work with Carrier Aggregation and the 4G-Advanced and 5G standards. Stand-alone filtering devices, duplexers, and multiplexers, ready to accommodate the micro-acoustic technological requirements and satisfying the frequency mask specifications, as long as possible, are the result of the proposed methodologies in this work.

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Mlích, Jozef. "Sledování objektů ve videosekvencích." Master's thesis, Vysoké učení technické v Brně. Fakulta informačních technologií, 2008. http://www.nusl.cz/ntk/nusl-235922.

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In this master thesis, image processing methods and methods for statistical modeling of motion are presented. First, description methods of image processing, such as background subtraction method used for object detection, are presented. Next, description of morphological operations, such as dilatation and erosion, is done. Finally, methods for statistical modeling, such as Kalman filter and particle filters, are shown.

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Basti, Ahmed. "Développement de méthodes de synthèse pour la conception de filtres hyperfréquences compacts et optimisés en pertes." Thesis, Limoges, 2014. http://www.theses.fr/2014LIMO0023/document.

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Pour les systèmes de communication par satellite, des filtres avec de très bonnes performances électriques sont indispensables afin de rejeter les signaux indésirables dans de nombreuses parties de la chaîne de communication. Les technologies fort-Q peuvent répondre à cette exigence mais elles conduisent souvent à des dispositifs encombrants. D'autre part, les technologies compactes faible-Q souffrent généralement d'une dégradation des performances électriques en termes de pertes d'insertion, de sélectivité et de platitude. Pour répondre à une demande croissante concernant la réduction de la taille, il est essentiel de développer des filtres hyperfréquences compacts avec des performances électriques améliorées.Pour le filtre de réception, le défi est de concevoir un filtre passe-bande compact avec une réponse plate dans la bande passante et une forte réjection hors bande. Les pertes d'insertion ne sont pas cruciales et peuvent être compensées par un amplificateur en laissant ainsi un espace pour la conception de filtre à pertes. Un tel filtre accepte des pertes supplémentaires, qui peuvent être distribués dans le réseau afin de fournir une transmission plate dans la bande passante et une forte sélectivité hors bande.Dans le cadre de cette thèse, des nouvelles méthodes de synthèse de dispositifs de filtrage ont été étudiées et développées dans le but d’améliorer les performances tout en conservant un encombrement réduit. Ces méthodes ont été validées pour la conception de filtres de récepteur dans la charge utile de satellites de télécommunication dans le cadre d’une collaboration entre le laboratoire Xlim, le Centre National d’Etudes Spatiales et Thales Alenia Space
For satellite communication systems, high performance filters are needed in order to reject unwanted signals in many parts of the communication chain. High quality factor (Q) technologies can meet this requirement, but they often lead to bulky devices. On the other hand, compact technologies are generally low Q and suffer from a degradation of electrical performances in terms of insertion loss, selectivity and flatness. To meet a growing demand concerning size reduction, it is essential to develop compact microwave filters with improved electrical performances.For a receive filter, the challenge is to design a compact bandpass filter with a flat response in the passband and a sharp transition in the passband edges. The insertion loss is not crucial and it can be compensated by the amplifier, leaving a room to the design of a lossy filter. Such a filter accepts additional losses, which can be distributed in the network in order to provide a flat transmission in the passband and a sharp selectivity.In this thesis, new synthesis methods for filtering devices have been studied and developed to improve performances while maintaining a small footprint. These methods have been validated for the design of filters for a receiver in payload satellites as part of collaboration between the Xlim laboratory, the France National Space Centre and Thales Alenia Space

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Nikolina, Janković. "Mikrotalasni filtri sa više nezavisno kontrolisanih propusnih opsega realizovani u mikrostrip arhitekturi." Phd thesis, Univerzitet u Novom Sadu, Fakultet tehničkih nauka u Novom Sadu, 2013. https://www.cris.uns.ac.rs/record.jsf?recordId=83681&source=NDLTD&language=en.

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Filtri predstavljaju nezaobilazan deo svakog mikrotalasnog uređaja. Skorašnji veoma brz razvoj bežičnih sistema pred mikrotalasne filtre postavlja nove zahteve kao što su visoke performanse, kompaktnost i rad na više proizvoljno odabranih učestanosti koje se mogu nezavisno kontrolisati.Naučni doprinos ove doktorske disertacije predstavlja pet novih konfiguracija mikrotalasnih multi-band filtara koji su realizovani u mikrostrip arhitekturi. Od toga tri konfiguracije predstavljaju dual-band filtre, a preostale dve konfiguracije tri-band filtre. Filtri su realizovani korišćenjem fraktalnih krivih i/ili savijenih λ/4 rezonatora, i to u klasičnoj tehnologiji štampanih ploča i u višeslojnoj tehnologiji nisko-temperaturne zajedno pečene keramike.Detaljno je analiziran i opisan način rada predloženih filtara. Filtri su fabrikovani, a njihove performanse izmerene i upoređene sa drugim rezultatima dostupnim u literaturi. Pokazano je da predložene filtre karakteriše mogućnost nezavisne kontrole propusnih opsega što je iskorišćeno za realizaciju dual-band filtara koji rade na WLAN 2.4/3.5 GHz opsezima i tri-band filtara koji rade na WLAN 2.4/3.5/5.2 GHz opsezima. Štaviše, predložene tri-band strukture predstavljaju najmanje tri-band filtre do danas predložene u literaturi.
Filters are indispensable components in any microwave device. Recent rapid development of wireless systems posed new demands to microwave filters, such as high performance, compact size and the ability to simultaneously operate on several independently selected frequencies.Scientific contribution of this dissertation are five novel microwave multi-band filters realized in microstrip architecture. Out of the five, three configurations are dual-band filters, while the remaining two are tri-band filters. Filters are designed using fractal curves and/or folded λ/4 resonators, in the conventional printed circuits technology or in low-temperature cofired ceramics technology.Operating principles of the proposed filters have been analyzed and explained in detail. Their performances have been measured and compared to other recently published results. It has been shown that the proposed filters allow independent control of the passbands. This has been used to design dual-band filters operating at WLAN frequencies of 2.4/3.5 GHz and tri-band filters operating at WLAN frequencies of 2.4/3.5/5.2 GHz. Moreover, the proposed tri-band filters are the most compact tri-band filters published so far.

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Rosenbaum, Linnea. "On low-complexity frequency selective digital filters and filter banks." Doctoral thesis, Linköpings universitet, Elektroniksystem, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8930.

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En filterbank består av flera filter som arbetar tillsammans för att dela upp en signal i olika frekvensband. De kan också användas för att slå ihop signaler separerade i frekvensplanet till en enda. Sedan tidigt 70-tal har man lärt sig att designa förlustfria filterbankar som alltså inte introducerar några som helst fel i systemet. Sådana filterbankar kallas PR-filterbankar, där PR står för 'perfekt rekonstruktion'. Exempel på applikationer där filterbankar används är bildkodning, audiokodning, kommunikationssystem och omvandling av analoga signaler till digitala (A/D-omvandling). Under de senaste åren har det framkommit att genom att lätta på kraven gällande perfekt rekonstruktion, går det att markant minska den erforderliga aritmetiska komplexiteten. Eftersom de flesta system i sig inte är förlustfria, kan man utan att egentligen påverka den totala prestandan tillåta små fel i filterbanken, så l¨ange dessa fel är försumbara i jämförelse med andra felkällor som t.ex. kvantisering och avrundning. Avhandlingen behandlar digitala filter och likformiga icke-PR-filterbankar. Merparten av filterbankarna är realiserade med någon slags moduleringsteknik (cosinus-, sinus- eller komplexmodulering). Den röda tråden genom avhandlingen är kombinationen av tämligen smala övergångsband och samtidigt låg aritmetisk komplexitet. Ett sätt att uppnå denna kombination är att använda sig av en teknik som heter frekvenssvarsmaskning och förkortas FRM. Denna metod har på ett framgångsrikt sätt använts i avhandlingen. En potentiell nackdel med FRMmetoden är att den medför en längre fördröjning genom systemet. Därför föreslås också ett sätt att syntetisera FRM-filter med låg fördröjning. Här optimeras filtren både med avseende på komplexitet och fördröjning samtidigt. En annan metod som utnyttjats för att kombinera relativt smala övergångsband med låg aritmetisk komplexitet är att använda IIR filter istället för FIR filter. Ett flertal exempel på filter och filterbankar, optimerade och syntetiserade i Matlab, illustrerar fördelarna med de föreslagna filter- och filterbanks-klasserna.
Filter banks are systems of several filters with a common input or a common output. They are used whenever a signal needs to be split into different frequency bands. Since the early seventies, the theory of digital filter banks has developed to a mature state. Today there exist numerous ways to design filter banks for different applications, such as image and audio coding, transmultiplexing in communication systems, echo cancellation, and analog-to-digital (A/D) conversion systems. However, earlier work has to a large extent been on the transfer function level, whereas in this thesis work, efficient realizations, important in e.g. low-power applications, are in focus. Further, most of the previous work have been focused on the perfect reconstruction (PR) case, which is, for many applications an unnecessarily severe restriction. It has been show that by relaxing the requirements on perfect reconstruction, and allowing the filter banks to have some errors, the arithmetic complexity can be reduced significantly. This thesis treats digital filters and uniform non-PR filter banks. A major part of the filter banks are realized using different modulation schemes (complex, cosine, or sine modulation). The governing idea through the thesis is the combination of frequency selectivity and low arithmetic complexity. One example on how to achieve frequency selective digital filters and filter banks with low arithmetic complexity is to use the frequency-response masking (FRM) approach. This approach together with the idea of using IIR filters instead of FIR filters is successfully used in the thesis. The price to pay for the reduced arithmetic complexity using FRM filters is unfortunately a longer overall delay. Therefore, some work has ben done in the field of low-delay FRM FIR filters as well. These filters are optimized on both low delay and low arithmetic complexity simultaneously. A number of design examples are included in order to demonstrate the benefits of the new classes of filters and filter banks.

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Rosenbaum, Linnéa. "On low-complexity frequency selective digital filters and filter banks /." Linköping : Department of Eelectrical Engineering, Linköpings universitet, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-8930.

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Anderson, Martin S. "Design of two-dimensional PCAS digital filters and filter banks." Thesis, University of Warwick, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307968.

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Cadena, Pico Jorge Eduardo. "Perfect Reconstruction Filter Bank Structure Based On Interpolated FIR Filters." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71756.

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State of the art filter bank structures achieve practically perfect reconstruction with very high computational efficiency. However, the increase in computational requirements due to the need to process increasingly wider band signals is paramount. New filter bank structures that provide extra information about a signal while achieving the same level of required efficiency, and perfect reconstruction properties, need to be developed. In this work a new filter bank structure, the interpolated FIR (IFIR) filter bank is developed. Such a structure combines the concepts of filter banks, and interpolated FIR filters. The filter design procedures for the IFIR filter bank are developed and explained. The resulting structure was compared with the non-maximally-decimated filter bank (NMDFB), achieving the same performance in terms of the number of multiplications required per sample and the overall distortion introduced by the system, when operating with Nyquist prototype filters. In addition, the IFIR filter is tested in both simulated and real communication environments. Performance, in terms of bit-error-rate, was found to not be degraded significantly when using the IFIR filter bank system for transmission and reception of QPSK symbols.
Master of Science

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Chen, Tsuhan Vaidyanathan P. P. Vaidyanathan P. P. "Multidimensional multirate filters and filter banks : theory, design, and implementation /." Diss., Pasadena, Calif. : California Institute of Technology, 1993. http://resolver.caltech.edu/CaltechETD:etd-08232007-095226.

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Law, Ying Man. "Iterative algorithms for the constrained design of filters and filter banks /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202004%20LAW.

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Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004.
Includes bibliographical references (leaves 108-111). Also available in electronic version. Access restricted to campus users.

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Hicks, William T. "MEDIAN FILTERS." International Foundation for Telemetering, 2006. http://hdl.handle.net/10150/604155.

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ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California
Most modern digital filtering is done by taking the average (mean) of a signal or some weighted average. Another method is to use feedback, which more closely resembles how analog filters with feedback operate. In the case of low pass filters, all these methods tend to give a trade off in getting the signal to pass while attenuating the higher frequency noise. An alternative is to use a median filter, which selects the mid value of a group of points. While this is not as computationally simple as other filters, it allows for the attenuation of noise while allowing sudden changes in signal level to pass thru unaltered. This paper discusses the characteristics of median filters and methods of implementing them.

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Melgarejo, Lermas Juan Carlos. "Advanced Techniques for the Design and Optimization of Multi-Band and Reconfigurable Microwave Waveguide Filters." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/172728.

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[ES] El creciente número de dispositivos intercambiando datos ha empujado a las empresas del sector espacial a utilizar bandas de frecuencia cada vez más altas, como Ku, K y Ka, ya que permiten emplear canales de frecuencia más anchos. A medida que disminuye la longitud de onda, el tamaño de los filtros se reduce y, por tanto, son más sensibles a las desviaciones de fabricación. Para compensar estos errores, es necesario emplear elementos de sintonía en la etapa de diseño. En este contexto presentamos una estrategia de diseño que permite incluir todos los factores no ideales, como elementos de sintonía o esquinas redondeadas, en las simulaciones finales de filtros y multiplexores. Una vez se han fabricado los filtros es necesario ajustar manualmente los elementos de sintonía hasta recuperar la respuesta objetivo. Sin embargo, para realizar esta tarea con éxito es necesario tener mucha experiencia previa y, aún así, conlleva un tiempo considerable. Por tanto, también proponemos un procedimiento de sintonización eficiente y sistemático que permite a cualquier persona, independientemente de su experiencia previa en sintonización, realizar esta tarea con éxito. Además del aumento de las tasas de transmisión, otros desafíos del sector espacial son reducir el tamaño y peso de sus componentes, así como dotarlos de capacidad dereconfiguración. Emplear dispositivos multifunción como filtros multibanda o dispositivos reconfigurables es una posible solución. En este contexto, proponemos una nueva familia de filtros multibanda en guía de ondas que puede adaptarse a las futuras necesidades del sector espacial. Con el mismo objetivo, también proponemos una familia de dispositivos reconfigurables de varios estados discretos que pueden modificar su comportamiento de forma remota.
[CA] El creixent nombre de dispositius intercanviant dades ha empés a les empreses del sector espacial a utilitzar bandes de freqüència cada vegada més altes, com Ku, K i Ka, ja que permeten fer servir canals de freqüència més amples. A mesura que la longitud d'ona disminueix, la mida dels filtres es redueix i, per tant, són més sensibles a les desviacions de fabricació. Per compensar aquests errors, és necessari fer servir elements de sintonia en l'etapa de disseny. En aquest context presentem una estratègia de disseny que permet incloure tots els factors no ideals, com a elements de sintonia o cantonades arrodonides, en les simulacions finals de filtres i multiplexors. Una vegada s'han fabricat els filtres és necessari ajustar manualment els elements de sintonia fins a recuperar la resposta objectiu. Però, per realitzar aquesta tasca amb èxit és necessari tenir molta experiència prèvia i, així i tot, comporta un temps considerable. Per tant, també proposem un procediment de sintonització eficient i sistemàtic que permet a qualsevol persona, independentment de la seua experiència prèvia en sintonització, realitzar aquesta tasca amb èxit. A més de l'augment de les taxes de transmissió, altres desafiaments de el sector espacial són reduir la mida i pes dels seus components, així com dotar-los de capacitat de reconfiguració. Emprar dispositius multifunció com filtres multibanda o dispositius reconfigurables és una possible solució. En aquest context, proposem una nova família de filtres multibanda en guia d'ones que pot adaptar-se a les futures necessitats del sector espacial. Amb el mateix objectiu, també proposem una família de dispositius reconfigurables de diversos estats discrets que poden modificar el seu comportament de forma remota.
[EN] The need for ever increasing data rate of modern communication systems has motivated companies in the space sector to exploit higher frequency bands, such as Ku, K and Ka, in order to offer wider bandwidths to their customers. However, as the frequency increases, the wavelength decreases, and all waveguide hardware becomes smaller and more sensitive to deviations from the ideal dimensions that normally occur when manufacturing the devices. In order to compensate for these deviations (or errors), tuning elements must then be added to the hardware and included in the design process. In this context, therefore, we focus on the investigation of novel design strategies for filters and multiplexers with the objective of including all necessary non-ideal factors in the design process. It is important to note in this context that, once the filters are manufactured, the tuning elements are usually adjusted manually until the desired target performance has been achieved. However, successfully performing this task requires a considerable amount of time and very significant previous experience in tuning microwave filters. Consequently, an additional goal of our research work is to propose efficient and systematic tuning procedures so that anyone, regardless of their previous tuning experience, can successfully perform this difficult task. In addition to the increasing data rates, another current challenge of advanced communication systems is the ability to be reconfigured remotely to adjust to changes in costumer demands. The use of multi-function or reconfigurable devices is then an attractive possible solution. In this context, therefore, we also investigate new families of multi-band waveguide filters that can be used to accommodate several pass bands in the same filtering device. Furthermore, we also propose a new family of reconfigurable devices with several discrete states that can be easily controlled remotely.
Melgarejo Lermas, JC. (2021). Advanced Techniques for the Design and Optimization of Multi-Band and Reconfigurable Microwave Waveguide Filters [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172728
TESIS

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Aliouane, Kamel. "Contribution à l'étude du filtrage d'harmoniques des réseaux de distribution à l'aide de l'association de filtres actif et passif parallèle." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL012N.

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Cette thèse est consacrée à l'étude de l'association d'un filtre actif avec un filtre passif. Cette association peut conduire à une augmentation sensible des performances de filtrage ainsi que des potentialités d'application. Différentes structures sont envisageables, mais les deux configurations retenues (filtre actif en série avec l'alimentation ou en série avec le filtre passif) conduisent à un dimensionnement réduit du filtre actif, tout en assurant de bonnes performances de filtrage. Dans les deux cas, le filtre actif ne fonctionne pas comme un compensateur d'harmoniques. Il joue le rôle d'isolateur d'harmoniques, s'opposant en particulier aux phénomènes de résonance. C’est la raison pour laquelle il nécessite une plus faible puissance comparée à la puissance d'un filtre actif parallèle. Afin de valider l'étude effectuée, une maquette expérimentale monophasée de puissance réduite a été développée. Elle a permis de montrer que les caractéristiques de filtrage sont indépendantes de l'impédance de source et que les performances du filtre passif sont nettement améliorées

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Axman, Vladimír. "Obvody s moderními aktivními prvky." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2008. http://www.nusl.cz/ntk/nusl-233441.

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PhD. thesis is deals about sekond order ARC filters for cascade synthezis of Active filters. Here are presented new configurations of second order filters with current conveyors usable for higher frequencies and new second order filters with current conveyors usable for electrical tunable filters. In PhD. Thesis are presented schematics and equations for new sekond order filters. There are presented also practical realizations of these filters and basic measure results.

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Li, Shengyuan. "RF On-Chip Filters Using Q-enhanced LC Filters." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7169.

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Radio frequency (RF) filters are one of the key building blocks in modern microelectronic digital communication systems that use a narrow frequency band with strong interferers nearby. The objective of this thesis is to explore the better DR performance of RF filters using the Q-enhanced LC filter. It takes a divide-and-conquer method by designing 1. A new simple pseudo-differential pair (PDP) for input gm stage. It is the fastest, high-linearity, low-distortion, and wide-range constant-gm design reported to date. This has been applied in the final filter tape-out and has proven to be effective experimentally. 2. A new tunable discrete inductor (TDL) to achieve two-level inductance with the same real estate that can be used to expand the filtering frequency range. This has been verified experimentally. 3. A new tunable discrete capacitor (TDC) to achieve high linearity over wide terminal voltage swing range. This has been verified through simulation. 4. A new systematic way to achieve synchronized gain, center frequency, and filtering Q tuning capability for Q-enhanced LC filters. It has been verified through simulation. In order to verify the concept, a 900 MHz filter is designed and fabricated with National Semiconductor Company (NSC)'s standard 0.18 um digital epi-substrate CMOS technology, and packaged with NSC's LLP-28. The measurement results show that with filter Q of 17 at 845 MHz, the 1 dB compression point is measured to be +4 dBm, IIP3 to be +16 dBm with a peak noise floor of -154 dB/Hz, spurious free dynamic range (SFDR) to be 71 dB. With filter Q of 70 over a 20 MHz BW, the 1 dB compression point is measured to be -9.5 dBm, IIP3 to be +7 dBm with a peak noise floor of -141 dB/Hz, SFDR to be 57 over 20 MHz BW. This filter uses between 56 and 60 mA with a power supply of 1.8 V due to the low-Q (Q~1) of inductor. It is the RF filter with the highest DR in the published literature. The DR can be even higher if inductor Q can be improved as DR is proportional to Q^2.

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Bhattacharyya, Tumpa. "Filters on positive cones of lattice-ordered groups." Bowling Green State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1304540043.

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Llerena, Castro Oscar Enrique 1984. "Study of a compact microwave ceramic coaxial resonator filter : Estudo de um filtro compacto para microondas feito com ressonadores coaxias ceramicos." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/259187.

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Orientador: Hugo Enrique Hernandez-Figueroa
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-26T16:04:15Z (GMT). No. of bitstreams: 1 LlerenaCastro_OscarEnrique_M.pdf: 5834212 bytes, checksum: f007c788f1123ca923e5f860548252f0 (MD5) Previous issue date: 2014
Resumo: Os filtros passa-faixa feitos com ressonadores coaxiais cerâmicos são um tipo de tecnologia de filtro que fornece características de alta performance como a alta seletividade, ótimo desempenho em aplicações de alta potência, excelente rejeição, baixa perda de inserção na banda passante, etc. , e dado que os ressonadores são feitos de materiais de alta constante dielétrica consideravelmente, consequentemente, todas as características elétricas mencionadas anteriormente são compactadas em uma estrutura protegida o qual faz que este tipo de filtros sejam adequados para aplicações onde precisam-se de dispositivos de tamanho pequeno. A parte mais difícil no momento de projetar este tipo de filtros é encontrar as dimensões certas da estrutura, sejam as alturas dos ressonadores ou as dimensões da estrutura dos capacitores de acoplamento. Esta tese presenta um estudo feito neste tipo de filtro e propõe um procedimento analítico-empírico com formulas para projeção para facilitar a construção do arranjo de ressonadores e a estrutura dos capacitores de acoplamento. Este procedimento pode ser extrapolado para filtros passa-faixa com um maior número de ressonadores. As formulas de projeção permitem uma transição fácil do modelo circuital ao modelo eletromagnético do filtro. Isto deve-se com as formulas é fácil calcular os comprimentos dos ressonadores e os valores das capacitâncias requeridas para acoplar corretamente os ressonadores. A comparação entre as simulações no modelo circuital e o entorno eletromagnético mostram que as formulas de projeção propostas são uma ótima primeira aproximação para a projeção deste filtro
Abstract: Bandpass filters made with ceramic coaxial resonators are a kind of filter technology that provides high performance features like high selectivity, high power handling, excellent rejection, low passband insertion loss, etc. and given that the resonators are made of with materials of high dielectric constant it considerably reduces their size, consequently, all the electric characteristics mentioned before are "compacted" in a small shielded structure which make these filters suitable for applications where small sized devices are a necessity. The most difficult task when projecting this kind of filters is to find the correct dimensions of the structure, either the length of the resonators or the dimensions of the coupling capacitors structure. This thesis presents a study on this type of filter and propose an analytical-empirical procedure with design formulas to facilitate construction of the resonators array and the coupling capacitors structure. This procedure can be extrapolated to bandpass filters with a greater number of resonators. The design formulas allow an easy transition from the circuital model to the electromagnetic model of the filter. This is because they easily allow to compute the length of the resonators and the value of the capacitances required for a correctly resonators coupling. The comparison between the simulations in the circuital and the electromagnetic environment show that the proposed design formulas are a good first approximation for this filter design
Mestrado
Telecomunicações e Telemática
Mestre em Engenharia Elétrica

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Kumar, Bhunesh. "Design of Harmonic Filters for Renewable Energy Applications." Thesis, Högskolan på Gotland, Institutionen för kultur, energi och miljö, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:hgo:diva-1862.

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Harmonics are created by non-linear devices connected to the power system. Power system harmonics are multiples of the fundamental power system frequency and these harmonic frequencies can create distorted voltages and currents. Distortion of voltages and currents can affect the power system adversely causing power quality problems. Therefore, estimation of harmonics is of high importance for efficiency of the power system network. The problem of harmonic loss evaluation is of growing importance for renewable power system industry by impacting the operating costs and the useful life of the system components. Non-linear devices such as power electronics converters can inject harmonics alternating currents (AC) in the electrical power system. The number of sensitive loads that require ideal sinusoidal supply voltage for their proper operation has been increasing. To maintain the quality limits proposed by standards to protect the sensitive loads, it is necessary to include some form of filtering device to the power system. Harmonics also increases overall reactive power demanded by equivalent load. Filters have been devised to achieve an optimal control strategy for harmonic alleviation problems. To achieve an acceptable distortion, increase the power quality and to reduce the harmonics hence several three phase filter banks are used and connected in parallel. In this thesis, high order harmonics cases have been suppressed by employing variants of Butterworth, Chebyshev and Cauer filters. MATLAB/SIMULINK wind farm model was used to generate and analyze the different harmonics magnitude and frequency. High voltage direct current (HVDC) lines for an electrical grid that is more than50km far away wind farm generation plant was investigated for harmonics. These HVDC lines are also used in offshore wind farm plant. Investigated three-phase harmonics filters are shunt elements that are used in power systems for decreasing voltage distortion and for correcting the power factor. Renewable energy sources are not the stable source of energy generation like wind, solar and tidal e.t.c. Though they are secondary sources of generation and hard to connect with electrical grid. In near future the technique is to use the wave digital filter (WDF) or circulator-tree wave digital filter (CTWDF) for the renewable energy application can be employed to mitigate the harmonics. These WDF and CTWDF can b eused in HVDC lines and smart grid applications. A preliminary analysis is conducted for such a study.

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Silveira, Taboadela Patricia María. "Systematic Design Methodology for Acoustic Wave Filters Integrated in Multiplexers and Codesigned Modules." Doctoral thesis, Universitat Autònoma de Barcelona, 2021. http://hdl.handle.net/10803/673855.

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El desplegament mundial de la tecnologia 5G i l’ús estès de xarxes sense fils han impulsat un creixement accelerat del nombre de bandes freqüencials requerides pels telèfons intel·ligents i altres dispositius mòbils. De manera simultània, per incrementar la velocitat de connexió, també s’incrementen la complexitat de l’esquema de modulació, el nombre d’antenes i el nombre de portadores agregades. Aquestes especificacions requereixen avenços en la tecnologia de filtres d’RF per assegurar la selecció de la portadora adequada i de tota la informació transmesa. Alhora, dispositius més petits son necessaris en un espai cada cop més reduït i han de suportar nivells de potència més elevats en un escenari d’alta integració. Davant d’aquest desafiament, els ressonadors basats en tecnologia d’ona acústica han demostrat ser la solució que compleix amb els requeriments del mercat. El disseny d’un filtre d’ona acústica ha estat enfocat fins ara des de les tècniques d’optimització que requereixen un procés llarg i costós en termes de computació, una aproximació poc eficient des del punt de vista de la indústria. Però, eines de simulació basades en tècniques avançades de síntesi que consideren les restriccions tecnològiques han estat desenvolupades pel nostre grup en els darrers anys. Aquestes eines proporcionen solucions ràpides i precises com a primer pas per la posterior optimització de l’estructura. El propòsit principal d’aquesta tesi és aconseguir les demandes actuals d’integració de múltiples filtres en un sol mòdul (un multiplexor) i també incloure amplificadors de potència per reduir la mida de les capçaleres d’RF dels dispositius mòbils. En el cas dels multiplexors, el concepte de les xarxes de mínima susceptància ha estat empleat introduint el control de la fase del coeficient de reflexió per classificar aquestes xarxes. Dos escenaris han estat analitzats en quan al pla de freqüències: fixe i flexible. Aquest darrer és un cas complex que es troba impulsat en el paradigma de l’agregació de portadores i els requeriments del mercat. La metodologia proposada garanteix el compliment de les restriccions tecnològiques i dels requeriments d’atenuació de cada canal. En la part de la integració de filtres d’ona acústica en mòduls complets, aquesta tesi adreça la síntesi de filtres considerant impedàncies complexes a la càrrega i a la font. Aquesta proposta permet codissenyar filtres amb xarxes actives o passives permetent eliminar la tradicional etapa intermèdia d’adaptació d’impedàncies. El process de codisseny és il·lustrat amb amplificadors de potència i filtres analitzant les característiques de cara part per assegurar una alta eficiència i una alta potència de sortida en la banda. Alhora, una resposta de filtrat de Chebyshev s’obté en el dispositiu resultant. De la mateixa manera, el control de la fase amb diversos objectius s’ha discutit en aquesta tesi. L’anàlisi teòric queda suportat per exemples simulats i prototips fabricats que demostren la validesa de la hipòtesi. Els resultats aconseguits es troben resumits al final de cada capítol.
La implementación de la tecnología 5G a nivel mundial y el extendido uso de conexiones inalámbricas han impulsado el incremento acelerado del número de bandas de radio frecuencia (RF) que deben ser soportadas por los teléfonos inteligentes y los dispositivos móviles. Al mismo tiempo aumenta la complejidad de los esquemas de modulación, el número de antenas y la cantidad de portadoras con el objetivo de aumentar la velocidad de conexión. Estas demandas requieren avances en la tecnología de filtros de RF que garanticen la selección correcta de cada portadora y la adquisicion íntegra de la información deseada. Sumamos además la necesidad de tener dispositivos cada vez más pequeños en un espacio cada vez más reducido y capaces de manejar mayores potencias en un escenario de alta integración. En este contexto tan desafiante, los filtros basados en resonadores de tecnología microacústica han demostrado ser la solución para cubrir las necesidades del mercado. El diseño de filtros en esta tecnología ha estado dominado por técnicas de optimización que requieren un gran tiempo de procesado y un esfuerzo computacional no eficientes desde el punto de vista industrial. Sin embargo, herramientas de simulación basadas en métodos de síntesis avanzados que consideran los requerimientos propios de la tecnología han sido desarrollados en los últimos años en nuestro grupo de investigación con el objetivo de proporcionar una solución precisa y rápida que sirva de semilla para una posterior optimización. Esta tesis persigue como objetivo dar respuesta a la tendencia actual de integración de múltiples filtros en módulos de RF que incluyen amplificadores de potencia (PA) para disminuir la ocupación dentro de los smartphones. Durante el proceso de diseño de multiplexores he aplicado conceptos con fundamentos teóricos sólidos como las Redes de Mínima Susceptancia y he introducido el control de la fase en el proceso de síntesis como elemento clave en la clasificación de dichas redes de filtrado. Dos posibles escenarios fueron analizados según el plan de frecuencia: fijo y flexible. Este último escenario es especialmente complejo y constituye una demanda industrial reciente debido a la aparición de la tecnología de Carrier Aggregation. La metodología presentada garantiza la viabilidad tecnológica y el cumplimiento de las especificaciones para cada banda de frecuencia. Como parte de la integración en módulos, esta tesis también incluye la síntesis de filtros acústicos con impedancia compleja a la entrada y/o salida. Esta propuesta permite el codiseño de filtros con elementos activos o pasivos para eliminar redes intermedias de adaptacion de impedancia. Se ilustra el proceso de codiseño de amplificadores de potencia y filtros en tecnología microacústica desde un punto de vista integrador para garantizar una alta eficiencia en la conversión de energía y potencias de salida estables en toda la banda de frecuencia. Simultáneamente, una respuesta de filtrado tipo Chebyshev es obtenida en el dispositivo final. El control de la fase con diferentes objetivos es también abordado en este documento. Todos los análisis teóricos han sido acompañados de ejemplos simulados y prototipos fabricados que demuestran la ideoneidad de los planteamientos. Los resultados alcanzados han sido resumidos en cada capítulo.
The worldwide implementation of 5G technology and the extended use of wireless networks have boosted the fast-paced increase in the radio frequency bands number supported by smartphones and other mobile devices. Simultaneously, to increment the connection speed, the modulation scheme complexity, antenna number, and carrier aggregated are increasing. These specifications require advances in the RF filter technology to ensure the proper selection of each carrier and the full information acquisition. Additionally, smaller devices are needed for a shrinking space and also be able to handle higher powers in a highly integrated scenario. In this challenging environment, resonators based on acoustic wave (AW) technology have demonstrated to be the solution for the market requirements. The AW filter design has been driven by optimization techniques that require a time-consuming process and computational efforts, being inefficient from the industry point of view. Nevertheless, simulation tools based on advanced synthesis techniques considering the technological accommodation have been developed in our research group in the last years. These tools provide precise and fast solutions as the first tier for a later optimization procedure. The principal purpose of this thesis is to meet the current demands of integration of multiple filters in one RF module, namely multiplexers, and also including power amplifiers (PA) to reduce the device size inside the smartphones. For the multiplexers design, the Minimum Susceptance Networks (MSN) concept has been exploited, introducing the reflection coefficient phase control as a key element for this kind of network classification. Two probable scenarios were analyzed regarding the frequency plan: fixed and flexible. The latter is a complex case boosted by the advent of the Carrier Aggregation technology and the market requirements. The proposed methodology guarantees technological feasibility and mask specifications fulfillment for each channel. As part of the AW filters module integration, this thesis addresses the synthesis considering complex source/load impedances. The proposal allows the co-design of filters with active or passive networks removing the common inter-stage matching network. It is illustrated the co-design process for power amplifiers and filters analyzing each part's features to ensure high efficiency and output power in the passband. Simultaneously, a Chebyshev filter response is obtained in the resulting device. Moreover, the phase control with different purposes is also discussed in this document. The theoretical analysis has been supported by simulated examples and manufacturing prototypes that show the approach's pertinence. The achieving results have been summarized at each chapter's end.
Universitat Autònoma de Barcelona. Programa de Doctorat en Enginyeria Electrònica i de Telecomunicació

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Eshghi, Mohammad. "Highly parallel transversal adaptive filter." Ohio : Ohio University, 1988. http://www.ohiolink.edu/etd/view.cgi?ohiou1182785469.

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Shadrin, Aleksandr. "Analogové pole pro realizaci programovatelného filtru." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-221026.

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The state-variable analog filter topologies are described. Using the transfer function theory and operational configurations suitable for integration and derivation, a new universal filter topology are proposed. The circuit has been implemented in CMOS technology by using six operational amplifiers, eight analog switches and five programming resistor array. Tunable corner frequencies, quality factors and gain are realized. Using the serial peripheral interface or digital memory can be realized this real-time digitally programmable first- and second-order analog filter with the tunable parameters.

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Contreras, Lizarraga Adrián Arturo. "Multimodal microwave filters." Doctoral thesis, Universitat Politècnica de Catalunya, 2013. http://hdl.handle.net/10803/134931.

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This thesis presents the conception, design and implementation of new topologies of multimodal microwave resonators and filters, using a combination of uniplanar technologies such as coplanar waveguide (CPW), coplanar strips (CPS) and slotlines. The term "multimodal" refers to uniplanar circuits in which the two fundamental modes of the CPW propagate (the even and the odd mode). By using both modes of the CPW, it is possible to achieve added functions, such as additional transmission zeros to increase the rejection, or to attenuate harmonic frequencies to improve the out-of-band rejection. Moreover, it is demonstrated that by using multimodal circuits, it is possible to reduce the length of of a conventional filter up to 80%. In addition to bandpass filters, new topologies of compact band-stop filters are developed. The proposed band-stop filters make use of slow-wave resonators to decrease the total area of the filters and achieve compact topologies. This work also addresses the development of synthesis techniques for each multimodal filter. The design equations were obtained from generalized multimodal circuits available in the literature, which have been adapted for each particular case and modeled as basic filter components, such as immitance inverters or lumped elements. By using the proposed synthesis equations, it is possible to design filters with a desired response and relative bandwidth. The use of the proposed synthesis enables a fast analysis and design of multimodal filters using circuit simulators. As an added feature, several reconfigurable and tunable filter topologies were demonstrated, using active devices (PIN diodes and varactors) or RF-MEMS. These new topologies demonstrate the flexibility of multimodal circuits. For the RF-MEMS-based tunable filters, different capacitive and ohmic switches were designed, fabricated and measured. As an example of the additional degrees of freedom using of RF-MEMS and multimodal CPW circuits, a reconfigurable filter using RF-MEMS switchable air-bridges as a reconfiguration device has been demonstrated in this work for the first time.

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Edgington, Padraic D. "Modular Bayesian filters." Thesis, University of Louisiana at Lafayette, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=3712276.

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In this dissertation, I introduce modularization as a means of efficiently solving problems represented by dynamic Bayesian networks and study the properties and effects of modularization relative to traditional solutions. Modularizing a Bayesian filter allows its results to be calculated faster than a traditional Bayesian filter. Traditional Bayesian filters can have issues when large problems must be solved within a short period of time. Modularization addresses this issue by dividing the full problem into a set of smaller problems that can then be solved with separate Bayesian filters. Since the time complexity of Bayesian filters is greater than linear, solving several smaller problems is cheaper than solving a single large problem. The cost of reassembling the results from the smaller problems is comparable to the cost of the smaller problems. This document introduces the concept of both exact and approximate modular Bayesian filters and describes how to design each of the elements of a modular Bayesian filters. These concepts are clarified by using a series of examples from the realm of vehicle state estimation and include the results of each stage of the algorithm creation in a simulated environment. A final section shows the implementation of a modular Bayesian filter in a real-world problem tasked with addressing the problem of vehicle state estimation in the face of transitory sensor failure. This section also includes all of the attending algorithms that allow the problem to be solved accurately and in real-time.

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Campbell, Robert John. "Nonlinear interference filters." Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/989.

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Mackle, John. "Integrated digital filters." Thesis, Queen's University Belfast, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.334588.

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SILVA, ROMULO BRITO DA. "INVARIANT DERIVATIVE FILTERS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2013. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=22234@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
PROGRAMA DE SUPORTE À PÓS-GRADUAÇÃO DE INSTS. DE ENSINO
Os dados adquiridos nos experimentos físicos e nas imagens geométricas ou médicas são tipicamente discretas. Esses dados são interpretados como amostras de uma função desconhecida, porém cujas derivadas servem para caracterizar o dado. Por exemplo, o movimento de um fluido é descrito por um campo de velocidades, uma curva é caracterizada pela evolução da sua curvatura, as imagens médicas são geralmente segmentadas por estimativas de gradiente, entre outros. É possível obter derivadas coerentes a partir de filtragem dos dados. Porém, em dados multi-dimensionais, os filtros usuais privilegiam direções alinhadas com os eixos, o que pode gerar problemas quando essas derivadas são interpretadas geometricamente. Por exemplo, a curvatura estimada dependeria da orientação da curva, perdendo o sentido geométrico da curvatura. O objetivo do presente trabalho é melhorar a invariância geométrica dos filtros de derivadas.
Typical data acquired in physical experiments or in geometrical or medical imaging are discrete. This data is generally interpreted as samples of an unknown function, whose derivatives still serve for the data characterisation. For example, the movement of a fluid is described as a velocity field, a curve is characterised by the evolution of its curvature, images used in medical sciences are usually segmented by estimates of their gradients, among others. It is possible to obtain coherent derivatives by filtering the data. However, with multidimensional data, the usual filters present a bias towards to favor directions aligned with the axis, which may induce problems when the derivatives are interpreted geometrically. For example, the estimated curvature would depend on the orientation of the curve, loosing the geometric meaning of the curvature. The goal of the present work is to improve the geometric invariance of derivative filters.

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Prasad, Bhagwati. "Perovskite spin filters." Thesis, University of Cambridge, 2015. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.709021.

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Llamas, Garro Ignacio. "Micromachined microwave filters." Thesis, University of Birmingham, 2003. http://etheses.bham.ac.uk//id/eprint/102/.

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Microwave circuits in the millimetre wave region demand low loss, and low dispersion transmission lines. The work carried out in this thesis is on low loss transmission lines and filters, based on a square coaxial transmission line which is made only of metal, avoiding dielectric and radiation losses. The metal structure inside the square coaxial transmission line is supported by stubs, which provide the mechanical support for the centre conductor for the coaxial transmission lines and filters. The coaxial structure is made by stacking thick planar layers of material to suit microfabrication, providing the means to design high Q Microwave and RF passive devices, this transmission line structure is compact compared with a microstrip or a stripline, and gives better loss performance. Through this thesis, the way of optimising the square coaxial transmission line to provide a low loss will be presented, which will end in the presentation of one dielectric supported coaxial structure and three self supported filters, three of them were designed for the X-band, and one of them was designed for the Ka band. The application of the coaxial transmission line is demonstrated with wideband and narrow band designs.

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Li, Kai. "Generalised particle filters." Thesis, Imperial College London, 2013. http://hdl.handle.net/10044/1/10749.

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The ability to analyse, interpret and make inferences about evolving dynamical systems is of great importance in different areas of the world we live in today. Various examples include the control of engineering systems, data assimilation in meteorology, volatility estimation in financial markets, computer vision and vehicle tracking. In general, the dynamical systems are not directly observable, quite often only partial information, which is deteriorated by the presence noise, is available. This naturally leads us to the area of stochastic filtering, which is defined as the estimation of dynamical systems whose trajectory is modelled by a stochastic process called the signal, given the information accumulated from its partial observation. A massive scientific and computational effort is dedicated to the development of various tools for approximating the solution of the filtering problem. Classical PDE methods can be successful, particularly if the state space has low dimensions (one to three). In higher dimensions (up to ten), a class of numerical methods called particle filters have proved the most successful methods to-date. These methods produce approximations of the posterior distribution of the current state of the signal by using the empirical distribution of a cloud of particles that explore the signal’s state space. In this thesis, we discuss a more general class of numerical methods which involve generalised particles, that is, particles that evolve through spaces larger than the signal’s state space. Such generalised particles include Gaussian mixtures, wavelets, orthonormal polynomials, and finite elements in addition to the classical particle methods. This thesis contains a rigorous analysis of the approximation of the solution of the filtering problem using Gaussian mixtures. In particular we deduce the L2-convergence rate and obtain the central limit theorem for the approximating system. Finally, the filtering model associated to the Navier-Stokes equation will be discussed as an example.

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Ryan, James Gregory Carleton University Dissertation Engineering Electrical. "Subband adaptive filters." Ottawa, 1992.

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Swarnakar, Vivek. "Optimal morphological filters /." Online version of thesis, 1993. http://hdl.handle.net/1850/11703.

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Chen, Min. "Implementation and optimization of a modulated filter bank based on allpass filters." Thesis, University of Ottawa (Canada), 2001. http://hdl.handle.net/10393/9192.

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A filter bank based on an allpass IIR filter with brick-wall response was designed by A. J. Van Leest in [17]; however, the delay in the filter bank is too long to be used in real time applications. In order to reduce the delay, the orders of coefficients, transition bandwidth and filter bank structures must be optimized. The order of coefficients can be reduced by increasing the stopband attenuation. In order to further reduce the delay, the sharpness of the filter bank has to be reduced. This thesis also discussed the number of band and filter bank structure against to filter bank delay. The filter bank can be used in non-real time application such as CD compression with high order coefficient. The minimum transition bandwidth can be reached at 0.03257pi/number of band. This thesis expands upon DCT modulations of IIR based modulated filter banks and investigate the Hartley transformation in filter bank modulation as a new modulation technique. These modulation techniques generate the real output signal with real input signals. The quantization errors from quantizing the coefficient are studied. It is concluded that at least 16 bits are required in order for a filter bank to give a good performance as designed without quantization.

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Baicher, Gurvinder Singh. "Towards optimisation of digital filters and multirate filter banks through genetic algorithms." Thesis, University of South Wales, 2003. https://pure.southwales.ac.uk/en/studentthesis/towards-optimisation-of-digital-filters-and-multirate-filter-banks-through-genetic-algorithms(1ed2778b-e27b-4434-bc50-915f697a0d6b).html.

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This thesis is concerned with the issues of design and optimisation of digital filters and multirate filter banks. The main focus and contribution of this thesis is to apply the genetic algorithm (GA) technique and to draw some comparison with the standard gradient and non-gradient based optimisation methods. The finite word length (FWL) constraint affects the accuracy of a real-time digital filter requency response. For the case of digital filters, this study is concerned with the optimisation of FWL coefficients using genetic algorithms. Some comparative study with the simple hill climber algorithms is also included. The outcome of this part of the study demonstrates a substantial improvement of the new results when compared with the simply rounded FWL coefficient frequency response. The FWL coefficient optimisation process developed in the earlier Chapters is extended to the field of multirate filter banks. All multirate filter banks suffer from the problems of amplitude, phase and aliasing errors and, therefore, constraints for perfect reconstruction (PR) of the input signal can be extensive. The problem, in general, is reduced to relaxing constraints at the expense of errors and finding methods for minimising the errors. Optimisation techniques are thus commonly used for the design and implementation of multirate filter banks. In this part of the study, GAs have been used in two distinct stages. Firstly, for the design optimisation so that the overall errors are minimised and secondly for FWL coefficient optimisation of digital filters that form the sub-band filters of the filter bank. This process leads to an optimal realisation of the filter bank that can be applied to specific applications such as telephony speech signal coding and compression. One example of the optimised QMF bank was tested on a real-time DSP target system and the results are reported. The multiple M-channel uniform and non-uniform filter banks have also been considered in this study for design optimisation. For a comparative study of the GA optimised results of the design stage of the filter bank, other standard methods such as the gradient based quasi-Newton and the non-gradient based downhill Simplex methods were also used. In general, the outcome of this part of study demonstrates that a hybrid approach of GA and standard method was the most efficient and effective process in generating the best results.

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Morzfeld, Matthias, Daniel Hodyss, and Chris Snyder. "What the collapse of the ensemble Kalman filter tells us about particle filters." TAYLOR & FRANCIS LTD, 2017. http://hdl.handle.net/10150/623125.

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The ensemble Kalman filter (EnKF) is a reliable data assimilation tool for high-dimensional meteorological problems. On the other hand, the EnKF can be interpreted as a particle filter, and particle filters (PF) collapse in high-dimensional problems. We explain that these seemingly contradictory statements offer insights about how PF function in certain high-dimensional problems, and in particular support recent efforts in meteorology to 'localize' particle filters, i.e. to restrict the influence of an observation to its neighbourhood.

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Katsianos, Themis G. "Digital recursive filters : a tutorial for filter designers with examples implemented in Csound and supercollider." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28283.

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Filters constitute an essential tool for manipulating the spectral content of a signal. While there is a plethora of filtering tools, both in the hardware and software domain, the majority of them are geared towards engineers and scientists, rather than sound designers and electroacoustic composers. The "common-practice" approach is to consider filters as post-production tools. This can be restrictive if filters are to be used as artistic tools, dynamically involved in the shaping of the sound. This thesis was written with this approach in mind its aim is (a) to provide a survey of the various digital recursive filters, enabling a filter designer to choose the one that suits his needs, (b) to teach filter designers, such as electroacoustic composers and sound designers how to calculate digital filter coefficients, and (c) implement filter algorithms using the familiar syntax of computer music languages such as Csound and SuperCollider .

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Hicks, William T. "An Analysis of Various Digital Filter Types for Use as Matched Pre-Sample Filters in Data Encoders." International Foundation for Telemetering, 1995. http://hdl.handle.net/10150/611585.

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International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada
The need for precise gain and phase matching in multi-channel data sampling systems can result in very strict design requirements for presample or anti-aliasing filters. The traditional use of active RC-type filters is expensive, especially when performance requirements are tight and when operation over a wide environmental temperature range is required. New Digital Signal Processing (DSP) techniques have provided an opportunity for cost reduction and/or performance improvements in these types of applications. This paper summarizes the results of an evaluation of various digital filter types used as matched presample filters in data sampling systems.

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Jelavic, Simon. "Detail Preserving Filters for Impulsive Noise Removal in Color Images." Honors in the Major Thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETH/id/1227.

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This item is only available in print in the UCF Libraries. If this is your Honors Thesis, you can help us make it available online for use by researchers around the world by following the instructions on the distribution consent form at http://library.ucf.edu/Systems/DigitalInitiatives/DigitalCollections/InternetDistributionConsentAgreementForm.pdf You may also contact the project coordinator, Kerri Bottorff, at kerri.bottorff@ucf.edu for more information.
Bachelors
Engineering and Computer Science
Electrical Engineering

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Druckmüllerová, Hana. "Application of Adaptive Filters in Processing of Solar Corona Images." Doctoral thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-234232.

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Fotografování sluneční koróny patří mezi nejobtížnější úlohy astrofotografie a zároveň je jednou z klíčových metod pro studium koróny. Tato práce přináší ucelený souhrn metod pro pozorování sluneční koróny pomocí snímků. Práce obsahuje nutnou matematickou teorii, postup pro zpracování snímků a souhrn adaptivních filtrů pro vizualizaci koronálních struktur v digitálních obrazech. Dále přináší návrh nových metod určených především pro obrazy s vyšším obsahem šumu, než je běžné u obrazů bílé koróny pořízených během úplných zatmění Slunce, např. pro obrazy pořízené pomocí úzkopásmových filtrů. Fourier normalizing-radial-graded filter, který byl navržen v rámci této práce, je založen na aproximaci hodnot pixelů a jejich variability pomocí trigonometrických polynomů s využitím dalších vlastností obrazu.

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Rosler, Lucas Owen. "Design and Analysis of an FPGA Based Low Tap Band-stop FIR Filter." Youngstown State University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1619798270047225.

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Getachew, Sileshi Biruk. "Algorithmic and Architectural optimization techniques in particle filtering for FPGA-Based navigation applications." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/393935.

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Els filtres de partícules (FPs) són una tipologia de tècniques d'estimació bayesiana basades en simulacions Monte Carlo que es troben entre els sistemes d'estimació que ofereixen millors rendiments i major flexibilitat en la resolució de problemes d’estimació no lineals i no gaussians. No obstant això, aquest millor rendiment i major flexibilitat es contraposa amb la major complexitat computacional del sistema, motiu pel que fins ara la seva aplicació a problemes de temps real ha estat limitada. La majoria de les aplicacions en temps real, en particular en el camp de la robòtica mòbil, com ara el seguiment, la localització i mapatge simultani (SLAM) i la navegació, tenen limitacions en el rendiment, l'àrea, el cost, la flexibilitat i el consum d'energia. La implementació software de FPs en plataformes d’execució seqüencial en aquestes aplicacions és sovint prohibitiu per l’elevat cost computacional. Per tant per aproximar els FPs a aplicacions en temps real és necessària l'acceleració de les operacions de còmput utilitzant plataformes hardware. Donat que la major part de les operacions es poden realitzar de forma independent, el pipeline i el processament en paral·lel poden ser explotats de manera efectiva mitjançant l'ús de hardware apropiat, com ara utilitzant Field Programmable Gate Arrays (FPGAs). La flexibilitat que tenen per introduir la paral·lelització fa que puguin ser emprades en aplicacions de temps real. Amb aquest enfocament, aquesta tesis doctoral s’endinsa en el difícil repte d’atacar la complexitat computacional dels filtres de partícules introduint tècniques d’acceleració hardware i implementació sobre FPGAs, amb l’objectiu d’incrementar el seu rendiment en aplicacions de temps real. Per tal d’implementar filtres de partícules d’alt rendiment en hardware,aquesta tesis ataca la identificació dels colls d’ampolla computacionals en FPs i proposa, dissenya i implementa tècniques d’acceleració hardware per a FPs. Emprant tècniques d’acceleració hardware per a filtres de partícules primer es dissenya i implementa una arquitectura HW/SW per a FPs. Després, es dissenya un processador hardware per a FPs en el que es detallen totes les etapes del FP aplicant-lo a un algorisme de mapatge i localització simultània i implementant-lo sobre FPGA. També es dissenya i implementa un co-processador paral·lel per a un escàner làser emprat en FPs emprant un algorisme de Bresenham. Aquesta proposta hardware ha conduit al desenvolupament del primer prototip totalment hardware (sobre FPGA) per a filtres de partícules emprats en SLAM.
Los filtros de partículas (FPs) son una tipología de técnicas de estimación bayesiana basadas en simulaciones Monte Carlo que se encuentran entre los sistemas de estimación que ofrecen mejores rendimientos y mayor flexibilidad en la resolución de problemas de estimación no lineales y no gausianos . Sin embargo, este mejor rendimiento y mayor flexibilidad se contrapone con la mayor complejidad computacional del sistema, por lo que hasta ahora su aplicación a problemas de tiempo real ha sido limitada. La mayoría de las aplicaciones en tiempo real, en particular en el campo de la robótica móvil, aplicaciones tales como el seguimiento, la localización y mapeo simultáneo (SLAM) y la navegación, tienen limitaciones en el rendimiento, el área, el coste, la flexibilidad y el consumo de energía. La implementación software de FPs en plataformas de ejecución secuencial en estas aplicaciones es a menudo prohibitivo por el elevado coste computacional. Por lo tanto para aproximar los FPs a aplicaciones en tiempo real es necesaria la aceleración de las operaciones de cómputo utilizando plataformas hardware. Dado que la mayor parte de las operaciones se pueden realizar de forma independiente, el pipeline y el procesamiento en paralelo pueden ser explotados de manera efectiva mediante el uso de hardware apropiado, como utilizando Field Programmable Gate Arrays (FPGAs). La flexibilidad que tienen para introducir la paralelización hace que puedan ser utilizadas en aplicaciones de tiempo real. Con este enfoque, esta tesis doctoral se adentra en el difícil reto de atacar la complejidad computacional de los filtros de partículas introduciendo técnicas de aceleración hardware e implementación sobre FPGAs, con el objetivo de incrementar su rendimiento en aplicaciones de tiempo real. Para implementar filtros de partículas de alto rendimiento en hardware, esta tesis ataca la identificación de los cuellos de botella computacionales en FPs y propone, diseña e implementa técnicas de aceleración hardware para FPs. Empleando técnicas de aceleración hardware para filtros de partículas primero se diseña e implementa una arquitectura HW/SW para FPs. Después, se diseña un procesador hardware para FPs en el que se detallan todas las etapas del FP aplicándolo a un algoritmo de mapeo y localización simultánea y implementándose en FPGA. También se diseña e implementa un co-procesador paralelo para un escáner láser empleado en FPs empleando un algoritmo de Bresenham. Esta propuesta hardware ha conducido al desarrollo del primer prototipo totalmente hardware (FPGA) para filtros de partículas empleados en SLAM.
Particle filters (PFs) are a class of Bayesian estimation techniques based on Monte Carlo simulations that are among the estimation frameworks that offer superior performance and flexibility on addressing non-linear and non Gaussian estimation problems. However, such superior performance and flexibility of PFs comes at the cost of higher computational complexity that has so far limited their applications in real time problems. Most real time applications, in particular in the field of mobile robotics, such as tracking, simultaneous localization and mapping (SLAM) and navigation, have constraints on performance, area, cost, flexibility and power consumption. Software implementation of the PFs on sequential platforms for such applications is often prohibitive for real time applications. Thus to make PFs more feasible to such real-time applications, the acceleration of PFs computations using hardware circuitry is essential. As most of the operations in PFs can be performed independently, pipelining and parallel processing can be effectively exploited by use of an appropriate hardware platform, like field programmable gate arrays (FPGA), which offer the flexibility to introduce parallelization and lead to a wide range of applications of PFs in real time systems. Thus the focus of this phD thesis is to address the challenge of to deal with the computational complexity of PFs introducing FPGA hardware acceleration for improving their real-time performance and make its use feasible in these applications. For a high throughput hardware realization of the PFs, some of the issues addressed in this thesis include: the identification in the computational bottlenecks of the PFs and the proposal and design of PF hardware acceleration techniques. Based on the PF hardware acceleration techniques, the design and implementation of a PF HW/SW architecture is presented. In addition, a new approach for full parallelization of the PFs is presented which leads to a distributed particle filtering implementation with simplified parallel architecture. Finally, the design of a fully hardware PF processor is provided where the whole particle filtering steps applied to the SLAM problem are proposed for an implementation on FPGA. As part of the PF processor design, important problems for PF in SLAM are also solved. Also, the design and implementation of a parallel laser scanner as a PF co-processor using a Bresenham line drawing algorithm is realized. The proposed hardware architecture has led to the development of the first fully hardware (FPGA) prototype for the PF applied to the SLAM problem.

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Stander, Tinus. "High-power broadband absorptive waveguide filters." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/1157.

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Thesis (PhD (Electrical and Electronic Engineering))--University of Stellenbosch.
ENGLISH ABSTRACT: This dissertation presents a synthesis method for broadband high-power absorptive microwave lters by cascading a wide stop-band wa e-iron lter with an absorptive harmonic pad. The classical image impedance synthesis methods for wa e-iron lters are updated to allow for non-uniform boss patterns, which enable control over both the stop-band attenuation and pass-band re ection of the lter. By optimising an accurate circuit model equivalent, computationally intensive numerical EM optimisation are avoided. The nonuniform wa e-iron lter achieves the same electrical speci cation as similar lters in literature, but in a smaller form factor. The prototype presented displays less than -21 dB in-band re ection over 8.5 - 10.5 GHz, with stop-band attenuation in excess of 50 dB over the harmonic bands 17 - 31.5 GHz and 30 dB over the 34 - 42 GHz. The prototype is designed to handling 4 kW peak power incident in the transmitted band, and is 130 mm in length. Minimal full-wave tuning is required post-synthesis, and good agreement is found between synthesised and measured responses. Additionally, a completely novel oblique wa e-iron boss pattern is proposed. For the absorptive harmonic pad, transversal broadwall slots in rectangular waveguide, coupling to an absorptive auxiliary guide, are investigated in the presence of standing wave surface current distributions. An accurate circuit model description of the cascaded structure is developed, and optimised to provide a required level of input match in the presence of an arbitrary re ective lter. Using numerical port parameter data of the wa eiron lter, a harmonic pad is developed that provides -12.5 dB input re ection match across the band 17 - 21 GHz with up to 1 kW peak incident power handling capability, yet is only 33 mm in length. Again, good agreement is found between synthesised and measured responses of the cascaded structure.
AFRIKAANSE OPSOMMING: Hierdie proefskrif stel 'n sintesetegniek voor vir wyeband, ho edrywing absorberende mikrogol lters deur 'n kaskade kombinasie van 'n verlieslose wafelyster lter met 'n wye stopband, en 'n absorberende harmoniekdemper. Die klassieke sintesemetodes vir wafelyster lters word aangepas om nie-uniforme tandpatrone toe te laat, wat beheer oor beide die lter se stopband attenuasie en deurlaatband weerkaatsing moontlik maak. Deur die optimering van 'n akkurate stroombaanmodel van die lter kan berekeningsintensiewe numeriese EM optimering vermy word. Die nieuniforme wafelyster lter behaal dieselfde spesi kasies as soortgelyke gepubliseerde lters, maar is meer kompak. Die vervaardigingsprototipe handhaaf minder as -21 dB intreeweerkaatsing oor die deurlaatband van 8.5 - 10.5 GHz, asook attenuasie van meer as 50 dB oor die stopband 17 - 31.5 GHz en 30 dB oor 34 - 42 GHz. Die prototipe is ontwerp om 4 kW intree kruindrywing te hanteer in die deurlaatband, en is 130 mm lank. Die metode vereis minimale verstellings tydens volgolf simulasie, en die meetresultate stem goed ooreen met die gesintetiseerde gedrag. 'n Nuwe skuinstandpatroon word ook voorgestel vir wafelyster lters. Vir die harmoniekdemper word transversale bre ewandgleuwe in reghoekige gol eier wat koppel na 'n absorberende newegol eier ondersoek in die teenwoordigheid van staandegolfpatrone in oppervlakstroom. 'n Akkurate stroombaanmodel van 'n gleufkaskade word ontwikkel, en geoptimeer om 'n vereiste intreeweerkaatsing te bewerkstellig in samewerking met 'n arbitr^ere weerkaatsende lter. Deur gebruik te maak van poortparameterdata van die wafelyster lter word 'n 33 mm lange hamoniekdemper ontwikkel wat 'n maksimum intreeweerkaatsing van -12.5 dB oor die band 17 - 21 GHz handhaaf vir kruindrywingsvlakke van tot 1 kW. Goeie ooreenstemming tussen gesintetiseerde en gemete resultate word weereens waargeneem vir die volledige saamgestelde struktuur.

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Tingleff, Jens. "Current Mode Wave Active Filters : a topology for high frequency integrated filters." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337669.

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Guo, Mofei. "Multi-passband filters and tunable filters design based on coupled resonator circuits." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6859/.

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This thesis investigates multi-passband and tunable microwave filters, it includes a new generalised design technique for multi-passband filters and a new coupling tuning structure for tunable waveguide filters. The synthesis technique is an analytical approach and offers very fast solutions to the design once the desired filter specifications are given. The technique calculates the coupling matrix and external Q-factors for a wide range of filter specifications. The centre frequency and bandwidth of each passband, and the number of passbands can all be arbitrarily chosen. To verity the calculations, multi-passband filters are realised by using inverter coupled resonator sections. Two X-band waveguide multi-passband filter examples are given to validate the theory. Besides the innovation in synthesis technique, new designs of fully tunable waveguide filters are also presented. These filters are based on the new coupling tuning structure and a separate frequency tuning structure offering tuning in both centre frequency and bandwidth of the filter. One tunable bandpass filter and one tunable notch filter is implemented in X-band waveguide circuit.

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SEN, SUMIT. "DESIGN OF NONLINEAR FILTERS FOR SIGNAL ESTIMATION AND COMPARISON WITH KALMAN FILTERS." University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1050093518.

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Lakys, Yahya. "Filtres à fréquence agile totalement actifs : théorie générale et circuits de validation en technologie SiGe BiCMOS 0.25μm." Thesis, Bordeaux 1, 2009. http://www.theses.fr/2009BOR13946/document.

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Ce mémoire fait tout d’abord l’état de l’art des filtres reconfigurables (passifs et actifs) pour les radiocommunications. Les différentes architectures de réception sont comparées pour déterminer celles qui sont les mieux adaptées aux récepteurs de type multistandard. Les concepts de radio logicielle et de radio cognitive ainsi que la façon de les mettre en œuvre sont ensuite indiqués afin de souligner l’intérêt d’utiliser des filtres reconfigurables. Les notions de filtres réglables, reconfigurables et agiles qui sont alors comparées illustrent tout l’intérêt des filtres agiles. Une nouvelle théorie qui permet pour la première fois la réalisation de filtres passe bande du second ordre entièrement actifs à fréquence agile est ensuite introduite. Un amplificateur de contre réaction dont le gain est réglable permet de modifier facilement la valeur de la fréquence centrale du filtre obtenu. Cette théorie est ensuite généralisée et ses nouvelles propriétés sont étudiées. Il en résulte alors une plage de réglage de la fréquence beaucoup plus étendue. Des filtres passe bande ont été réalisés en mode courant en technologie SiGe BiCMOS 0.25 µm de STMicroelectroincs à partir de convoyeurs de courant contrôlés (CCCII). Les résultats de simulation obtenus pour ces différents filtres confirment les avantages de cette théorie. Ils montrent ainsi que la généralisation précédente conduit à des structures entièrement actives dont la plage de réglage de la fréquence augmente et la puissance dissipée diminue. Des résultats de mesure obtenus sous pointes pour un filtre passe bande réalisé dans la technologie précédente sont donnés. Ils sont aussi en parfait accord avec cette théorie. Cette nouvelle approche permettra de réaliser des filtres agiles pour les récepteurs multistandard de radiocommunication
In this thesis, we explore the state of the art of reconfigurable filters (passive and active) used in radio-communications. Different receiving architectures are compared to determine the most suitable for multi-standard devices. The concept of software and cognitive radio as well as the means to implement them are indicated in order to highlight the advantage of reconfigurable filters. The concepts of tunable, reconfigurable and agile filters are compared, illustrating the advantage agile ones. A new theory which allows, for the first time, the realization of second order band-pass fully active filters is then introduced. A feedback amplifier with tunable gain allows modifying easily the center frequency of the resulting filter; this theory is then generalized and its new properties are studied. This results in a large frequency tuning range. Current mode band-pass filters are implemented in SiGe BiCMOS 0.25 µm from STMicroelectroincs using current controlled conveyors (CCCII), the simulation results confirm the interest of this theory. They also show that the generalization leads to entirely active structures whose tuning range increases while its power dissipation decreases. The measurements carried out on the fabricated chip are given; they are in perfect agreement with this theory. The new approach allows realizing agile filters for multi-standard radio-communication receivers

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Hol, Jeroen D. "Resampling in particle filters." Thesis, Linköping University, Department of Electrical Engineering, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2366.

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In this report a comparison is made between four frequently encountered resampling algorithms for particle filters. A theoretical framework is introduced to be able to understand and explain the differences between the resampling algorithms. This facilitates a comparison of the algorithms based on resampling quality and on computational complexity. Using extensive Monte Carlo simulations the theoretical results are verified. It is found that systematic resampling is favourable, both in resampling quality and computational complexity.

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Eskiyerli, Mirat Hayri. "Square root domain filters." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.299973.

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Dissertations / Theses on the topic 'Filters'

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