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Deep chemical etching on quartz substrates and integrated passive devicesHuang, Chuan-Yi 29 July 2010 (has links)
The purpose of the thesis is to investigate and the corrosion resistance of the masking materials on quartz substrates in deep chemical etching using NH4HF2 solutions. Masking materials, including Cr/Au, PLA-900 position photoresist, and NPR-2500F negative photoresist were used for test. In the deep etching of the quartz substrates, we observed changes of adhesion of the masking materials. The process parameters obtained from deep etching were used to fabricate quartz resonators. Before etch, the etch masks using Cr/Au thin films were deposited on both sides of the quartz substrates. Cr/Au masking materials were stripped after the etching, and Cr/Au electrodes were deposited by sputtering on both sides of quartz substrates. Finally, the quartz resonators were obtained by dicing. Passive devices, including capacitors and inductors were also fabricated and measured for integrated passive devices, such as band-pass filters.
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Highly Miniaturized Bandpass Filters for Wireless System-in-Package ApplicationsChen, Chien-Hsun 14 March 2012 (has links)
This dissertation studies and implements highly miniaturized bandpass filter designs for wireless System-in-Package (SiP) applications. Based on the coupling matrix synthesis method, the external quality factors and coupling coefficients can be extracted by selecting the proper tapped-line feeding position and coupling spacing in geometrical configuration. Despite their high performance, most conventional microstrip bandpass filter designs require a bulky area for achieving, making them difficult to implement SiP applications. This dissertation first develops a stacked LC resonator and a stacked spiral resonator (SSR) in an embedded passive substrate (EPS) for realizing miniature single- and multi-band bandpass filters. Moreover, multiple transmission zeros created on both sides of each passband provide high stopband roll-off rates. The designed performance and size are comparable to those of low-temperature co-fired ceramic (LTCC) bandpass filters. As another conventional means of implementing RF passive components, the integrated passive device (IPD) process can produce large-value inductors and high-density capacitors, simultaneously. This dissertation fully utilizes the advantages of IPD technology to implement very compact bandpass filter designs with multiple transmission-zero frequencies at stopband by using a high-density wiring planar transformer configuration. Furthermore, due to the fully symmetric geometry, the transformer-coupled bandpass filter can be easily converted into a balun bandpass filter, capable of providing a superior balance performance with a significantly higher common mode rejection ratio (CMRR) level. The electromagnetic (EM) simulation results, as obtained by using Ansys-Ansoft HFSS, agree with the measurement results for all of the proposed designs in this dissertation.
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Étude et minimisation du facteur de qualité des antennes pour de petits objets communicants / Study an optimization of the quality factor of small antennasDiop, Oumy 27 September 2013 (has links)
Actuellement, les objets communicants sans fils occupent une place prépondérante. Pour faciliter leur utilisation, ces objets sont de plus en plus petits et nécessitent de très petites antennes. Cette miniaturisation d’antennes implique forcément une détérioration de leurs performances. La conception d’antennes électriquement petites (AEP) nécessite une très bonne compréhension théorique des mécanismes électromagnétiques mis en jeu notamment quelles limites précises peut-on atteindre pour une AEP étant circonscrive dans un volume donné. Un des paramètres essentiels d’une AEP est son facteur de qualité intrinsèque qui est inversement proportionnel à sa bande passante en impédance. Ainsi, maximiser la bande passante en impédance d’une antenne consiste à minimiser son facteur de qualité. Face à ce problème, de nombreux travaux ont été développés pour déterminer les limites possibles pour des AEP. C’est dans ce cadre que s’inscrit le premier axe de recherche de la thèse : étudier le facteur de qualité d’AEP, afin de déterminer s’il existe des dimensions optimales permettant de s’approcher de ces limites. Le second axe de recherche a consisté à étudier des AEP fonctionnant à 2,45 GHz pour des implants biomédicaux. Celles-ci sont imprimées sur de nouveaux types de substrat pour avoir une meilleure résolution de trace métallique favorisant une réduction de l’encombrement, et une intégration facilitant ainsi les interconnexions avec les frontaux RF. Le challenge consiste à maximiser les performances de ces antennes. Plusieurs prototypes ont été réalisés pour valider les simulations. / Currently, wireless devices play an important role in everyday life. For ease-of-use, these devices are becoming smaller and require very small antennas. However, the size reduction of these antennas necessarily implies a degradation of their performance. Consequently, the design of electrically small antennas (ESA) requires a very good theoretical understanding of the electromagnetic phenomenon that takes place, especially in terms of accurate performance that can be expected for an ESA with given dimensions. An important parameter of an ESA is its intrinsic quality factor since it is inversely proportional to its impedance bandwidth. Indeed, maximizing the matching bandwidth of an antenna consists in minimizing its quality factor. Facing this problem, many researches have been developed to determine the possible limits of the quality factor of ESA. The first research axis of this thesis is to study the quality factor of ESA to determine whether optimal dimensions exist to approach the fundamental quality factor limits. The second part of the thesis studies miniature antennas for biomedical implants operating at 2.45 GHz. These antennas are printed on a specific microelectronic substrate to ensure a better resolution in terms of metallic traces in order to reduce the size and allow easier integration to facilitate interconnections with RF front-end. The challenge consists in maximizing the performance of these antennas. The presented results are supported by means of electromagnetic models and simulations on one hand. Also, several prototypes are fabricated to validate these simulations.
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Electromagnetic simulation and design of etched diffraction grating demultiplexersSong, Jun January 2008 (has links)
Among various planar lightwave circuits for multiplexing/demultiplexing in an optical communication system, etched diffraction gratings (EDGs) have shown great potential due to their compactness and high spectral finesse. Conventional numerical methods for grating simulation cannot be used to simulate an EDG demultiplexer of large size (in terms of the wavelength). In the present thesis, the polarization-dependent characteristics of an EDG demultiplexer are analyzed with a boundary element method (BEM) for both an echelle grating coated with a metal and a dielectric grating with total internal reflection (TIR) facets. For EDGs with metal-coated facets, we use a more effective method, namely, method of moments (MoM). Futhermore, a fast simulation method for EDGs with TIR facets is presented based on the Kirchhoff–Huygens principle and the Goos-Hänchen shift. This simple method has a good agreement with a BEM over a wide range of practical parameters of the device. Several novel designs are presented in order to improve the performances of EDGs. (1) By making some appropriate roughness on the surface of the shaded facets, the PDL of the demultiplexer can be effectively reduced over a large bandwith. (2) For EDGs based on Si nanowire structures, we compensate the polarization-dependent wavelength dispersion (PDλ) in the whole operational spectrum by introducing a polarization compensation area in its free propagation region. (3) An EDG demultiplexer with suppressed sidelobe is designed. The designed EDG demultiplexer can give a crosstalk as small as 50 dB in theory. (4) By chirping the diffraction order for each facet, we minimize the envelope intensity for the other adjacent diffraction orders to achieve a negligible return loss in a large spectral width. (5) A design for EDG demultiplexers is presented to obtain both large grating facets and a larger free spectral range (FSR) using the optimal chirped diffraction orders for different facets. The influences of the fabrication errors (e.g., rounded effect, surface roughness and point defect in the waveguide) on the performance (such as the insertion loss, the polarization dependent loss and the chromatic dispersion) of an EDG demultiplexer are also analyzed in detail. Silicon nanowire waveguides and related EDGs are studied. An EDG demultiplexer with 10 nm spacing is finally fabricated and characterized. / QC 20100910
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Reconfigurable Devices using Liquid Crystal at Microwave Frequencies in Substrate Integrated WaveguideSánchez Marín, Juan Rafael 02 December 2019 (has links)
[ES] La cantidad de servicios de telecomunicación se ha incrementado signiticativamente en las últimas décadas. El uso de teléfonos inteligentes, así como el Internet de las Cosas, está generando una saturación del espectro electromágnetico. Por tanto, los requisitos de los sistemas de microondas han cambiado para adaptarse a estos nuevos avances.
Para satisfacer estas necesidades, se busca el desarrollo de dispositivos de bajo coste, volumen, peso y consumo. Además, interesa que sean espectralmente eficientes y fácilmente integrables con otros dispositivos. Entre todos los dispostivos de microondas, los filtros son elementos clave dentro de los sistemas de comunicaciones móviles e inalámbricas. Es por ello que el diseño de filtros que cumplan con los requisitos mencionados se ha convertido en un tema de gran interés. Para dar respuesta a este problema ha surgido la tecnología de Guía de Onda Integrada en Sustrato (Substrate Integrated Waveguide (SIW)), que permite la implementación de filtros con un reducido tamaño y fácilmente integrables con otros dispositivos en tecnología planar. Dicha tecnología presenta unas prestaciones en cuanto a manejo de potencia y pérdidas mejores que la tecnología de circuito impreso (Printed Circuit Board (PCB)), aunque no llegan a ser iguales que las de la guía de onda clásica.
Por otro lado, la saturación espectral también lleva al estudio de filtros con respuestas variables en frecuencia, es decir, que puedan cambiar su frecuencia central y ancho de banda con el fin de adaptarse a las necesidades del sistema.
Por ello, el objetivo general de esta Tesis es el análisis y diseño de nuevos filtros reconfigurables en tecnología integrada. El trabajo empieza con el estudio de los fundamentos de los filtros de microondas hasta llegar al diseño de resonadores reconfigurables en tecnología SIW usando el cristal líquido como material de reconfiguración.
En primer lugar, se ha estudiado la influencia que los cambios en el valor de la permitividad dieléctrica en el interior de las estructuras filtrantes pueden tener en la respuesta de las mismos. En particular, se desarrollan filtros alternando secciones de línea con y sin dieléctrico dentro de una SIW vacía, Empty Substrate Integrated Waveguide (ESIW).
Una vez hecho esto, se procede al estudio de materiales que tengan un valor de permitividad dieléctrica variable de alguna forma. En concreto, se ha realizado la caracterización de diferentes mezclas de cristal líquido a la frecuencia de microondas. Dicho material cambia su valor de permitividad cuando se le aplica un campo eléctrico o magnético.
Dado que para la reconfiguración de la respuesta de los filtros se requiere de una estructura desacoplada en baja frecuencia, es decir, con más de un conductor, se ha desarrollado una estrategia para el desacoplo de la estructuras ESIW, la tecnología Decoupled Empty Substrate Integrated Waveguide (DESIW).
Por último, se han diseñado resonadores en dicha tecnología DESIW, que se han llenado de cristal líquido y aplicado unos campos de polarización, consiguiendo variar su respuesta en frecuencia. Dichos resonadores constituyen el elemento básico para el desarrollo de filtros de microondas. Es por ello que el conocimiento obtenido en la Tesis es una buena base para futuros trabajos esta tecnología que permitan conseguir filtros de altas prestaciones. / [CAT] La quantitat de serveis de telecomunicació s'ha incrementat significativament en les últimes dècades. L'ús de telèfons intel$\cdot$ligents, així com la internet de les coses, està generant una saturació de l'espectre electromagnètic. Per tant, els requisits dels sistemes de microones han canviat per a adaptar-se a aquests nous avanços.
Per a satisfer aquestes necessitats, se cerca el desenvolupament de dispositius de baix cost, volum, pes i consum. A més, interessa que siguen espectralment eficients i fàcilment integrables amb altres dispositius. Entre tots els dispositius de microones, els filtres són elements clau dins dels sistemes de comunicacions mòbils i sense fil. És per això que el disseny de filtres que complisquen els requisits esmentats s'ha convertit en un tema de gran interès. Per a donar resposta a aquest problema ha sorgit la tecnologia de Guia d'Ona Integrada en Substrat (Substrate Integrated Waveguide (SIW)), que permet la implementació de filtres amb una reduïda grandària i fàcilment integrables amb altres dispositius en tecnologia planar. Aquesta tecnologia presenta unes prestacions quant a maneig de potència i pèrdues millors que la tecnologia de circuit imprès (Printed Circuit Board (PCB)), encara que no arriben a ser iguals que les de la guia d'ona clàssica.
D'altra banda, la saturació espectral també porta a l'estudi de filtres amb respostes variables en freqüència, és a dir, que puguen canviar la seua freqüència central i l'amplada de banda amb la finalitat d'adaptar-se a les necessitats del sistema.
Per això, l'objectiu general d'aquesta tesi és l'anàlisi i el disseny de nous filtres reconfigurables en tecnologia integrada. El treball comença amb l'estudi dels fonaments dels filtres de microones, fins a arribar al disseny de ressonadors reconfigurables en tecnologia SIW usant el cristall líquid com a material de reconfiguració.
En primer lloc, s'ha estudiat la influència que els canvis en el valor de la permitivitat dielèctrica a l'interior de les estructures filtrants poden tenir en la resposta d'aquestes. En particular, es desenvolupen filtres que alternen seccions de línia amb dielèctric i sense dins d'una SIW buida, Empty Substrate Integrated Waveguide (ESIW).
Una vegada fet això, es procedeix a l'estudi de materials que tinguen un valor de permitivitat dielèctrica variable d'alguna forma. En concret, s'ha realitzat la caracterització de diferents mescles de cristall líquid a la freqüència de microones. Aquest material canvia el seu valor de permitivitat quan se li aplica un camp elèctric o magnètic.
Atès que per a la reconfiguració de la resposta dels filtres es requereix una estructura desacoblada en baixa freqüència, és a dir, amb més d'un conductor, s'ha desenvolupat una estratègia per al desacoblament d'estructures ESIW, la tecnologia Decoupled Empty Substrate Integrated Waveguide (DESIW).
Finalment, s'han dissenyat ressonadors en aquesta tecnologia DESIW, que s'han omplit de cristall líquid i aplicat uns camps de polarització, i s'ha aconseguit variar la seua resposta en freqüència. Aquests ressonadors constitueixen l'element bàsic per al desenvolupament de filtres de microones. És per això que el coneixement obtingut en la tesi és una bona base per a futurs treballs d'aquesta tecnologia que permeten aconseguir filtres d'altes prestacions. / [EN] The number of telecommunication services has increased significantly in recent decades. The use of smartphones, as well as the Internet of Things, is generating a saturation of the electromagnetic spectrum. Therefore, the requirements of microwave systems have changed to adapt to these new developments and related challenges.
For achieving these needs, the development of devices with low cost, volume, weight and power consumption is sought. In addition, it interests to be spectrally efficient, to offer high performance, and to be easily integrated with other devices. Among all microwave devices, filters are key elements within mobile and wireless communication systems. In this context, the design of filters that meet the aforementioned requirements has become a topic of great interest. For solving this problem, Substrate Integrated Waveguide (SIW) technology has emerged, which allows the implementation of filters with a small size and to be easily integrated with other devices in planar technology. This technology has better power handling and loss performance than Printed Circuit Board (PCB) technology, although they do not have the performance of the classic waveguide counterpart.
On the other hand, the spectral saturation also leads to the study of filters with tunable frequency response, that is, they can change their central frequency and bandwidth, in order to fulfil the changing system requirements.
Therefore, the general objective of this PhD Thesis work is the analysis and design of new reconfigurable filters in integrated technology. The work begins with the study of the basics of microwave filters until the design of reconfigurable resonators in SIW technology, using Liquid Crystal (LC) as reconfiguration material.
Firstly, the influence that the change of the dielectric permittivity value inside the filtering structures have on the frequency response has been studied. Particularly, filters have been obtained by alternating line sections with and without dielectric material inside an empty SIW (Empty Substrate Integrated Waveguide (ESIW)).
Once this is done, it is proceed to the study of materials that have a variable dielectric permittivity value. Specifically, the characterization of different LC mixtures at microwave frequencies has been carried out. This material changes its permittivity value when an electric or magnetic bias field is applied.
A low-frequency decoupled structure is required for the reconfiguration of filters, that is, structures with more than one conductor. For that, a strategy for decoupling ESIW structures has been developed, i.e, the Decoupled Empty Substrate Integrated Waveguide (DESIW) technology.
Finally, some resonators have been designed in DESIW technology, which have been filled with LC. The use of LC allows to tune their frequency response. These resonators are basic elements for the development of microwave filters. So that, the knowledge obtained in this Thesis work is a good basis for future works in this technology that allow for achieving high performance filters. / Sánchez Marín, JR. (2019). Reconfigurable Devices using Liquid Crystal at Microwave Frequencies in Substrate Integrated Waveguide [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/132183 / TESIS
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Integrated Magnetic Components for RF ApplicationsHussaini, Sheena 03 June 2015 (has links)
No description available.
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Towards Industrial Fabrication of Electronic Devices and Circuits by Inkjet Printing TechnologyMitra, Kalyan Yoti 09 June 2021 (has links)
Printing since many years has been a well-known high throughput technology for producing replications of graphic arts entities (texts, images, aesthetics, gloss and physical impressions) over large varieties of substrates which are dedicated for various needful applications like newspapers, magazines, posters, official documents, packages, braille, textiles, decorative articles and many more. Due to the fact, that printing is a liquid-solution based replication process, where basic ink and substrate are needed, it is now not only limited to printing of graphic arts. Whenever an ink is deposited over a defined substrate and the process can be multiplied, it can be termed as printing and once the final product contains a functionality other than graphic arts application, it can be called as “Printed Functionality”. Some examples for printed functionalities can be found in the following fields: A. Printed electronics (using inks having electronic properties); B. Printed micro-fluidics (using inks having polymeric and elastic properties for directive purposes); C. 3-Dimensional printing (using inks containing binding properties for developing three dimensional structures); D. Printed photonics (using inks having self-assembling properties for building-up symmetric micro-structures); E. Printed pyroelectrics (using inks containing thermally flammable properties); F. Printed ceramics (using inks with ceramic particles) and G. Printed optics and functional surfaces (using inks with transparency, absorbency and reflective properties). All these mentioned applications require functional inks which in turn exhibits some physical-chemical properties e.g. particle size, particle loading, fluid’s rheological properties etc. These properties determine the feasibility of the material’s deposition (in this case the functional inks) with a suitable printing technology. The inkjet printing technology among others has several advantages such as contactless deposition processability, digitalization (batch size one & turn-over time zero), user defined customization and adaptation, industrial relevance, minimal ink demand for R&Ds, freedom of substrate regularity and µm-scale print accuracy etc. Some of the imminent players in the inkjet printing technology market are Canon, Kodak, Hewlett Packard, Fujifilm Dimatix, Konica Minolta and XAAR. They provide print solutions from small to industrial scale printheads, printers, equipments and accessories for the realization of huge variety of application ideas. The inkjet is a versatile, but yet matured technology which finds its use in various application areas e.g. home office documentation, large format posters, variable data printing, security printing, textile printing, wallpapers, household articles, curved surfaces like bottles, printing over edible items, printing of elevated surfaces etc. And, hence there are several literatures published which show the use of the inkjet printing technology in the development of products for printed electronics. Some of the common examples are development of passive and active devices e.g. capacitors, resistors, thin-film-transistors, photovoltaics, sensors, circuits like logic gates for electronic switching, device arrays for detection purposes, point of care health applications, energy harvesting applications etc. But, the exploitation of the inkjet technology has not been intense enough to declare the industrial relevance of the technology to be utilized as a fabrication tool in the market. Meanwhile, all the researchers around the globe aim at a single goal, which is the development of “Proof of Concept” devices and applications. Thus, here in this dissertation the implementation of the inkjet printing technology as a digital fabrication tool is exploited to manufacture and up-scale the printed electronic products, which can show an industrial relevance to the commercial market. The main motivation why printed electronics is in great demand (scientific point of view) and has intensely emerged in the last decades, is because of the primary challenges faced in the fabrication process steps of the µ-electronics society. It is know that the classically fabricated µ-electronic products are in the market since long time due to their high reliability, consistent performance and defined applications in circuitry. But, what cannot be ignored is the involved fabrication steps promote several demerits such as the in-flexibility towards the fabrication process, material wastage, in-ability to up-scale into larger areas and huge quantities, and physical rigidity. Some of these mentioned problems are commonly seen e.g. spin coating, chemical vapor-phase deposition, physical vapor-phase deposition, atomic layer deposition and sputtering fabrication technologies. In this present dissertation, on the contrary, the challenges linked with the manufacturing process of the µ-electronic devices using the inkjet technology are focused and attempts are made to counteract them. Some of the foreseen challenges are: A. process workflow adaptation in device manufacturing; B. validation and evaluation of device performance; C. industrializing the inkjet technology (manufacturing µ-electronics in massive quantities); D. evaluating the fabrication yield of printed devices; D. Generating statistics regarding reliability and scalability; and E. demonstrating tolerances in electronic performances. These are definitely the challenges which must be overcome, and these key research points are addressed in the dissertation.
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Development of Non-Conventional Microwave Devices Based on Substrate-Integrated Technology for Advanced ApplicationsNova Giménez, Vicente 26 February 2024 (has links)
[ES] El uso masivo de los sistemas de comunicaciones inalámbricas y móviles ha tenido un impacto significativo en nuestra sociedad. Estas tecnologías han experimentado una amplia adopción en el mercado, volviéndose totalmente indispensables en nuestro día a día y provocando un aumento notable en la demanda de movilidad y ancho de banda. Esto ha llevado a la rápida aparición de nuevos sistemas de comunicación y a la progresiva saturación del espectro radioeléctrico, lo que conlleva un constante aumento en los requisitos de los sistemas de radiofrecuencia. Como resultado, los dispositivos que forman parte de estos sistemas se ven sometidos a especificaciones cada vez más restrictivas. Estas restricciones se han visto fuertemente incrementadas en las comunicaciones espaciales, donde los nuevos sistemas basados en satélite de alta capacidad y grandes constelaciones fuerzan la reducción de costes a la vez que requieren de altas prestaciones.
Con el fin de satisfacer las crecientes demandas de los sistemas inalámbricos, se busca el desarrollo de dispositivos de comunicación que ofrezcan altas prestaciones a bajo costo. Estos dispositivos también deben ser compactos, ligeros y fáciles de integrar con diversas tecnologías de guiado de ondas (guías de ondas, cables coaxiales y tecnologías planares). En respuesta a estas necesidades, han surgido dos soluciones tecnológicas: los circuitos integrados en sustrato (SIC) y la fabricación aditiva (AM).
La tecnología SIC permite combinar tecnologías de guiado planares y no planares en un mismo sistema, lo que resulta en unas prestaciones híbridas entre ambas tecnologías. Además, ofrece una notable reducción de peso y una gran miniaturización y su naturaleza planar permite una integración nunca vista.
Por otro lado, la fabricación aditiva permite crear dispositivos con geometrías complejas y bajo peso, lo que proporciona menos limitaciones en el diseño. Esto permite el desarrollo de dispositivos con características avanzadas y la integración de los diferentes bloques de una cadena de radiofrecuencia en un único dispositivo, mejorando así las especificaciones del sistema y reduciendo su complejidad.
Tanto la tecnología SIC como la fabricación aditiva son de gran interés para el sector espacial. Sin embargo, la aplicación de estas tecnologías en el agresivo entorno espacial aún no ha sido estudiada. Por ello, el objetivo principal de esta tesis es precisamente investigar la aplicación de estas tecnologías al diseño de dispositivos de microondas para aplicaciones espaciales. Con este estudio, se busca obtener un mayor conocimiento de las capacidades y limitaciones de estas tecnologías en el contexto espacial, y así explorar su potencial para mejorar y optimizar los dispositivos utilizados en este tipo de sistemas.
En primer lugar, se ha llevado a cabo una comparación de diferentes topologías de filtros implementados en tecnología SIC, los cuales han sido sometidos a pruebas ambientales que simulan las condiciones reales de operación en el espacio.
En segundo lugar, se ha estudiado la aplicación de técnicas de fabricación aditivas al desarrollo de dispositivos de microondas. Para ello, se ha desarrollado un novedoso método de metalización y un sistema de integración de filtros de montaje superficial. Con estas tecnologías se han desarrollado una serie de filtros paso banda que han sido sometidos a pruebas de ambiente espacial, incluyendo: ciclado térmico, pruebas de vibración y test de efecto multipactor.
Por último, se ha estudiado el uso de cristal líquido para agregar capacidades de reconfigurabilidad a dispositivos SIC. Se han analizado las características mecánicas y electromagnéticas de estos materiales mediante dos métodos de caracterización basados en elementos resonantes. Además, se ha desarrollado un demostrador tecnológico basado en la tecnología ESICL. / [CA] L'ús massiu dels sistemes de comunicacions sense fils i mòbils ha tingut un impacte significatiu en la nostra societat. Aquestes tecnologies han experimentat una àmplia adopció en el mercat, perquè s'han tornat totalment indispensables en el nostre dia a dia i han provocat un augment notable en la demanda de mobilitat i amplada de banda. Al seu torn, això ha portat a la ràpida aparició de nous sistemes de comunicació i a la progressiva saturació de l'espectre radioelèctric, la qual cosa comporta un constant augment en els requisits dels sistemes de radiofreqüència. Com a resultat, els dispositius que formen part d'aquests sistemes es veuen sotmesos a especificacions cada vegada més restrictives. Aquestes restriccions s'han vist fortament incrementades en les comunicacions espacials.
Amb la finalitat de satisfer les creixents demandes dels sistemes sense fils, se cerca el desenvolupament de dispositius de comunicació que oferisquen altes prestacions a baix cost. Aquests dispositius també han de ser compactes, lleugers i fàcils d'integrar amb diverses tecnologies de guia d'ones (guies d'ones, cables coaxials i tecnologies planar). En resposta a aquestes necessitats, han sorgit dues soluciones tecnològiques: els circuits integrats en substrat (SIC) i la fabricació additiva (AM).
La tecnología SIC permet combinar tecnologies de guiatge planars i no planars en un mateix sistema, la qual cosa resulta en unes prestacions híbrides. A més, ofereix una notable reducció de pes i una gran miniaturització i la seua naturalesa planar permet una integració no vista mai abans.
D'altra banda, la fabricació additiva permet crear dispositius amb geometries complexes i baix pes, la qual cosa proporciona menys limitacions en el disseny. Això permet el desenvolupament de dispositius amb característiques avançades i la integració dels diferents blocs que conformen la cadena de radiofreqüència, que millora així les especificacions del sistema i en redueix la complexitat.
Tant la tecnologia SIC com la de fabricació additiva són de gran interès per al sector espacial. Tanmateix, l'aplicació d'aquestes tecnologies en l'agressiu entorn espacial encara no ha sigut estudiada. Per això, l'objectiu principal d'aquesta tesi és investigar l'aplicació d'aquestes tecnologies en el disseny de dispositius de microones per a aplicacions espacials. A través d'aquest estudi, se cerca obtenir un major coneixement sobre les capacitats i limitacions d'aquestes tecnologies en el context espacial.
En primer lloc, s'ha dut a terme una comparació de diferents topologies de filtres implementats en tecnologia SIC, els quals han sigut sotmesos a proves ambientals que simulen les condicions reals d'operació a l'espai.
En segon lloc, s'ha estudiat l'aplicació de tècniques de fabricació additives al desenvolupament de dispositius de microones. Per a això, s'ha desenvolupat un nou mètode de metal·lització autocatalític i un sistema d'integració de filtres de muntatge superficial. Aquestes tecnologies s'han combinat per a desenvolupar una sèrie de filtres passabanda de muntatge superficial. Finalment, aquests filtres han sigut sotmesos a proves d'ambient espacial, incloent-hi: ciclatge tèrmic, proves de vibració i test d'efecte multipactor.
Finalment, s'ha estudiat l'ús de cristall líquid per a agregar capacitats de reconfigurabilitat a dispositius de microones integrats en substrat. S'han analitzat les característiques mecàniques i electromagnètiques d'aquests materials mitjançant dos mètodes de caracterització basats en elements ressonants. A més, s'ha desenvolupat un demostrador tecnològic basat en la tecnologia ESICL. / [EN] The widespread use of wireless and mobile communication systems has had a significant impact on our society. These technologies have been widely adopted in the market, becoming essential in our daily lives and leading to a notable increase in the demand for mobility and bandwidth. Consequently, new communication systems are rapidly emerging, and the radio frequency spectrum is becoming increasingly crowded, resulting in continuously rising requirements for radio frequency systems. As a result, radio frequency devices are subjected to ever more stringent specifications. These restrictions are particularly heightened in space communications.
To meet the growing demands of wireless systems, there is a need to develop communication devices that offer high performance at a low cost. Additionally, these devices should be compact, lightweight, and easily integrable with various waveguide technologies (waveguides, coaxial cables, and planar technologies). In response to these needs, two technological solutions have emerged: Substrate Integrated Circuits (SIC) and Additive Manufacturing (AM).
SIC technology combines planar and non-planar guiding technologies in a single system, resulting in hybrid performance between both technologies. It significantly reduces weight and miniaturisation, and its planar nature allows for unprecedented integration.
On the other hand, additive manufacturing enables the creation of devices with complex geometries and low weight, providing fewer design limitations. This allows for the development of devices with advanced features and the integration of different blocks of the radio frequency chain, thereby enhancing the performance of the entire system and reducing its complexity.
Both SIC and AM are of great interest to the space sector. However, the application of these technologies in the harsh space environment has not been thoroughly studied. The main objective of this thesis is to investigate the application of these technologies in the design of microwave devices for space applications. This study aims to gain a deeper understanding of the capabilities and limitations of these technologies in the space context and explore their potential for improving and optimising devices used in such systems.
The thesis first involves the design and comparison of different filter topologies implemented using SIC technology, which has been subjected to environmental tests simulating real space operation conditions.
Secondly, the application of additive manufacturing techniques to the development of microwave devices has been studied. For this purpose, a novel metallisation method and a system for surface-mounted filter integration have been developed. These technologies were combined to develop a series of surface-mounted bandpass filters. Finally, these filters were subjected to space environmental tests, including thermal cycling, vibration tests, and multipactor effect tests.
Lastly, the use of liquid crystal to add reconfigurability capabilities to substrate-integrated microwave devices has been investigated. The mechanical and electromagnetic characteristics of these materials have been analysed using two resonant element-based characterisation methods. Additionally, a technological demonstrator based on ESICL technology has been developed. / Nova Giménez, V. (2024). Development of Non-Conventional Microwave Devices Based on Substrate-Integrated Technology for Advanced Applications [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/202844
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