Tesis doctorales DIEC - IEKS Doktoretza tesiak

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Browsing Tesis doctorales DIEC - IEKS Doktoretza tesiak by Author "Arnedo Gil, Israel"

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    High-frequency passive components and filters for future high-capacity space and ground communication systems in a hyper-connected world
    (2023) Ahmad, Jamil; Lopetegui Beregaña, José María; Arnedo Gil, Israel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
    This Ph.D. thesis presents the design and fabrication of microwave filters in microstrip and coaxial technologies. The filters are designed using a novel synthesis technique based on coupled mode theory and inverse scattering techniques, resulting in smooth-profiled filters with improved performance characteristics. These filters are particularly well suited for high-power applications, such as satellite-based communication systems. Satellite RF payloads heavily rely on microwave filters, necessitating robust designs with small footprints and high power handling capabilities for both peak and average power. Traditional filter design methods face limitations when operating across wide frequency bands and achieving sufficient power handling capabilities. The proposed novel synthesis technique offers a general and flexible approach to design smooth-profiled filters, overcoming the drawbacks of conventional design techniques. The core of the novel synthesis technique lies in the coupled mode theory, which characterizes the electromagnetic behavior of non-uniform structures, like smooth-varying microwave filters. The technique involves determining coupling coefficients related to the physical dimensions of the structure through coupled-mode equations. Using this innovative synthesis technique, several smooth-profiled filters are designed in microstrip and coaxial technologies, for different frequency specifications. For microstrip filters, in addition to conventional substrates, non-conventional substrate is also explored. The non-conventional substrate is manufactured layer-by-layer using stereolithography (SLA) with a resin filled with ceramic material. Subsequently, silver nanoparticles are deposited on the ceramic substrate using Aerosol Jet Printing (AJP). The validity of the novel synthesis method and the fabrication technique is thoroughly demonstrated through a comprehensive comparison of theoretical, simulated, and measured results, showing a high degree of agreement between them. Overall, this thesis contributes to the advancement of microwave filter design for satellite communication systems, offering a promising approach to achieve enhanced performance, improved power handling, and reduced manufacturing costs through an innovative synthesis technique and novel fabrication processes.
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    PublicationOpen Access
    New design techniques for telecommunication payloads of space systems suitable for additive manufacturing in the context of large platforms
    (2023) Hussain, Jabir; Lopetegui Beregaña, José María; Arnedo Gil, Israel; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
    In this thesis, microwave filters capable of handling high-power designed using novel synthesis method based on coupled-mode theory and inverse scattering technique and fabricated using metal additive manufacturing (AM) is presented with a view for space-based satellite applications. Microwave filter is one of the key components in a satellite payload system and as such its design and engineering requires careful consideration of various factors such as frequency range, size, weight, and power consumption limitations. The filters designed using classical methods usually suffer when operating in a wide frequency band and have low power handling capability. Thus, in this thesis, the novel synthesis technique which is general and flexible for any passive and causal frequency response is used to design filters having smooth-profile, which provides the advantage of supporting high-power. Such complex structures cannot be easily fabricated using traditional CNC methods and if done will require more time which increases the overall manufacturing cost. Thus, the smooth-profile variation of the filters is also orientated such that it is suitable to be fabricated using additive manufacturing in metal with ease. The coupled-mode theory, on which the synthesis technique is based, is used to characterise the electromagnetic behaviour of a non-uniform structure, such as a smooth-varying microwave filter, in terms of its coupling coefficients which is related through the coupled-mode equations to the physical dimensions of the structure. On the other hand, the inverse scattering technique, such as integral layer peeling method, is used to calculate the coupling coefficients from the target frequency response. Once designed, the filters are fabricated using Selective Laser Melting (SLM) technique which is one of the most commonly used metal-based AM technology. Various prototypes of the microwave filters, in both rectangular waveguide and microstrip technology, in different frequency range are considered and the results of their synthesis and fabrication are compared and analysed with the theoretical background where a high degree of agreement between them suggests the validity of the novel synthesis method and the fabrication technique.
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    PublicationOpen Access
    Synthesis of high-performance smooth-profiled tapers and filters in microstrip and rectangular waveguide technologies
    (2020) Percaz Ciriza, Jon Mikel; Arnedo Gil, Israel; Lopetegui Beregaña, José María; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren
    En esta tesis, los fundamentos teóricos y la formulación de la Teoría de Acoplo de Modos para el análisis y el modelado electromagnético de guías de onda no uniformes son utilizadas para desarrollar diferentes técnicas de síntesis de dispositivos de microondas y de milimétricas que son automáticas e independientes de la tecnología concreta de implementación. En primer lugar, la técnica para sintetizar estructuras EBG óptimas es descrita y revisada en profundidad. Posteriormente, las técnicas generales y exactas de Inverse Scattering de Gel’fand, Levitan, Marchenko (GLM), Continuous Layer Peeling (CLP) e Integral Layer Peeling (ILP) son presentadas en detalle. Estas técnicas de Inverse Scattering, permiten calcular el coeficiente de acoplo para cualquier respuesta monomodo en reflexión objetivo que cumpla con los principios físicos de estabilidad, causalidad y pasividad. Inspirados en estos métodos de síntesis, se proponen novedosas técnicas de diseño de diferentes componentes de microondas como tapers y multiplexores. Además, se propone un método de diseño de filtros paso bajo y paso banda de perfil suave que no presentan bandas de rechazo espurias. La aplicación de esta técnica para el diseño de filtros de alto rechazo en guía de onda rectangular da lugar a estructuras que resultan sumamente apropiadas para ser fabricadas con las novedosas técnicas de fabricación aditiva (AM) en metales. Las diferentes técnicas de diseño propuestas son validadas mediante la realización de varios ejemplos de prácticos de diseño en el rango de microondas en los que se logra alto grado de concordancia entre las respuestas objetivo, simuladas y medidas.