• Amorphous glass-coated ferromagnetic wires in microwave engineering 

      Liberal Olleta, Íñigo Upna Orcid (2013)   Tesis doctoral / Doktoretza tesia  OpenAccess
      En esta tesis se ha estudiado el uso de hilos ferromagnéticos recubiertos de vidrio en ingeniería de microondas. Para este fin, se han formulado modelos analíticos y equivalentes circuitales de la interacción entre un ...
    • Bulk optical of potato flesh in the 500 – 1900 nm range 

      López Maestresalas, Ainara Upna Orcid; Aernouts, Ben; Van Beers, Robbe; Arazuri Garín, Silvia Upna Orcid; Jarén Ceballos, Carmen Upna Orcid; Baerdemaeker, Josse de; Saeys, Wouter (Springer US, 2015)   Artículo / Artikulua  OpenAccess
      In this study, the optical properties of potato flesh tissue were estimated using double-integrating sphere (DIS) measurements combined with an inverse adding-doubling (IAD) light propagation model. Total reflectance, ...
    • Error in radar-derived soil moisture due to roughness parameterization: an analysis based on synthetical surface profiles 

      Lievens, Hans; Vernieuwe, Hilde; Álvarez-Mozos, Jesús Upna Orcid; Baets, Bernard de; Verhoest, Niko E. C. (MDPI, 2009)   Artículo / Artikulua  OpenAccess
      In the past decades, many studies on soil moisture retrieval from SAR demonstrated a poor correlation between the top layer soil moisture content and observed backscatter coefficients, which mainly has been attributed ...
    • Evaluating noise in passive beam forming networks for multibeam applications 

      Biurrun Quel, Carlos Upna Orcid; Río Bocio, Carlos del Upna Orcid (Elsevier, 2023)   Artículo / Artikulua  OpenAccess
      In this work, we identify that the analysis in terms of noise of multibeam passive beam forming networks requires a proper formulation, in order not to overestimate the noise generated by the network. We show that the ...
    • Hybrid computational techniques: electromagnetic propagation analysis in complex indoor environments 

      Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Falcone Lanas, Francisco Javier Upna Orcid; Janaswamy, Ramakrishna (IEEE, 2019)   Artículo / Artikulua  OpenAccess
      In this article, we compare deterministic methodologies for characterizing channel behavior in heterogeneous and composite scenarios. These techniques include one that combines a 3D ray launching (RL) approach based on ...
    • A hybrid ray launching-diffusion equation approach for propagation prediction in complex indoor environments 

      Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Falcone Lanas, Francisco Upna Orcid; Janaswamy, Ramakrishna (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      A novel and efficient deterministic approach to model radio wave propagation channels in complex indoor environments improving prediction accuracy is proposed. This technique combines a 3-D Ray Launching algorithm based ...
    • Influence of surface roughness measurement scale on radar backscattering in different agricultural soils 

      Martínez de Aguirre Escobar, Alejandro Upna Orcid; Álvarez-Mozos, Jesús Upna Orcid; Lievens, Hans; Verhoest, Niko E. C. (IEEE, 2017)   Artículo / Artikulua  OpenAccess
      Soil surface roughness strongly affects the scattering of microwaves on the soil surface and determines the backscattering coefficient (σ 0 ) observed by radar sensors. Previous studies have shown important scale issues ...
    • Influence of surface roughness spatial variability and temporal dynamics on the retrieval of soil moisture from SAR observations 

      Álvarez-Mozos, Jesús Upna Orcid; Verhoest, Niko E. C.; Larrañaga, Arantzazu Upna; Casalí Sarasíbar, Javier Upna Orcid; González de Audícana Amenábar, María Upna Orcid (MDPI, 2009)   Artículo / Artikulua  OpenAccess
      Radar-based surface soil moisture retrieval has been subject of intense research during the last decades. However, several difficulties hamper the operational estimation of soil moisture based on currently available ...
    • A multipolar analysis of near-field absorption and scattering processes 

      Liberal Olleta, Íñigo Upna Orcid; Ederra Urzainqui, Íñigo Upna Orcid; Gonzalo García, Ramón Upna Orcid; Ziolkowski, Richard W. (IEEE, 2013)   Artículo / Artikulua  OpenAccess
      A multipolar formulation is adopted to investigate the absorption and scattering processes involved in near-field interactions. This approach allows one to determine the upper bounds for the absorbed and radiated powers ...
    • A radio channel model for D2D communications blocked by single trees in forest environments 

      Picallo Guembe, Imanol Upna Orcid; Klaina, Hicham Upna; López Iturri, Peio Upna Orcid; Aguirre Gallego, Erik Upna Orcid; Celaya Echarri, Mikel Upna Orcid; Azpilicueta Fernández de las Heras, Leyre Upna Orcid; Eguizábal Garrido, Alejandro; Falcone Lanas, Francisco Javier Upna Orcid; Alejos, Ana (MDPI, 2019)   Artículo / Artikulua  OpenAccess
      In this paper we consider the D2D (Device-to-Device) communication taking place between Wireless Sensor Networks (WSN) elements operating in vegetation environments in order to achieve the radio channel characterization ...
    • Remote (250 km) fiber Bragg grating multiplexing system 

      Fernández Vallejo, Montserrat Upna; Rota Rodrigo, Sergio Upna; López-Amo Sáinz, Manuel Upna Orcid (MDPI, 2011)   Artículo / Artikulua  OpenAccess
      We propose and demonstrate two ultra-long range fiber Bragg grating (FBG) sensor interrogation systems. In the first approach four FBGs are located 200 km from the monitoring station and a signal to noise ratio of 20 dB ...

      El Repositorio ha recibido la ayuda de la Fundación Española para la Ciencia y la Tecnología para la realización de actividades en el ámbito del fomento de la investigación científica de excelencia, en la Línea 2. Repositorios institucionales (convocatoria 2020-2021).
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