Person:
Iriarte Galarregui, Juan Carlos

person.page.identifierURI

https://academica-e.unavarra.es/handle/2454/49289

Last Name

Iriarte Galarregui

First Name

Juan Carlos

person.page.departamento

Ingeniería Eléctrica, Electrónica y de Comunicación

person.page.instituteName

ISC. Institute of Smart Cities

ORCID

0000-0002-2860-5138

person.page.upna

3696

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Now showing 1 - 10 of 20

Open Access
Remote sensing for plant water content monitoring: a review
(MDPI, 2021) Quemada Mayoral, Carlos; Pérez Escudero, José Manuel; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Santesteban García, Gonzaga; Torres Molina, Nazareth; Iriarte Galarregui, Juan Carlos; Institute of Smart Cities - ISC; Institute for Multidisciplinary Research in Applied Biology - IMAB
Las redes sociales se han convertido en una de las principales fuentes de información, especialmente entre los más jóvenes. Al mismo tiempo, se ha incrementado la producción y circulación de información falsa o fake news a través de las redes. En este contexto, resulta crucial que los jóvenes adquieran estrategias y competencias para realizar una lectura crítica de la información que consumen. Este estudio busca analizar el comportamiento del alumnado de secundaria ante la información falsa y el efecto de una intervención didáctica, realizada online durante la pandemia de la covid-19, cuyo objetivo era que el alumnado desarrollara competencias para detectar noticias falsas. Se trata de una investigación participativa con un diseño de pre-test y post-test. Los resultados muestran que el alumnado incrementó su competencia para identificar algunos tipos de falsedad como la información no probada y la información tergiversada, si bien tuvo problemas para reconocer información descontextualizada o el uso de lenguaje discriminatorio. Las estrategias que más utilizó son la comprobación de datos en internet y el uso de verificadores. Se observaron comportamientos diferenciados entre el alumnado que identificó la información falsa y el que no lo hizo. Las conclusiones apuntan a la necesidad de trabajar en el aula de forma integral, extensiva y transversal la evaluación de la información partiendo de las habilidades que el alumnado ya posee.
Open Access
Surface waves of finite size electromagnetic band gap woodpile structures
(EMW Publishing, 2011) Ederra Urzainqui, Íñigo; Iriarte Galarregui, Juan Carlos; Gonzalo García, Ramón; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This paper studies the surface modes at the interface of finite size Electromagnetic Band Gap (EBG) woodpile structures. The impact of different types of woodpile terminations on the properties of these surface modes is analyzed. For all the studied terminations there exist surface modes which must be taken into account when designing components based on this EBG structure.
Open Access
A water content continuous monitoring of grapevine xylem tissue using a portable low-power cost-effective FMCW radar
(IEEE, 2019) Quemada Mayoral, Carlos; García González, Cebrián; Iriarte Galarregui, Juan Carlos; Marín Ederra, Diana; Gastón Beraza, Diego; Miranda Jiménez, Carlos; Gonzalo García, Ramón; Maestrojuán Biurrun, Itziar; Santesteban García, Gonzaga; Ederra Urzainqui, Íñigo; Agronomia, Bioteknologia eta Elikadura; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Agronomía, Biotecnología y Alimentación; Ingeniería Eléctrica, Electrónica y de Comunicación; Gobierno de Navarra / Nafarroako Gobernua, PI025 VITHZ; Gobierno de Navarra / Nafarroako Gobernua, 0011-1365-2016-000084 RAFF
This paper presents the real-time monitoring of a grapevine’s water content that flows up through the xylem tissue by means of a frequency-modulated continuous-wave (FMCW) radar. The application of an optimization process, based on the super-resolution multiple signal classification (MUSIC) algorithm, has enabled the reduction of the bandwidth required to discern the xylem water content, and thus the operating frequency, achieving a depth resolution of at least 3 mm. This design advantage has resulted in a significant step forward towards a real life application, allowing the use of fully-integrated off-the-shelf components in order to implement a completely portable low-power cost-effective radar at 23.1 GHz with a 3.4 GHz bandwidth. The sensor performance has been evaluated by means of three different experiments: irrigation cycles, day/night cycles and comparison between irrigation cycles at different temperatures. From the experimental results, it is possible to assert that the contactless sensor presented in this work is very sensitive to changes in the plant’s water content, differentiating between daytime and nighttime. In addition, it has been proved that temperature has a noticeable influence over the evapotranspiration, observing negative drying slopes of 5.62 mV/cycle and 6.28 mV/cycle at 23ºC and 26ºC respectively.
Open Access
New hexagonal CORPS-BFN for multibeam antenna applications
(IEEE, 2020) Biurrun Quel, Carlos; Montesano, Antonio; Ederra Urzainqui, Íñigo; Iriarte Galarregui, Juan Carlos; Río Bocio, Carlos del; Ingeniaritza Elektrikoa, Elektronikoaren eta Telekomunikazio Ingeniaritzaren; Institute of Smart Cities - ISC; Ingeniería Eléctrica, Electrónica y de Comunicación
This work presents a new topology of a Coherently Radiating Periodic Structure - Beam Forming Network (CORPS-BFN) and its application for multibeam systems. A unit cell, consisting of a transition from a coaxial input to an intersection of three strip-lines with an angular span of 120 degrees, is proposed and analysed. A periodical replication of the cell gives rise to a uniform layer, allowing a proper matching of the ports of the network. Stacked layers allow in-phase propagation and distribution of the energy through the structure, increasing the number of output ports with each layer.
Embargo
Experimental validation of a Ku-band dual circularly polarized metasurface antenna
(IEEE, 2018) Tellechea Pereda, Amagoia; Caminita, Francesco; Martini, Enrica; Ederra Urzainqui, Íñigo; Teniente Vallinas, Jorge; Iriarte Galarregui, Juan Carlos; Gonzalo García, Ramón; Maci, Stefano; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica
The experimental validation of a Ku-band dual circularly polarized (CP) broadside-beam metasurface (MTS) antenna is presented. A radially modulated anisotropic single layer MTS has been synthesised employing sub-wavelength elliptical slotted metallic patches printed on top of a thin Arlon grounded substrate. In the structure, two decoupled phasematched transverse magnetic and transverse electric surface waves (SWs) are excited, which interact with the modulated surface leading to a CP broadside radiation. Two different orthomode transducers have been designed to excite the SWs with orthogonal polarization and equal amplitude. The first feeding system is composed of a metallic stepped septum inside an airfilled square waveguide. A conical section is included to match the output port of the square waveguide with the terminal, dielectric filled circular waveguide. The second feed is much more compact and efficient and it is composed of a circular waveguide completely filled by a dielectric. Depending on the input port excited on the feeds, two TE11 modes are excited with ±90° phase shift, which determine the right-hand or left-hand sense of the broadside beam generated by the MTS. Manufacturing details of the MTS and excitations are given and the measurements are compared with the simulation results. Finally, conclusions are drawn.
Open Access
Hexagonal CORPS-BFN to feed OLAF SAR instrument
(IEEE, 2021) Biurrun Quel, Carlos; Iriarte Galarregui, Juan Carlos; Ederra Urzainqui, Íñigo; Río Bocio, Carlos del; Institute of Smart Cities - ISC
The concept of Coherently Radiating Periodic Structures-based Beam Forming Networks is applied to feed OLAF (OverLapped SubArray Fed) antenna for SAR Instrument at L-Band. The proper feeding of this system requires the multiple beams to be highly overlapped, and that is generated by a CORPS-BFN using a new 4-port Gysel power combiner/divider implemented in a suspended stripline technology. The network provides high isolation between inputs/outputs, low insertion loss, great return loss and the desired ovelapping of the different beams.
Open Access
Assessment of mm-wave high resolution inverse SAR imaging both with compact and sparse data
(IEEE, 2023) Iqbal, Muhammad Amjad; Anghel, Andrei; Datcu, Datcu; Ederra Urzainqui, Íñigo; Iriarte Galarregui, Juan Carlos; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute of Smart Cities - ISC
Inverse synthetic aperture radar (ISAR) provides images of objects that are rotated with respect to the radar. An efficient image-focusing algorithm is required to generate ISAR images from the echoes of the raw data. In this study, a monostatic model was deployed to collect radar backscattering data in the millimeter (mm) wave band (67-110 GHz) using targets with circular, rectangular, and non-canonical shapes. The ISAR experiments were performed to assess the imaging performance of the three methods. The ISAR image reconstruction implemented in the wave-number (¿ - k) domain solves the target reflectivity and allows the target to be close to the radar. This shows that the mm-wave radar can achieve a sufficient resolution in the range and azimuth dimensions. Finally, we compared the results with those of spherical wavefront compensation (SWFC) and back-projection (BP) methods. The efficiencies of the three methods were tested using compressible data with wavelet-decomposition-based sparse measurements. To demonstrate the performance of the given methods, the point spread function (PSF) for the impulse response of the mm-wave wire was computed. There is a trade-off: the ¿ - k domain loses resolution compared to the SWFC and BP methods but can obtain a satisfactory image at a lower computational cost.
Open Access
Terahertz time domain spectroscopy allows contactless monitoring of grapevine water status
(Frontiers Media, 2015) Santesteban García, Gonzaga; Palacios Horcajada, Inés; Miranda Jiménez, Carlos; Iriarte Galarregui, Juan Carlos; Royo Díaz, José Bernardo; Gonzalo García, Ramón; Producción Agraria; Nekazaritza Ekoizpena; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Gobierno de Navarra / Nafarroako Gobernua, IIM14244.RI1
Agriculture is the sector with the greatest water consumption, since food production is frequently based on crop irrigation. Proper irrigation management requires reliable information on plant water status, but all the plant-based methods to determine it suffer from several inconveniences, mainly caused by the necessity of destructive sampling or of alteration of the plant organ due to contact installation. The aim of this work is to test if terahertz (THz) time domain reflectance measurements made on the grapevine trunk allows contactless monitoring of plant status. The experiments were performed on a potted 14-years-old plant, using a general purpose THz emitter receiver head. Trunk THz time-domain reflection signal proved to be very sensitive to changes in plant water availability, as its pattern follows the trend of soil water content and trunk growth variations. Therefore, it could be used to contactless monitor plant water status. Apart from that, THz reflection signal was observed to respond to light conditions which, according to a specifically designed girdling experiment, was caused by changes in the phloem. This latter results opens a promising field of research for contactless monitoring of phloem activity.
Open Access
Dual circularly polarized broadside beam metasurface antenna
(IEEE, 2016) Ederra Urzainqui, Íñigo; Tellechea Pereda, Amagoia; Caminita, Francesco; Martini, Enrica; Iriarte Galarregui, Juan Carlos; Gonzalo García, Ramón; Maci, Stefano; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
This paper presents the design of a modulated metasurface (MTS) antenna capable to provide both righthand (RH) and left-hand (LH) circularly polarized (CP) boresight radiation at Ku-band (13.5 GHz). This antenna is based on the interaction of two cylindrical-wavefront surface wave (SW) modes of transverse electric (TE) and transverse magnetic (TM) types with a rotationally symmetric, anisotropic-modulated MTS placed on top of a grounded slab. A properly designed centered circular waveguide feed excites the two orthogonal (decoupled) SW modes and guarantees the balance of the power associated with each of them. By a proper selection of the anisotropy and modulation of the MTS pattern, the phase velocities of the two modes are synchronized, and leakage is generated in broadside direction with two orthogonal linear polarizations. When the circular waveguide is excited with two mutually orthogonal TE11 modes in phase–quadrature, an LHCP or RHCP antenna is obtained. This paper explains the feeding system and the MTS requirements that guarantee the balanced conditions of the TM/TE SWs and consequent generation of dual CP boresight radiation.
Open Access
EBG superstrate antenna for WAAS bands
(2008) Osés de León, Ángel; Iriarte Galarregui, Juan Carlos; Ederra Urzainqui, Íñigo; Gonzalo García, Ramón; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
Multiband antennas can simplify considerably the complexity of receivers and transmitters, reducing the size and the mass of the conventional configurations. On the other hand, applications with high directivity requirements need array designs to comply with the directivity specifications using conventional technology. EBG superstrate designs have been satisfactory applied to single band applications using a single EBG superstrate layer. The number of number of radiating elements of conventional technology designs are considerably reduced when using EBG technology. Dual band configurations have also been designed in a single layer, but when working frequencies are too close a second EBG layer is needed. A dual layer EBG superstrate which can easily be adjusted to the desired operational frequencies is presented. The design has been realized to comply with the navigation antenna requirements of Wide Area Augmentation system (WAAS) application in L1 and L2 bands.