Comunicaciones y ponencias de congresos DIEE - IEES Biltzarretako komunikazioak eta txostenak

Permanent URI for this collection

http://hdl.handle.net/2454/10498

Browse

Now showing 1 - 20 of 206

Open Access
Alimentadores gaussianos en guía de onda rectangular
(1999) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
A new and efficient design of a rectangular corrugated waveguide mode converter, from TE10 mode in a smooth rectangular monomode waveguide to HE11 mode in a corrugated rectangular waveguide, is proposed. The main idea is the application of Gaussian design techniques, described in the given references, previously applied in circular waveguides. By using these techniques compact and very efficient components are obtained. The obtained far field pattern is rather good as illuminator of square or rectangular parabolic reflectors, with very low sidelobes and crosspolarisation levels, avoiding the use of a rectangular to circular waveguide converter.
Open Access
All fiber interferometer for ice detection
(Optica Publishing Group, 2018) Arozarena Arana, Jesús Antonio; Socorro Leránoz, Abián Bentor; Del Villar, Ignacio; Díaz Lucas, Silvia; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC
This work presents an etched single-mode - multimode - single-mode structure that detects the solid-to-liquid change of state of the water due to an increased refractive index sensitivity within the 1.308 - 1.321 RIU range
Open Access
All-metallic ε-near-zero (ENZ) lens based on ultra-narrow hollow rectangular waveguides: experimental results
(IEEE, 2014) Orazbayev, Bakhtiyar; Torres Landívar, Víctor; Pacheco-Peña, Víctor; Falcone Lanas, Francisco; Teniente Vallinas, Jorge; Beruete Díaz, Miguel; Sorolla Ayza, Mario; Navarro Cía, Miguel; Engheta, Nader; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Here we perform numerical and experimental investigation of plano-concave all-metallic ε-near-zero (ENZ) lens with operational frequency f = 144 GHz. The ENZ lens is achieved by stacking an array of narrow hollow rectangular waveguides working near cut-off frequency. Focusing and radiation properties are numerically analyzed and measured. The enhancement of 5.61 dB and directivity of 17.6 dBi are shown. Good agreement between experimental and numerical results is demonstrated.
Open Access
Análisis de efecto de un superestrato left-handed en la apertura de una guía rectangular
(2005) Sáenz Sáinz, Elena; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper, results showing the experimental verification of the gain improvement of a rectangular waveguide antenna when a left-handed material (LHM) is used as superstrate are presented. The improvement has been characterized by means of measuring the increase of transmission (S21 parameter) obtained when this LHM is placed between two open-ended rectangular waveguide antennas. An average increase of transmission of about 6.5 d.B has been obtained. Besides, improvements in the radiation patterns of a rectangular waveguide with a LH superstrate are analyzed. An enhancement of 3.5 dB in the directivity and a reduction of 15 dB in the back radiation have been obtained.
Open Access
Análisis del comportamiento de esquemas de modulación adaptativos en LTE
(2009) Torres Landívar, Víctor; Esparza Alfaro, Fermín; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, the behaviour of several modulation schemes used in 3GPP R8 or Long Term Evolution (LTE) Systems is analyzed. In order to increase the capacity of future mobile networks, high order modulation schemes like 64-QAM are envisaged, which have more stringent Signal-to-Noise restrictions. System simulation results for various modulation schemes regarding Error Vector Magnitude (EVM) values and constellation behaviour are obtained, showing dependence of quality degradation with bit rate, interference ratio and relative constellation position of the symbols. These results, related to constellation behaviour, can aid in the future design of high data rate mobility systems based on LTE.
Open Access
Analysis and synthesis of vibrato in lyric singers
(2002) Arroabarren Alemán, Ixone; Carlosena García, Alfonso; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper two aspects of the vibrato signal characterisation are presented. First, an analysis method, which breaks down the musical signal into its different partials, and decomposes them into two separate contributions: AM and FM. This allows an objective characterization of the vibrato according to musical parameters. Second, a procedure for vibrato synthesis is proposed, based on the previous analysis. Even though the results of the synthesis are not fully satisfactory, they shed new light on the vibrato modeling.
Open Access
Analysis of bluetooth-based wireless sensor networks performance in hospital environments
(MDPI, 2016) López Iturri, Peio; Led Ramos, Santiago; Aguirre Gallego, Erik; Azpilicueta Fernández de las Heras, Leyre; Serrano Arriezu, Luis Javier; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a method to analyze the performance of Bluetooth-based Wireless Sensor Networks (WSN) deployed within hospital environments is presented. Due to the complexity that this kind of scenarios exhibit in terms of radio propagation and coexistence with other wireless communication systems and other potential interference sources, the deployment of WSNs becomes a complex task which requires an in-depth radio planning analysis. For that purpose, simulation results obtained with the aid of an in-house developed 3D Ray Launching code are presented. The scenarios under analysis are located at the Hospital of Navarre Complex (HNC), in the city of Pamplona. As hospitals have a wide variety of scenarios, the analysis has been carried out in different zones such as Boxes, where different medical sensors based on Bluetooth communication protocol have been deployed. The simulation results obtained have been validated with measurements within the scenario under analysis, exhibiting Bluetooth-based WSNs performance within hospital environments in terms of coverage/capacity relations. The proposed methodology can aid in obtaining optimal network configuration and hence performance of Bluetooth-based WSNs within medical/health service provision environments.
Open Access
Analysis of radio wave propagation for ISM 2.4GHz wireless sensor networks in inhomogeneous vegetation environments
(2014) Azpilicueta Fernández de las Heras, Leyre; López Iturri, Peio; Aguirre Gallego, Erik; Astrain Escola, José Javier; Villadangos Alonso, Jesús; Falcone Lanas, Francisco; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Ingeniería Matemática e Informática; Matematika eta Informatika Ingeniaritza
The use of wireless networks has been extended in an exponential growing due to the improvement in terms of battery life and low consumption of the devices. However, it is highly important to conduct previous radio propagation analysis when deploying a wireless sensor network. These studies are necessary to perform an estimation of the range coverage, in order to optimize the distance between devices in an actual network deployment. In this work, the radio channel characterization for ISM 2.4GHz Wireless Sensor Networks (WSN) in an inhomogeneous vegetation environment has been analyzed. The impact of topology as well as morphology of the environment is assessed by means of an in-house developed 3D Ray Launching code, to emulate the realistic operation in the framework of the scenario. Experimental results gathered from a measurements campaign conducted by deploying a ZigBee Wireless Sensor Network, are analyzed and compared with simulations in this paper. The scenario where this network is intended to operate is a combination of buildings and diverse vegetation species. To gain insight in the effects of radio propagation, a simplified vegetation model has been developed, considering the material parameters and simplified geometry embedded in the simulation scenario. The use of deterministic tools can aid to know the impact of the topological influence in the deployment of the optimal Wireless Sensor Network in terms of capacity, coverage and energy consumption, making the use of these systems attractive for multiple applications in inhomogeneous vegetation environments.
Open Access
Analysis of surface-plasmon-like modes under an engineering perspective
(2011) Navarro Cía, Miguel; Beruete Díaz, Miguel; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this communication we show how one can exploit equivalent circuits to analyze surface-plasmon-like modes (slit and hole arrays, Sievenpiper mushrooms and coaxial hole arrays) and to propose new designs with outstanding features.
Open Access
Antena corrugada con perfil gaussiano de gran ancho de banda
(2001) Teniente Vallinas, Jorge; Gonzalo García, Ramón; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
En este trabajo se presenta el diseño de una antena de bocina corrugada con más de un 40% de ancho de banda. Los patrones de radiación medidos coinciden muy bien con los simulados. Esta antena se puede usar en aplicaciones que requieran un gran ancho de banda con bajos lóbulos laterales (< -28 dB), baja polarización cruzada (< -30 dB) y con requerimientos en potencia reflejada no demasiado restrictivos (< -15 dB).
Open Access
Antenas de bocina optimizadas para acoplar modos gaussianos de orden superior
(1995) Río Bocio, Carlos del; Gonzalo García, Ramón; Sorolla Ayza, Mario; Thumm, Manfred; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The concept of higher order free space modes, gaussian-like beam modes can be applied to efficiently transport the power generated by a gyrotron for technological applications. Waveguide modes can be coupled properly to higher order gaussian modes. These modes can be guided by an optimized higher order beam waveguide to the final experiment. A family of optimized non linear horn antennas is investigated in order to maximize the coupling between the guided output modes of a technological gyrotron and the free space modes. The numerical computations show very favourable coupling to higher order gaussian modes, with a conversion effiencies of about 99.8%.
Open Access
An antibacterial surface coating composed of PAH/SiO2 nanostructurated films by Layer by Layer
(2009) Urrutia Azcona, Aitor; Rivero Fuente, Pedro J.; Ruete Ibarrola, Leyre; Goicoechea Fernández, Javier; Matías Maestro, Ignacio; Arregui San Martín, Francisco Javier; Ingeniaritza Elektrikoa eta Elektronikoa; Institute of Smart Cities - ISC; Ingeniería Eléctrica y Electrónica; Gobierno de Navarra / Nafarroako Gobernua
In this article we propose a novel antibacterial coating composed of SiO2 and the polymer Poly(allylamine hydrochloride) (PAH) on glass slides by the technique Layer-by- Layer (LbL)1. This technique has already used in previous works, and it has the advantage that it allows to control the construction of nanosized and well organized multilayer films. In this work, the new nanotexturized LbL SiO2 surface acts as antibacterial agent. The fabricated coatings have been tested in bacterial cultures of genus Lactobacillus to observe their antibacterial properties.
Open Access
ASTRA 3B horn antenna design
(2010) Teniente Vallinas, Jorge; Río Bocio, Carlos del; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The ASTRA 3B satellite includes 60 Ku-band state-of-the- art transponders and 4 Ka-band transponders. The spacecraft have been designed for the distribution of both direct-to-home (DTH) broadcast services and two way broadband services across Europe. After Astra 2B and Astra 1M, Astra 3B is the third Astra satellite to be built by ASTRIUM. Two different horn antennas, for Ku- and Ka-bands, were designed with very stringent requirements as it is usually required for space applications. For the horns the cross-polar levels should be below -45 dB, and the return loss below -30dB for all frequency bands. Normally the horn aperture is fixed by the required illumination of the reflector edges, so it is difficult to reduce the aperture size of a horn antenna. Nevertheless, thanks to the design technique used, the relation between the output aperture and the total horn length for the Ka-band was approximately 0.56 and for the Kuband was something like 0.76. This means that the lengths of the horn antennas are 1.8 and 1.32 times the respective apertures. Furthermore, the taper and the phase center movement inside the respective bandwidths could be controlled and limited to certain limits during the optimization procedure, obtaining a very efficient configuration when they were combined with the reflectors. The horn antennas were based on the combination of horizontal and vertical corrugations and they were designed by the Antenna group of the Public University of Navarra.
Open Access
Asymmetrically and symmetrically coated tapered optical fiber for sensing applications
(SPIE, 2015) Del Villar, Ignacio; Socorro Leránoz, Abián Bentor; Corres Sanz, Jesús María; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
The deposition of a non-metallic thin-film in a symmetrically coated tapered optical fiber leads to the generation of resonances due to guidance of a mode in the thin-film. At certain conditions, the resonances overlap each other, which can be avoided with an asymmetric coated tapered optical fiber, which permits to obtain resonances for TM and TE polarization separately. Numerical results showing the sensitivity to coating thickness and surrounding medium refractive index are also presented for both polarizations.
Open Access
The beauty of anisotropy in extraordinary transmission fishnet metamaterials
(2011) Navarro Cía, Miguel; Beruete Díaz, Miguel; Sorolla Ayza, Mario; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, we explore both numerically and experimentally, the possibility to obtain positive and negative refraction regimes that depend on the wave polarization, exploiting the strong anisotropy of extraordinary transmission fishnet metamaterials.
Open Access
Blind spot mitigation in phased array antenna using metamaterials
(IEEE, 2014) Crépin, Thomas; Martel, Cédric; Gabard, Benjamin; Boust, Fabrice; Martinaud, Jean-Paul; Dousset, Thierry; Rodríguez Ulibarri, Pablo; Beruete Díaz, Miguel; Loecker, Claudius; Bertuch, Thomas; Marcotegui Iturmendi, José Antonio; Maci, Stefano; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this work, a metaradome based on a fakir’s bed of nails is designed and tested in order to suppress the blind directions of a 100-element antenna array. The antenna is a microstrip array designed to operate in X-band. The fakir’s bed metamaterial-like was first approximated using analytical formulas before a full-wave numerical optimization. Experimental results are exposed and confronted to numerical results. They show a significant reduction of the blind spot subsequent to the metaradome addition.
Open Access
Boresight radiation of a dipole antenna with a uniform or non-uniform left handed superstrate
(2006) Sáenz Sáinz, Elena; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Maagt, Peter de; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
In this paper measurements of the radiation performances of a dipole fed by a coaxial balun and a dipole with a left handed superstrate based on a finite periodic repetition of a unit cell are compared. Two types of superstrates, uniform and non-uniform, have been characterised in terms of impedance matching, resonant frequency and gain. First of all the dependence of the impedance matching and resonant frequency with the size of the superstrate has been analysed, having a good impedance matching and a decrease in the resonant frequency as the number of cells increase. By using an anechoic chamber and a receiver horn antenna, the power transmitted at boresight has been measured for different frequencies, observing a filtering behaviour due to the resonant characteristic of the superstrate and an improvement of the power transmitted at the resonant frequency of approximately 3 dB. Comparing the H and E plane radiation patterns of a dipole and the dipole with superstrate, more symmetrical and directive radiation patterns can be observed. Finally, a comparison between the simulated and measured aperture efficiency is presented with a good agreement.
Open Access
Brillouin distributed sensing assisted by Brillouin amplification of pump pulses
(IEEE, 2014) Urricelqui Polvorinos, Javier; Sagüés García, Mikel; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate, for the first time to our knowledge, the extension of the measurement range of Brillouin distributed sensors (BDS) by using a distributed Brillouin amplifier (DBA) to compensate the attenuation of the sensor's pump pulses. The technique is based on injecting an extra DBA pump wave in the fiber to generate an additional Brillouin interaction to that used for sensing. Moreover, the bandwidth of the DBA is tailored to fit that of the pump pulses by deploying a wavelength modulation of the DBA pump that is synchronized to the pump. Experimental proof of concept results demonstrate a fivefold enhancement of the measurement range of a BDS, from 10.36 km to more than 50 km in this particular case. Moreover, it is found that the use of the DBA does not introduce any significant penalty in the detection signal to noise ratio, highlighting the potential of the technique to provide much larger sensing lengths.
Open Access
Brillouin optical time-domain analysis sensor with amplification of pump pulses and tolerant to non-local effects
(SPIE, 2016) Mompó Roselló, Juan José; Urricelqui Polvorinos, Javier; Loayssa Lara, Alayn; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
We demonstrate a simple technique to provide conventional Brillouin optical time-domain analysis sensor with compensation for pump pulse attenuation and tolerance to non-local effects. The technique is based on operating the sensor in loss configuration so that energy is transferred from the probe wave to the pump pulse that becomes amplified as it counter-propagates with the probe wave. Furthermore, the optical frequency of the probe wave is modulated along the fiber so that the pump pulse experiences a flat gain spectrum that equally amplifies all the spectral components of the pulse, hence, preventing distortion. The method is experimentally demonstrated in a 100-km fiber link, obtaining a measurement uncertainty of 1 MHz at the worst-contrast position.
Open Access
Brillouin optical time-domain analyzer for extended sensing range using probe dithering and cyclic coding
(SPIE, 2017) Iribas Pardo, Haritz; Loayssa Lara, Alayn; Sauser, Florian; Llera, Miguel; Le Floch, Sébastien; Ingeniería Eléctrica y Electrónica; Ingeniaritza Elektrikoa eta Elektronikoa
We present an enhanced performance Brillouin optical time-domain analysis sensor that uses dual probes waves with optical frequency modulation and cyclic coding. The frequency modulation serves to increase the probe power that can be injected in the ﬁber before the onset of non-local eﬀects and noise generated by spontaneous Brillouin scattering. This leads to higher detected signal-to-noise ratio (SNR), which is further increased by the coding gain. The enhanced SNR translates to extended range for the sensor, with experiments demonstrating 1-m spatial resolution over a 164 km ﬁber loop with a 3-MHz Brillouin frequency shift measurement precision at the worst contrast position. In addition, we introduce a study of the power limits that can be injected in the ﬁber with cyclic coding before the appearance of distortions in the decoded signal.