Programa del congreso

En este artículo se presenta el diseño y realización

de un diplexor en guía de onda y una antena de bocina con lente

de alta ganancia. Ambos componentes han sido especialmente

diseñados para comunicaciones de haz fijo punto a punto 5G en

los rangos de frecuencia de 71/76 GHz y 81/86 GHz (Banda E). El

diplexor está formado por dos filtros paso banda basados en la

combinación de una función de filtrado paso bajo y paso alto.

Además, el diplexor proporciona tolerancias de fabricación muy

relajadas, lo que hace que no necesite ningún tipo de sintonización

reduciendo sus costes de fabricación. En el caso de la antena, para

gozar de alta directividad en dichas frecuencias, se utiliza una

antena de bocina con lente que proporciona más de 38 dBi de

ganancia que cumple las máscaras ETSI. El subsistema propuesto

combina las ventajas de sus altas prestaciones frecuenciales así

como un ensamblaje mecánico sencillo, por lo que resulta

especialmente atractivo para aplicaciones 5G, debido al bajo coste.

Rain attenuation is the major signal impairment for radio links operating at frequencies above 10 GHz and in the EHF (30-300 GHz). The use of such high frequency in terrestrial radio links is one key element in future high data rate front/backhauling services needed in 5G deployments and future wireless generations. Due to the lack of experimental measurements for that frequency band, one approach to determine the link viability is to estimate rain attenuation by using information about the rain drop size distribution (DSD). In this work, specific attenuation for rain is calculated for five frequencies ranging from 40 to 200 GHz, using twelve years of DSD data gathered with a laser disdrometer. Specifically, the extinction cross section, needed for the calculation, is computed for spherical drops by using the Mie theory and using the CST MWS software for non-spherical drops. Once non-spherical drop results are available, polarization analyses are also generated. Results show that at the higher analyzed frequencies, the extinction cross section is moderately higher when the spherical drop model is used. Also, a higher variability of the attenuation for a given rain rate is observed, whereas the differences between the horizontal and vertical polarizations are smaller.

Los modelos de propagación basados en la teoría de trazado de rayos pueden estimar, con cierto detalle, las contribuciones multicamino que alcanzan la antena del receptor, pero tienen dificultades para estimar las contribuciones difusas. En este trabajo se presenta un modelo empírico de scattering difuso que puede incorporarse a los modelos de canal basado en la teoría de trazado de rayos, o simuladores de canal. El modelo de scattering difuso ha sido desarrollado a partir de medidas experimentales del canal radio en el dominio de la frecuencia. Las medidas se realizaron entre 25 y 40 GHz, lo que ha permitido particularizar los resultados en las bandas de 26, 28, 33 y 38 GHz, por ser éstas donde se realizarán los despliegues de 5G en milimétricas. Las medidas se llevaron a cabo en condiciones de propagación con visión directa (LOS, line-of-sight) y obstrucción de la línea de vista (OLOS, obstructed LOS). Los resultados muestran que cuando se introduce el scattering difuso en los modelos de canal es posible predecir con mayor exactitud las métricas que describen el comportamiento dispersivo del canal radio.

In this paper, the design of two telemetry and one GNSS antennas embedded in a single conformal prototype is presented. This multiband low-profile antenna will be integrated in Europa’s first suborbital launcher, MIURA-1. This solution is not only interesting for the launcher’s market, but also, due to the ease of integration in curved surfaces, has potential applications in the space, aviation, or automotive industries.

An improved equiangular spiral antenna with circular polarization is proposed as the radiating element for a phased array antenna intended for new generation space launchers. The spiral antenna has been designed in printed technology in order to achieve a low profile configuration capable to be embedded in the fuselage of the launcher. The bidirectional radiation of the spiral is converted into a unidirectional radiation by introducing the antenna in a metallic cavity. Furthermore, an absorber corona is added inside the cavity. The inclusion of absorbent material inside the cavity is necessary to maintain the radiation characteristics of the antenna without increasing its size as well as to adjust the axial and impedance ratio produced by the cavity. The spiral antenna has been simulated and fabricated in order to experimentally validate its radiating performance. Besides the phased array will operate from 2.0 to 2.3 GHz, wideband results of the spiral antenna has been obtained. The antenna, with a diameter of 0.6λ at 2.0 GHz, provides a 52% relative bandwidth (2.0-3.4 GHz) with a very pure circular polarization.

The mmWave frequencies will be widely used in future vehicular communications. At these frequencies, the radio channel becomes much more vulnerable to slight changes in the environment like motions of the device, reflections or blockage. In high mobility vehicular communications the rapidly changing vehicle environments and the large overheads due to frequent beam training are the critical disadvantages in developing these systems at mmwave frequencies. Hence, smart beam management procedures are desired, to establish and maintain the radio channels. In this paper, we propose that using the positions and respective velocities of the vehicles in the dynamic selection of the beam pair, and then adapting to the changing environments using ML algorithms, can improve both network performance and communication stability in high mobility vehicular communications.

A major roll-out of 5G networks is currently underway around the world. In the first instance, users will connect to the 5G network in a non stand-alone mode. This paper presents a study on the optimization of the event B1 threshold for the inter Radio Access Technologies (inter-RAT) connection between LTE and NR technologies in a E-UTRAN New Radio Dual Connectivity (ENDC) scenario. For this purpose, a system-level simulator has been used to show the impact of changing the threshold value on the global user throughput and retainability using an File Transfer Protocol (FTP) service in a heterogeneous rural setting.

MIMO masivo, del inglés massive MIMO (Multiple-Input Multiple-Output), se contempla como una tecnología habilitante para alcanzar las elevadas tasas propuestas en 5G y 6G en escenarios multiusuario. En este trabajo se analizan las prestaciones de un sistema MIMO masivo a partir de medidas de canal en la banda de milimétricas (mmWave, millimeter wave). Las medidas se han realizado en un escenario de oficina en la banda de 25 a 40 GHz, mediante una sonda de canal implementada en el dominio de la frecuencia, usando un array virtual rectangular uniforme (URA, rectangular uniform array) formado por 144 (12x12) antenas. Las medidas se realizaron en condiciones de propagación con visión directa (LOS, line-of-sight) y obstrucción (OLOS, obstructed LOS). La condición de propagación "favorable" y la máxima capacidad alcanzable se analizan en función del número de antenas de la estación base y del número de usuarios activos. Los resultados se centran en el enlace descendente (downlink) y se particularizan para las bandas de 26, 28 y 38 GHz, por ser éstas las propuestas para los despliegues iniciales de 5G en milimétricas.

New mobile network generation has brought a significant increase in the complexity of the management tasks due to the variety and heterogeneity of services and scenarios. In this new context, network optimization in terms of capacity and coverage becomes essential for operators. This work presents a detailed analysis of the impact of adjusting azimuth and horizontal antenna beamwidth in relation to capacity and coverage in a multiconnectivity scenario. Results show that the modification of these antenna parameters has different effects depending on the network conditions.

En este trabajo se presenta un análisis del canal MIMO masivo en una picocelda de interior con un elevado número de terminales de usuario activos. El análisis se basa en los resultados de una campaña de medidas realizada en la banda de 3,2 a 4 GHz en un escenario de tamaño reducido, en el que los usuarios (hasta un máximo de 20) se colocan de forma ordenada. Para evaluar las prestaciones del canal MIMO masivo resultante, se incluyen resultados de la capacidad suma y de la eficiencia espectral. Además, y en lo que respecta a la eficiencia espectral del canal, se presenta y discute un análisis que muestra la dispersión y las diferencias entre la contribución individual de cada usuario activo.

This paper presents an affordable free space material characterization for W-band. The system has been developed by Anteral Company and consists on a pair of W band focusing lens horn antennas. This system focuses the electromagnetic radiation at 6 cm from the lens surface in an area of less than 7 mm diameter where the material must be positioned. A software tool has been developed to extract easily the relative permittivity and the delta tangent of the material. This paper presents the system, the W-band focusing lens horn antennas characterization and some obtained results.

The need for technological development in the agri-food industry to achieve more sustainable and productive agriculture has become more urgent. Nowadays the possibility to measure online parameters in production lines in agri-food industries would increase the quality of production, reduce costs, optimize the shelf life of products and reduce food waste and food loss. In the tomato industry, the online measurement of ⁰Brix parameter, could be a great advance in the production quality control optimization. This work aims to investigate the potential of Terahertz spectroscopy to determinate ⁰Brix parameter based on PLSR (Partial Least Square Regression) methods.

In this contribution to the conference, we present different methods to improve the dynamic range of mobile radio channel measurements using a channel sounder in the frequency domain for millimeter wave (mmWave) propagation measurements. The advantages of using a radio over fiber (RoF) link are explained to avoid the losses introduced by a coaxial cable in measurements carried out in indoor and outdoor environments. Furthermore, measurements are carried out in a laboratory environment in order to obtain the optimal configuration parameters to carry out large measurement campaigns in the shortest possible time while maintaining the highest possible dynamic range and the correct calculation of the dispersion parameters. Finally, a simple protocol is disclosed to obtain the optimal parameters mentioned through three short steps.

This paper presents an architecture based on wireless ad hoc networks for the structural health monitoring of buildings. The solution consists of a set of ten sensor nodes (accelerograph stations) as well as a main node or gateway. The communication among the devices were configured through a multi hop topology. Furthermore, the gateway node incorporates an automatic event detection system where the sensors nodes upload the information of the seismic events to the cloud (Google Drive). This proposal contributes in the design and implementation of resilient communications systems on real scenarios. Regarding the network performance, several experiments were carried out in order to evaluate the throughput, RTT and the time to transmit the data of events. Finally, results of a seismic events detected is presented which evidence the proper operation of the architecture proposed

An upgraded version of the complementary strip-slot radiating element is reviewed. The original radiating element consists in a microstrip-fed slot in transmission cofiguration. In the proposed modification, the slot is backed by a cavity in order to obtain unidirectional radiation. The presence of this cavity changes the behavior of the slot. A new equivalent circuit is used to propose a design methodology for broadband operation. Two array designs are simulated and implemented: a phased array and a log-periodic array. Promising experimental results verify the unidirectional radiation and the wide bandwidth of these antennas.

The authors propose a circuit methodology for the design of broadband stacked microstrip antennas fed through an aperture. An equivalent circuit (EC) is introduced for the antenna, which consists of an LC series resonator (the feed) plus two capatively coupled LC parallel resonators (the stacked patches). The circuit parameters are determined in terms of antenna simulations by means of a numerical de-embedding procedure. Then, the stage of the EC representing the two patches is designed using a circuit topology that implements a non-standard quasi-Chebyshev second order bandpass filter response. This non-standard topology enables a design of stacked microstrip antennas with bandwidths in excess of 30% by simply stacking one rectangular patch above another rectangular patch with inner and meandering slots. A prototype of the antenna has been fabricated and measured. Good agreement has been found between simulation and measurements for the return losses and the radiation patterns.

En este trabajo se estudiará el diseño de una agrupación de ranuras en banda K con una alimentación por onda progresiva proporcionada por la tecnología de guía de onda integrada en sustrato, más conocida como Substrate Integrated Waveguide (SIW). Las antenas con alimentación tipo serie o por onda progresiva proporcionan grandes ventajas tales como una gran compacidad estructural (en comparación con las redes de alimentación corporativas), banda ancha o altas prestaciones en cuanto a ganancia y eficiencia. Además, según aumenta la frecuencia este tipo de antenas son capaces de implementar un desapuntamiento del haz principal de radiación que puede ser interesante en diversas aplicaciones.

Sin embargo, normalmente las antenas de onda progresiva presentan cambios rápidos de su capacidad de acoplo con la frecuencia. Esto se traduce en que, si las especificaciones de eficiencia o de estabilidad del diagrama de radiación en banda de nuestro diseño son muy exigentes, puedan no cumplirse. Dicho de otro modo, el comportamiento típico en banda de las antenas de este tipo puede reducir el ancho de banda efectivo de la antena. Por tanto, en este trabajo se ha diseñado una antena de tipo array plana que proporcione alta ganancia, así como un incremento del ancho de banda efectivo de la antena en términos de radiación y eficiencia.

In this paper, a compact dual-feed annular ring patch antenna that covers two 5G millimeter-wave bands is presented. The bandwidths covered are the n258 (24.25 - 27.5) GHz and the n260 (37 - 40) GHz with polarization diversity due to the inclusion of a dual-feed aperture-coupled system.

This paper presents a Planar Inverted-F Antenna (PIFA) design for a smartwatch application, optimized to operate on the 2.4 GHz Bluetooth frequency band, on the proximity of the human forearm. The PIFA antenna is mounted on the watchstrap that is used as the antenna substrate. The antenna is fed in a singular way, since a coplanar wave-guide (CPW) transmission line is used to excite the antenna. The antenna is integrated in the watchstrap, curved over the phantom forearm and simulated along with the watchcase. A return loss of –20 dB is obtained at 2.4 GHz, and an efficiency of -5 dB, which represents a good efficiency taking into account the effect of the human forearm.

This contribution contains the general lines of the project Erasmus+ UNIFORS 2020, focused on soft skills at university curricula. A wide survey on demanded and needed soft skills in companies is the support to define a program for a course for training soft skills among university students. The selection of soft skills for such a course, as well as the definition and the experience in delivering it, are the contents of the work.

El proyecto de Talentos inclusivos es una innovadora experiencia llevada acabo desde la Universidade da Coruña en colaboración con ASPACE Coruña (Asociación de padres de personas con parálisis cerebral) y la Consellería de Educación de la Xunta de Galicia.

En este proyecto desde ASPACE, las personas con parálisis cerebral presentan una serie de dificultades con las que se encuentran en el día a día. Los profesores universitarios del CITIC definen unos retos tecnológicos para resolver esas dificultades y se organizan grupos de trabajos colaborativos formados por alumnos de instituto (cuarto de la ESO y primero de bachillerato) y personas con parálisis cerebral para desarrollar una solución tecnológica que solucione el reto definido. Los profesores de instituto y de universidad tutorizan el trabajo del grupo. En este curso 2020/2021, se han definido 45 retos, han participado 8 institutos y están desarrollando soluciones para resolver 10 de esos retos.

Con este proyecto se busca por un lado visibilizar los problemas con los que se enfrenta en su vida diaria la persona con discapacidad y por otro lado que los chicos de instituto experimenten como la tecnología aplicada puede ayudar a mejorar la calidad de vida de las personas.

The results obtained in University degrees are evaluated annually by means of different statistical indicators. There are several factors that can disrupt these indicators, so it is important to conduct detailed studies that go beyond the calculation of a result based on academic grades. In this paper, we will conduct a multilevel study to determine the impact of the online model used during the 2019-2020 academic year under the effects of COVID-19. We will start by comparing the trend of some of those indicators for the Degree in Computer Engineering of the three universities of the Galician university system. Subsequently, we will further study these indicators by course level and quarter in the case of one of the degrees, and we will finish by focusing on the analysis of several subjects of this degree.

The educational software tool Dosher is presented for the analysis of super heterodyne demodulation of signals, being applicable for enhancing the understanding and learning of the principles of communication theory mainly in Telecommunication engineering. This tool is intended to assist students (high school, undergraduate as well as Ph.D.) about the knowledge of the so-called super heterodyne receivers. Thanks to Dosher (DOwn Super HEterodyne Receiver), students will be able to check how the demodulation process from radiofrequency band down to base band takes place in the frequency domain. Furthermore, they will be able to fully design the receiver, analyze the unwanted effect called Image Frequency, or create reports compiling the expected results and design obtained. To the best of the authors’ knowledge, neither professional nor educational software alternatives for the learning of this field of communication theory have been proposed so far. Dosher is a user-friendly teaching-oriented software developed with MATLAB that successfully combines the use of signal graphical representation with accurate results at any stage of the receiver.

Both conventional Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) and Discrete Fourier Transform Spread OFDM (DFT-S-OFDM) have been adopted for their use in the Physical Uplink Shared Channel (PUSCH) in the 5G New Radio (NR) standard. While CP-OFDM can better exploit the frequency characteristics of the channel, DFT-S-OFDM has the advantage of a lower peak-to-average power ratio (PAPR). Due to the interactions between PAPR and power amplifier (PA) non-linearity, users using DFT-S-OFDM waveform may benefit from a potentially higher PA efficiency and extend their coverage by increasing their transmit power. In this paper we study the uplink performance of both waveforms and their interaction with non-linear PA and uplink power control in the millimeter-wave (mmWave) band to determine their optimal operational range.

In the 3GPP LTE Release 13, NB-IoT was standardized to provide wide-area connectivity for IoT. To optimize network signalling and power consumption, control plane (CP) and user plane (UP) optimizations were introduced. Also, to support infrequent small data transmissions, in Release 15 Early Data Transmissions (EDT) was introduced, where the data is multiplexed with NAS signalling. Therefore, this paper analyses the latency performance of the different NB-IoT optimizations. The study, which has been carried out in a simulated cellular factory environment, has been performed for different packet sizes. Evaluation results show that with low packet size, EDT with CP provides lower latency. However, with higher packet sizes, user plane solutions provide better latency.

Mobile networks have gained importance in recent years thanks to the massive use of the Internet in the mobile terminal. It is very useful to know the impact on the network when any type of event occurs in the city to avoid failures in its operation due to the high attendance of the areas where the event occurs. That is why, in this work the impact of different mobility models on the cellular network is studied, as well as determining which of these models are the most optimal and realistic in relation to the study of a real scenario. Consequently, mobility models are developed on a simulation environment where users move through the areas near the event. For its evaluation, comparative results are obtained respect to the behavior of the number of users per cell for each mobility model, SINR variation and the trade-off between computational cost and mobility model complexity.

High-precision indoor location has become a necessity for the new location-based services that are emerging around 5G. The European LOCUS project is a research project that seeks to achieve high-precision location based on the 5G network. This work reflects one of the proof-of-concepts of theLOCUS project in which we propose the opportunistic fusion ofdifferent technologies, such as Ultra Wide Band (UWB) and WiFi Fine Time Measurement (FTM), to improve location accuracy.For this purpose, an experimental setup has been settle to validate the presented system, using both technologies due to their incorporation in the latest smartphones on the market. In this way, the use of fusion in trilateration is validated as an algorithm that significantly improves the positioning error by overdetermining the localization problem and also improves the coverage area.

La creciente complejidad de las redes móviles, aun más con el desarrollo del 5G, dificulta la relación de las tradicionales métricas radio de capas bajas utilizadas hasta ahora, con la calidad real del usuario. Estas medidas conocidas como KPI (Key Performance Indicator) son fáciles de obtener en comparación con los KQI (Key Quality Indicator), pero son estos últimos, los que dan una aproximación real a la calidad del usuario. El problema de los KQI es la dificultad de obtención, consumen tiempo y batería en los dispositivos móviles, ya que la amplia mayoría de ellos requieren de la descarga y subida de archivos, peticiones http, transmisión en directo de video, entre otros. Se propone y evalúa en una red celular real, un marco completo para estimar KQI utilizando KPI e información adicional, consiguiendo las ventajas de precisión de los KQI a partir de la facilidad de obtención de los KPI.

Magnetic coupling between components may greatly reduce performance of compact electromagnetic interference filters at frequencies above several hundreds of kilohertzs or a few megahertzs. This work analyzes the performance of shielding strategies based upon the use of copper bands (high-conductivity material) and/or flexible ferrite sheets (high-permeability material) to improve the attenuation provided by these filters.

We make use of a high-frequency circuit model of the filter and an advanced search algorithm to identify the condition of partial shielding as the main cause of the limited shielding performance of high-conductivity materials and to quantify the reductions in the mutual inductances between the components of the filter that can be obtained by using alternative arrangements of the shielding structures that include ferrite sheets. Measurements on several filter prototypes demonstrate that the shielding techniques proposed here can provide 20 to 30dBs increase in the attenuation provided at high frequencies by the electromagnetic interference filter for differential mode noise.

Testing the immunity to conducted radiofrequency disturbances, induced by radio-frequency fields, is fundamental within the electromagnetic compatibility assessment of devices having input and/or output cables. This procedure requires assuring the repeatability and accuracy of the test level applied, that is, the voltage and power of the signal injected into the equipment’s cables when these tests are performed. During a preliminary calibration, different instruments could be employed to measure and adjust the disturbance voltage to the corresponding test level, typically, power meters, test receivers or spectrum analyzers. In this paper it is proposed to use oscilloscopes as measuring device and the calibration method has been adapted accordingly. Results indicate oscilloscopes enable valid and time efficient measurements of the radiofrequency voltage signals involved in the tests according the EN 61000-4-6 standard method, with comparable accuracy at lower costs, while it provides further measurements analysis capability and increased robustness.

La tendencia actual a desarrollar dispositivos electrónicos cada vez más pequeños, con mayores funcionalidades y mejor rendimiento provoca que las interferencias electromagnéticas (EMI) se conviertan en un gran problema. El apantallamiento contra las EMI es un aspecto importante que hay que tener en cuenta en el proceso de diseño de un dispositivo electrónico. Cuando el problema se detecta en etapas posteriores una de las técnicas más empleadas se basa en recurrir al uso de board-level shields (BLS). En este artículo se describe un método de medida empleado para la caracterización de una shielding cabinet sin juntas basado en la medida de las pérdidas por inserción (insertion loss). Además, se incluyen las simulaciones realizadas para comprobar cómo afecta el efecto de las aberturas en la efectividad del apantallamiento de la cabinet.

Serrated reflector systems are widely used in com-pact range antenna measurement (CATR) setups. Besides max-imizing the size of the reflector, serrations are essential forimproving the size and quality of quiet zones. Multiple serrationgeometries are available in the literature but, for the most part,there seems to be no evident relationship between the char-acteristic parameters of these geometries and their implicationin quiet zones’ size and quality. Optimization algorithms andcomparison metrics are needed in order to reach an optimumedge serrations geometry. This work presents a method tooptimize an offset reflector system that can be generalized toany CATR reflector setup.

In this paper we present a broadband circularly polarized low profile metasurface (MTS) antenna. A metasurface of 3x4 rectangular cells is first analyzed using characteristic mode analysis (CMA). As a result, two modes with orthogonal current distribution and almost 90º phase difference are selected to contribute to the circular polarization radiation.

Finally, an appropriate rotated coplanar waveguide (CPW) feeding line is chosen to excite the two modes. The simulation results show 3-dB axial ratio band of 13.8% (5.6-6.43GHz), an impedance bandwidth of 24.1%, and a peak gain of 8dBi. The dimensions of the proposed design are 1.0λ0×1.0λ0×0.059λ0.

RF energy harvesting through the use of rectennas, an element with which DC power is obtained from electromagnetic waves found in free space, is currently gaining momentum as new designs are being proposed. The state of the art of harvesting is mostly focused on the design of single-band rectennas. However in this paper, a multi-tone system has been designed where several frequency bands will be collected. The design of the proposed rectenna is based on both short-circuited patch antenna and Crofton-Walton rectifier. The simulation results are shown, obtaining really good efficiency and reflection coefficient values. The main conclusion reached in this work is that a multi-tone system is more challenging than a single-frequency system with advantages such as higher DC output voltage, efficiency and diversity.

Este artículo propone una antena de cuatro puertos con respaldo de cavidad de banda ancha para aplicaciones de estaciones base interiores. La antena está compuesta por una cavidad abierta de forma cuadrada con un bloque aislante en forma de X situado en el centro y 4 monopolos dispuestos de forma simétrica en la apertura de la cavidad. Para su diseño se ha utilizado una metodología basada en el análisis de modos característicos (CMA) para identificar los modos que contribuyen al acoplamiento y justificar el uso del bloque en forma de X para incrementar el aislamiento entre puertos. La antena dispone de cuatro diagramas de radiación unidireccionales y un ancho de banda (S₁₁<-10 dB) que opera desde 1.55 GHz hasta 6 GHz (118%), cubriendo la mayoría de las bandas 5G sub-6 GHz. El aislamiento entre puertos es de mínimo 16 dB y la eficiencia superior al 84%. La antena es de fácil fabricación y presenta un tamaño compacto de 129.5 x 129.5 x 28.2 mm³ (0.68λ x 0.68λ x 0.15λ, a la frecuencia mínima f=f_min=1.55 GHz).

A circularly polarized implantable antenna (CPIA)

working at industrial, scientific, and medical (ISM) band (915)

MHz is presented in this communication. The proposed CPIA

consists of a meandered line surrounded by a U-structure

to guarantee circular polarization. With this combination, we

achieve a wideband axial ratio (AR) of 27 % from 770 to

1010 MHz, and a wideband reflection coefficient of 20 % from

809.4 to 989.8 MHz. Moreover, 12 m distance communication

is guaranteed for a link margin of about 30 dB. The antenna

has a compact size of 0.01 × 0.01 λ<sup>2, which makes it a good

candidate for implantable devices.