Decoupled field integral equations for electromagnetic scattering from homogeneous penetrable obstacles

[EN] We present a new method for the analysis of electromagnetic scattering from homogeneous penetrable bodies. Our approach is based on a reformulation of the governing Maxwell equations in terms of two uncoupled vector Helmholtz systems: one for the electric field and one for the magnetic field. This permits the derivation of resonance-free Fredholm equations of the second kind that are stable at all frequencies, insensitive to the genus of the scatterers, and invertible for all passive materials including those with negative permittivities or permeabilities. We refer to these as decoupled field integral equations.Vico Bondía, F.; Greengard, L.; Ferrando Bataller, M. (2018). Decoupled field integral equations for electromagnetic scattering from homogeneous penetrable obstacles. Communications in Partial Differential Equations. 43(2):159-184. https://doi.org/10.1080/03605302.2018.1446447S15918443

PIFA antenna for smart watch application in the 2.4 GHz band

[EN] 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 work has been supported by the Spanish Ministry of Science and Innovation (Ministerio Ciencia e Innovación) under project PID2019-107885GB-C32.Abdelhakim, A.; Cabedo Fabres, M.; Ferrando Bataller, M. (2021). PIFA antenna for smart watch application in the 2.4 GHz band. IEEE. 703-704. https://doi.org/10.1109/APS/URSI47566.2021.970448070370

Radiation Pattern Reconfigurable Antenna for IoT Devices

[EN] Based on the characteristic mode theory, a versatile radiation pattern reconfigurable antenna is proposed. )e analysis starts from two parallel metallic plates with the same and different dimensions. By means of two PIN diodes, the size of one of the parallel metallic plates can be modified and consequently the behavior of the radiation pattern can be switched between bidirectional and unidirectional radiation patterns. Moreover, a SPDT switch is used to adjust the frequency and match the input impedance. )e reconfigurable antenna prototype has been assembled and tested, and a good agreement between simulated and measured results is obtained at 2.5 GHz band which fits the IoT applications.This study was supported by the Spanish Ministry of Science and Innovation (Ministerio Ciencia e Innovacion) under project no. PID2019-107885GB-C32 and Generalitat Valenciana under project no. AICO/2019/018.Mahlaoui, Z.; Antonino Daviu, E.; Ferrando Bataller, M. (2021). Radiation Pattern Reconfigurable Antenna for IoT Devices. International Journal of Antennas and Propagation (Online). 2021:1-13. https://doi.org/10.1155/2021/5534063S113202

Radiation Pattern Agile Antenna using PIN Diodes and SPDT Switches

[EN] In this paper, a new design of a reconfigurable antenna is proposed. The antenna structure is using two PIN diodes for switching between two radiation patterns (directional and bidirectional) and a SPDT switch to achieve good impedance matching. The simulated results show a good impedance matching, with S11 below -10 dB using the SPDT switch configuration. In addition, the far-field directivity for both configurations is around 5 dB.Zakaria, M.; Antonino Daviu, E.; Ferrando Bataller, M. (2020). Radiation Pattern Agile Antenna using PIN Diodes and SPDT Switches. IEEE. 1771-1772. https://doi.org/10.1109/IEEECONF35879.2020.9329761S1771177

Power Transfer Efficiency Analyzed using Characteristic Mode Coupling Between Two Parallel Loops

[EN] Independently of any electrical contact, running electronic devices such as smartphones, smart watches, RFID tags etc., is now attainable over small and large distances through Wireless Power Transfer technology. Although, designing systems maintaining appreciable power transfer efficiency still not always achievable. Using two parallel loops, the Theory of Characteristic Modes provides physical insight into the power transfer efficiency. Furthermore, to reach straightforward maximization of the modal power transfer efficiency, the focus of this paper is analyzing the impact of the separation distance and the overlapping between the two antennas on the characteristic modes and their contribution in the total efficiency of the power. The study considers different positions and frequencies of the two parallel antennas.This work has been supported by the Spanish Ministry of Science, Innovation and Universities (Ministerio Ciencia, Innovación y Universidades) under the project TEC2016- 78028-C3-3-P.Abderrazak, F.; Antonino Daviu, E.; Ferrando Bataller, M. (2020). Power Transfer Efficiency Analyzed using Characteristic Mode Coupling Between Two Parallel Loops. IEEE. 1-5. https://doi.org/10.23919/EuCAP48036.2020.9135229S1

Design of a PIFA antenna integrated in the watchstrap for smart watch application in the 2.4 GHz Bluetooth band

[EN] 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 work has been supported by the Spanish Ministry of Science and Innovation (Ministerio Ciencia e Innovación) under project PID2019-107885GB-C32.Abdelhakim, A.; Cabedo Fabres, M.; Ferrando Bataller, M. (2021). Design of a PIFA antenna integrated in the watchstrap for smart watch application in the 2.4 GHz Bluetooth band. Íñigo Cuiñas Gómez. 1-3. http://hdl.handle.net/10251/1910631

Redes de datos inalambricos y despliege de una red IEEE 802.11b en la Escuela Técnica Superior de Ingenieros de Telecomunicación de Valencia

Over recent years, the market for wireless communications has enjoyed tremendous growth. Hundreds of millions of people exchange information every day using cellular telephones, and other wireless communication products. The major motivation and benefit from wireless LANs is increased mobility. This article introduces the WLAN technologies, with emphasis on IEEE 802.11.b, that is the most developed one. A review of the existing propagation models suggests a loss propagation model that is compared with the measures, and in this way its good behavior is proved

Utilización de Sistemas Móviles para Aplicaciones de Docencia

[EN] A system developed for the assessment of online tests using mobile devices such as smarphones, tablets and laptops, will be presented in this document. This system is a webapp, developed in PHP, with a mobile interface based in HTML, CSS and JavaScript. The questions can be created using the available tools in platforms like PoliformaT (Sakai), Moodle, Respondus and any other platform adapted to IMS-QTI standard. Using the email and an identification code of each student, will make possible for them to access a test via email, that will be answered in a graphic interface adapted to the device from which the test is being done. The teacher, then, has the possibility to see the answers in real time and visualize statistics. Assessment will be automatized, and the scores can be exported using standard formats ( spreadsheets compatible with Sakai and Padrino) for its specific use within the UPV[ES] En este documento se presentará un sistema desarrollado para la realización y evaluación de encuestas en aulas de forma online, utilizando dispositivos móviles como teléfonos, tabletas y ordenadores portátiles. El sistema consta de una aplicación web, desarrollada en PHP, y un interfaz móvil basado en HTML, CSS y JavaScript. Las preguntas y cuestiones de las encuestas se pueden crear utilizando las herramientas disponibles en plataformas como PoliformaT (Sakai), Moodle, Respondus y otras similares que utilicen el estándar IMS-QTI. A partir de los correos electrónicos de los alumnos y su código de identificación, se podrá acceder a los tests generar exámenes o encuestas, que se envían por correo electrónico, y que se responden con un interfaz gráfico adaptado al dispositivo desde el que se accede. El profesor dispone de las respuestas en tiempo real, y puede presentar las estadísticas de las mismas. Las calificaciones obtenidas se pueden exportar utilizando formatos estándar (hoja de cálculo o ficheros compatibles con Sakai y padrino) para su uso específico en la UPV.Ferrando Bataller, M.; Montero Bayo, L. (2015). Utilización de Sistemas Móviles para Aplicaciones de Docencia. En In-Red 2015 - CONGRESO NACIONAL DE INNOVACIÓN EDUCATIVA Y DE DOCENCIA EN RED. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2015.2015.1525OC

Analysis of Magnetically-Coupled Loops Based On Characteristic Modes

[EN] A preliminary numerical magnetic field study of a wireless power transfer system composed of two interconnected source loops is addressed in this paper. The key feature of this study is to propose a new configuration capable of maintaining a uniform magnetic field density between the two loops. Furthermore, it has been shown that the Theory of Characteristic Modes is a helpful tool for investigating the near field of the magnetically-coupled loops.Abderrazak, F.; Antonino Daviu, E.; Ferrando Bataller, M.; Taldi, L. (2020). Analysis of Magnetically-Coupled Loops Based On Characteristic Modes. IEEE. 121-122. https://doi.org/10.1109/IEEECONF35879.2020.9329736S12112

GRECO: graphical electromagnetic computing for RCS prediction in real time

An innovative approach to computing the high-frequency radar cross sections (RCSs) of complex radar targets in real time, using a 3-D graphics workstation, is presented. The target (typically, an aircraft) is modeled with the I-IDEAS solid-modeling software, using a parametric-surface approach. The high-frequency RCS is obtained through physical optics (PO), the method of equivalent currents (MEC), the physical theory of diffraction (PTD), and the impedance boundary condition (IBC) techniques. The CPU time for the RCS prediction is spent only on the electromagnetic part of the computation, while the more time-consuming geometric-model manipulations are left to the graphics hardware.Peer Reviewe