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

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

Effect of the ground plane in UHF Chip antenna efficiency

[EN] A study on the effect of the ground plane in a chip antenna efficiency is presented. For the experiment, a chip antenna has been designed to be fabricated in LTCC technology. The size of the ground plane, the clearance area where the antenna is placed and the position of the antenna has been analyzed obtaining their impact in the radiation properties of the antenna. Useful information has been obtained for the design and implementation of small antennas for sub-1GHz application such as ISM bands(868 MHz Eur, and 915 MHz USA) or the new licensed sub-1GHz 5G bands.This work has been supported by the Spanish Ministry of Science, Innovation, and Universities (Ministerio de Ciencia, Innovacion y Universidades) under the FPI research fellowship program (TEC2016-78028-C3-3-P)Molins-Benlliure, J.; Cabedo Fabres, M.; Antonino Daviu, E.; Ferrando Bataller, M. (2020). Effect of the ground plane in UHF Chip antenna efficiency. IEEE. 1-5. https://doi.org/10.23919/EuCAP48036.2020.9136064S1

Eight-Port Wideband MIMO Antenna for Sub-6 GHz 5G Base Stations

[EN] An eight-port wide-band multiple-input multiple-output (MIMO) antenna is presented for base stations applications. The antenna is composed by four unit cells (2×2) separated by a cross-shaped isolating block with a total size of 220×220×28 mm ` (2.42¿×2.42¿×0.3¿ , at central frequency f=fc=3.3 GHz). The unit cell is defined by a square cavity-backed antenna fed with two I-shaped crossed dipoles. The antenna provides 8 independent ports with 21.5 dB of minimum isolation and an impedance bandwidth (S11<¿10dB) of 97% ranging at 1.8-5 GHz. Results show an efficiency higher than 87%, unidirectional radiation patterns and low envelope correlation coefficient. The geometry of the antenna is suitable for scaling this design to a massive MIMO system with the replication of the proposed antenna.This work has been supported by the Spanish Ministry of Science and Innovation (Ministerio de Ciencia e Innovacion) under project PID2019-107885GB-C32.Molins-Benlliure, J.; Cabedo Fabres, M.; Antonino Daviu, E.; Ferrando Bataller, M. (2021). Eight-Port Wideband MIMO Antenna for Sub-6 GHz 5G Base Stations. IEEE. 839-840. https://doi.org/10.1109/APS/URSI47566.2021.970472883984

Sector Unit-Cell Methodology for the Design of Sub-6 GHz 5G MIMO Antennas

[EN] A novel methodology based on the sectorization of multiple-port cavities with azimuthal symmetry into sector unit cells is presented to design 5G multiple-input multiple-output (MIMO) sub-6 GHz antennas. The methodology divides an N-port cavity antenna into N unit cells and predicts the performance of the N-port design with the analysis of two adjacent cells. This approximation reduces the time and complexity of the simulation of cavity antennas with a high number of ports. For the theoretical justification, cavity mode analysis of a closed cavity and characteristic modes analysis of open and sector cavities is addressed. With the use of the proposed methodology, five different cavity designs with circular, square, hexagonal, octagonal, and saw-tooth geometries are presented in this article. In addition, the fabrication of the 4-port circular shape design and its MIMO performance is also studied. Results show an impedance bandwidth of 130% (1.27-6 GHz), and an envelope correlation coefficient (ECC) lower than 0.1.This work was supported by the Spanish Ministry of Science and Innovation (Ministerio Ciencia e Innovacion) under Project PID2019-107885GB-C32.Molins-Benlliure, J.; Cabedo Fabres, M.; Antonino Daviu, E.; Ferrando Bataller, M. (2022). Sector Unit-Cell Methodology for the Design of Sub-6 GHz 5G MIMO Antennas. IEEE Access. 10:100824-100836. https://doi.org/10.1109/ACCESS.2022.32071631008241008361

Optimization of 2D Heterogeneous Lenses via BFGS and Volume Integral Equation Method

[EN] In this paper we apply a quasi-Newton optimization algorithm called BFGS to optimize heterogeneous lenses in 2D by using the volume integral equation method. Different preliminary designs are presented with frequency selective focal point.This work has been supported by the Spanish Ministry of Science and Innovation (Ministerio Ciencia e Innovacion) under project PID2019-107885GB-C32. We would like to thank Prof. Leslie Greengard and for many useful discussions.Vico Bondía, F.; Cabedo Fabres, M.; Ferrando Bataller, M.; Antonino Daviu, E. (2021). Optimization of 2D Heterogeneous Lenses via BFGS and Volume Integral Equation Method. IEEE. 1657-1658. https://doi.org/10.1109/APS/URSI47566.2021.97047751657165

A New Quadrature Method for Singular Integrals of Boundary Integral Equations in Electromagnetism

[EN] In this paper we present a new method to compute singular integrals and nearly singular integrals in the context of boundary integral equations for electromagnetism. In particular the method is well suited for integral equations of the second kind. The method consist of splitting the integral in two parts, one regular, which is computed via adaptive integration, and another singular and local (with very small support of the integrand) which is computed using asymptotic expansion. This method can be applied to any second kind integral equation arising in CEM, like MFIE, Charge-Current integral equation, Non Resonant Charge Current Integral Equation (NRCCIE),...This work was supported by the Generalitat Valenciana under the projects AICO/2019/018.Vico Bondía, F.; Ferrando Bataller, M.; Antonino Daviu, E.; Cabedo Fabres, M. (2020). A New Quadrature Method for Singular Integrals of Boundary Integral Equations in Electromagnetism. IEEE. 1031-1032. https://doi.org/10.1109/IEEECONF35879.2020.9330434S1031103

Designing Slot Antennas in Finite Platforms using Characteristic Modes

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this material for advertising or promotional purposes, creating new collective works for resale or redistribution to servers or lists, or reuse of any copyrighted components of this work in other works.[EN] In this paper, the application of the Theory of Characteristic Modes for the design of narrow-in-width open slot antennas embedded in finite platforms is investigated. Purely magnetic and electric characteristic modes (CM) of a slot etched in both an infinite and a finite ground plane are analyzed, with the aim to provide a physical understanding of the slot behavior and its interaction with the metallic ground plane. Instead of traditional CM analysis, an alternative approach is proposed, which consists in dividing the design procedure into the separate and complementary analysis of purely magnetic and electric CM. Based on this analysis, some guidelines for the design of open slot antennas are provided, and a simple and compact narrow-in-width wideband open slot antenna is designed. Simulations and measurements are presented for the optimized slot antenna, showing an impedance bandwidth of 47.48% with a very stable radiation pattern.This work was supported by the Spanish Ministry of Economy and Competitiveness under Project TEC2016-78028-C3-3.Mohamed Mohamed-Hicho, N.; Antonino Daviu, E.; Cabedo Fabres, M.; Ferrando Bataller, M. (2018). Designing Slot Antennas in Finite Platforms using Characteristic Modes. IEEE Access. 6:41346-41355. https://doi.org/10.1109/ACCESS.2018.2847726S4134641355

Curso de Doctorado con Tecnologías Masivas Online (MOC)

[ES] Se presentan los resultados obtenidos en la puesta en marcha del curso Online de la Escuela de Doctorado de la UPV, denominado "Carrera Investigadora", desde el punto de vista de planificación, desarrollo y resultados.[Otros] The Communication objectives are to present the results of the implementation of the Massive Online Course of the Doctoral School of UPV called "Career Research¿ considerig planning, development and results. It is a course of 2 ECT, taught in the year 2014 with 91 students. The course has been designed using the tools provided by the UPV, especially PoliformaT and Polimedia. It has been an important task of planning and preparation of contents. The course is structured in 7 teaching units, each unit has 5 Polimedia, supplementary material and multiple-choice test. The pace of delivery has been of one unit per week. There have been self-assessments of each unit, a discussion forum, work and final exam. The results of the evaluation and follow-up surveys give good indicators. This is a new experience for an official doctoral level course with online methodologies. The experience could serve as a real case and implement a model for other courses and Masters degree with similar methodologies.Ferrando Bataller, M.; Cabedo Fabres, M.; Antonino Daviu, E. (2014). Curso de Doctorado con Tecnologías Masivas Online (MOC). Editorial Universitat Politècnica de València. 14-25. http://hdl.handle.net/10251/168738S142

Multiport broadband 5G MIMO antenna with very high isolation

[EN] This paper presents a new unidirectional radiating structure with 4 independent radiation patterns, with an isolation of more than 24 dB, and with a bandwidth of 20 %, oriented for use in 5G indoor MIMO base stations. The element can be used as a building block for arrays with a number of antennas of 4x4 or more. The radiating elements are triangular cavities derived from a square cavity with the TMz 11 mode. The 4-port antenna has a very low profile, with a height of 5 mm and the dimensions of the ground plane are less than one wavelength.This work has been supported by the Spanish Ministry of Science and Innovation (Ministerio Ciencia e Innovacion) under project PID2019-107885GB-C32.Llanga-Vargas, A.; Cabedo Fabres, M.; Ferrando Bataller, M.; Peñafiel-Ojeda, CR. (2021). Multiport broadband 5G MIMO antenna with very high isolation. IEEE. 767-768. https://doi.org/10.1109/APS/URSI47566.2021.970461576776