Papers by Jose Antonio Marcotegui
Sensors
The practice of sports has been steadily evolving, taking advantage of different technological to... more The practice of sports has been steadily evolving, taking advantage of different technological tools to improve different aspects such as individual/collective training, support in match development or enhancement of audience experience. In this work, an in-house implemented monitoring system for golf training and competition is developed, composed of a set of distributed end devices, gateways and routers, connected to a web-based platform for data analysis, extraction and visualization. Extensive wireless channel analysis has been performed, by means of deterministic 3D radio channel estimations and radio frequency measurements, to provide coverage/capacity estimations for the specific use case of golf courses. The monitoring system has been fully designed considering communication as well as energy constraints, including wireless power transfer (WPT) capabilities in order to provide flexible node deployment. System validation has been performed in a real golf course, validating en...
REE N°5/2015 83 RADARS A ANTENNES ELECTRONIQUES RADAR 2014 Suppression des directions aveugles d’... more REE N°5/2015 83 RADARS A ANTENNES ELECTRONIQUES RADAR 2014 Suppression des directions aveugles d’une antenne reseau grâce aux metamateriaux Par Thomas Crepin1 , Cedric Martel1 , Benjamin Gabard1 , Fabrice Boust1 , Jean-Paul Martinaud2 , Thierry Dousset2 , Pablo Rodriguez-Ulibarri3 , Miguel Beruete3 , Claudius Loecker4 , Thomas Bertuch4 , Jose Antonio Marcotegui5 , Stefano Maci6 Onera, France1 , Thales Systemes Aeroportes, France2 , Universite De Navarre, Pampelune, Espagne3 , Fraunhofer Hfr, Wachtberg, Allemagne4 , Tafco Metawireless, Noain, Espagne5 , Universite De Sienne, Italie6 In this work, a metaradome based on a fakir’s bed of nails has been 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 presented and confronted to nu...
SID Symposium Digest of Technical Papers, 2021
In the last 10 years, the interest of many researchers is directed to the development of methods ... more In the last 10 years, the interest of many researchers is directed to the development of methods for controlling electromagnetic radiation in the subterahertz frequency range of the spectrum (0.1 – 1 THz). This spectral region, corresponding to the domain of millimeter (mm) and submillimeter (submm) waves, has broad prospects for use in high data rate wireless telecommunication systems, security applications, nondestructive testing and quality control of materials, space research, biomedical sensing, etc. [1 2]. To date, a wide class of functional THz photonic devices has been proposed, including filters, phase shifters, absorbers, modulators and switches. Among promising materials suitable for the use in electrically tunable devices in the mm/submm-wave range and competing with semiconductor or graphene structures, liquid crystals (LCs) should be highlighted. In this work, we present the experimental results on the development of a LC-based quasioptical notch filter with electrically controlled rejection frequency operating in the range of 109 120 GHz (wavelength = 2.5 2.75 mm). The filter is designed using the concept of high-impedance surfaces and ultrathin resonant absorbers, which make it possible to fulfill the requirement d/ << 1 for the thickness d of the active LC layer. Its essence lies in creating a narrow-band absorption resonance by integrating a LC layer with a metamaterial structure of a specific design. The spectral narrowness of the resonance allows the operating frequency of the structure to be placed at the front of the frequency response curve, so that even with a relatively small variation of the refractive index this yields relatively large changes in the reflection amplitude when the electric field is applied. For this work, n-quaterphenyl and n-quinquiphenyl have been synthesized. Based on the investigation of the properties of these substances, we selected the most promising ones. The melting point of the synthesized compounds does not exceed 90 – 100 C, and the temperature of the transition to the isotropic state is less than 250 C. Synthesized compounds are characterized by good solubility in most organic solvents and good miscibility with other LC compounds, which makes them promising for practical use as components of LC mixtures with high optical anisotropy. Based on the analysis of the data obtained, the LC composition was prepared. It is characterized by high optical anisotropy (0.39) and low dielectric losses in the gigahertz (microwave) and subterahertz spectral regions (<0.002). Using full-wave electromagnetic simulations in CST Microwave Studio®, we have developed a design of the notch filter wherein a 40-m-thick LC layer was integrated with a metamaterial structure. The latter included 1 passive and 2 active metasurface layers used as electrodes, which were lithographically patterned on top of THz-transparent wafers. The filter had an active zone of 5151 mm filled with meta-pixels, which were implemented to have an independent electrical control in 54 columns to demonstrate a spatially reconfigurable device (Fig. 1).
EPJ Applied Metamaterials, 2016
This paper presents two metamaterial-inspired solutions to mitigate the scan blindness effects in... more This paper presents two metamaterial-inspired solutions to mitigate the scan blindness effects in a phased array antenna. In the first solution, portions of a bed of nails are introduced in the radome to prevent the excitation of surface waves. In the second solution, a superstrate metasurface is designed to synthesize a permittivity tensor optimized to achieve a wide angle impedance matching. In both approaches, the numerical simulations are successfully compared with measurements of a phased array antenna prototype with 100 elements. The wire medium-based solution reveals an effective way for reducing the blind-spot in a wide bandwidth, while the metaradome has been found less suitable for the same purpose.
2012 6th European Conference on Antennas and Propagation (EUCAP), 2012
ABSTRACT Conference code: 90735
Microwave and Optical Technology Letters, 2007
Combining an electromagnetic band-gap structure (EBG) and squared split-ring resonators (SSRRs) i... more Combining an electromagnetic band-gap structure (EBG) and squared split-ring resonators (SSRRs) in a planar microstrip line circuit, negative values of electric permittivity and magnetic permeability can be obtained. This phenomenon arises thanks to the negative permeability of the SSRR particles when they operate in the vicinity of their quasi-static resonance frequency, and the negative permittivity due to the behavior of the EBG structure within the rejected frequency band. Therefore, a novel approach is presented in this article to synthesize a left-handed media in microstrip technology. Full wave simulation results as well as measurement results from a fabricated prototype confirm the left-handed behavior of the interaction.
Microwave and Optical Technology Letters, 2013
In this article, a stripline planar transmission line loaded with complementary split ring resona... more In this article, a stripline planar transmission line loaded with complementary split ring resonators (CSRRs), in order to obtain a frequency selective behavior. Due to the quasi-static resonance frequency of the CSRR elements, given by the excitation by normal incident E-field, a rejected frequency band can be observed. Simulation as well as measurement results reveal the possibility to apply this type of configuration for the implementation of devices in stripline technology.
2014 International Radar Conference, 2014
In this work, a metaradome based on a fakir's bed of nails is designed and tested in order to sup... more 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.
In this work, a negative-ε equivalent response medium is proponed in stripline technology. To ach... more In this work, a negative-ε equivalent response medium is proponed in stripline technology. To achieve band rejection behaviour, Complementary Split Ring Resonators (CSRR) are placed in the central conductor strip of a conventional stripline planar transmission line. Due to strong normal electric field incidence, adequate excitation of the stripline is achieved, leading to band rejection in the quasi-static resonance frequency of the CSRR particles. Full wave simulation results from our own FDTD code and measurement results are presented, showing good agreement.
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Papers by Jose Antonio Marcotegui