High-Performance Computational Electromagnetic Methods Applied to the Design of Patch Antenna with EBG Structure

In this contribution High-Performance Computing electromagnetic methods are applied to the design of a patch antenna combined with EBG structure in order to obtain bandwidth enhancement. The electrical characteristics of the embedded structure (patch antenna surrounded by EBG unit cells) are evaluated by means of method of moment technique (MoM) whereas for designing the unit cell, the finite element method (FEM) together with the Bloch-Floquet theory is used. The manufactured prototypes are characterized in terms of return loss and radiation pattern in an anechoic chamber

A thin c-band polarization and incidence angle-insensitive metamaterial perfect absorber

A novel metamaterial absorber design able to operate in the C frequency band is presented, along with an analysis and a method to improve both its bandwidth and its angular stability. Simulation results for a FR4-based design are shown for comparison with existing designs. In addition, a simplified equivalent circuit is provided for a better understanding of the great angular stability and wide bandwidth exhibited by the proposed structure. Moreover, simulations, manufacturing and measurements of a thinner and more flexible metamaterial absorber, keeping the angular stability of the former one, while providing a wide bandwidth, are presente

On the introduction of lumped inductors for optimizing UHF band AMCs in terms of size and angular stability

Loughborough Antennas & Propagation Conference (LAPC, 2017, Loughborough, UK

Angular stability of metasurface perfect absorbers: advances on the design and limitations on measurement

XXXII Simposium Nacional de la Unión Científica Internacional de Radio, Universidad Politécnica de Cartagena, 6 a 8 de septiembre de 2017, Cartagena (España)The aim of this contribution is twofold. On the one hand, some guidelines will be given in order to improve the metasurface absorbers’ (MTAs) angular stability. In order to show that, two angularly stable MTAs are presented taking into consideration the common design specifications (resonance frequency, peak absorption, available dielectric materials and suitable bandwidth) that a designer has to meet. These MTAs are not only angularly stable but also its profile is extremely thin and hence, they can be conformed to whatever objects due to its flexibility. On the other hand, it will be provided a deep insight on the measurement limitations. A quasi-monostatic measurement set-up will be presented to perform measurements under both transverse electric (TE) and transverse magnetic (TM) polarizations varying the angle of incidence. The restrictions in the angular margin that can be measured according to the size of the manufactured finite MTA will be presente

Monostatic and Bistatic Measurements of Metasurfaces on Anechoic Chamber and a Comparison with Electromagnetic Simulations

European Conference on Antennas and Propagation (13th. 2019. Krakow, Poland

Facing the Angular Stabilization of Loop-Based Artificial Magnetic Conductors Through Lumped Inductors

2017 International Conference on Electromagnetics in Advanced Applications (ICEAA), 11 a 15 de septiembre de 2017, Verona (Italia)This work focuses in achieving the angular stabilization of a square loop-based AMC from a novel approach: by exploring the possibilities of introducing lumped inductors. The study is conducted considering the typical constraints an actual designer has to cope with (concerning limited size and dielectric thickness and properties). As a result, a stable AMC in the 5.8GHz band is obtained, meeting the design requirements. Due to its effectiveness, the novel developed methodology can be directly extended to enhance the angular stability of any loop-based AMC, wide spreading their application

Zirconia-Based Ultra-Thin Compact Flexible CPW-Fed Slot Antenna for IoT

An ultra-thin compact flexible CPW-fed slot monopole antenna suitable for the Internet of Things (IoT) applications was achieved as a result of exploring the use of Zirconia-based ENrG’s Thin E-Strate® for the antenna’s design. The electromagnetic characterization of the novel material at the frequency range of interest was analyzed. A comparison was made concerning the required dimensions and the simulation results regarding impedance matching and radiation properties, for three different dielectric substrates: Novel flexible ceramic (ENrG’s Thin E-Strate), rigid Arlon 25N, and flexible Polypropylene (PP). Two different metallization techniques—electrotextile-based and inkjet printing—were used in the fabrication of prototypes based on ENrG’s Thin E-Strate. Return losses measured results for the fabricated prototypes with both procedures was compared, as well as with simulation. The best prototype on the ENrG’s Thin E-Strate was compared with one on Arlon 25N, in terms of radiation properties in an anechoic chamber, and conclusions were drawn

Ultra-Thin Compact Flexible Antenna for IoT Applications

European Conference on Antennas and Propagation, EuCAP 2019 (13th. 2019. Poland

Clinical Predictors of Hyperperfusion Syndrome Following Carotid Stenting: Results From a National Prospective Multicenter Study

[Objectives] The aim of the HISPANIAS (HyperperfusIon Syndrome Post-carotid ANgIoplasty And Stenting) study was to define CHS rates and develop a clinical predictive model for cerebral hyperperfusion syndrome (CHS) after carotid artery stenting (CAS).[Background] CHS is a severe complication following CAS. The presence of clinical manifestations is estimated on the basis of retrospective reviews and is still uncertain.[Methods] The HISPANIAS study was a national prospective multicenter study with 14 recruiting hospitals. CHS was classified as mild (headache only) and moderate-severe (seizure, impaired level of consciousness, or development of focal neurological signs).[Results] A total of 757 CAS procedures were performed. CHS occurred in 22 (2.9%) patients, in which 16 (2.1%) had moderate-severe CHS and 6 (0.8%) had mild CHS (only headache). The rate of hemorrhages was 0.7% and was associated with high mortality (20%). Pre-operative predictors of moderate-severe CHS in multivariate analysis were female sex (odds ratio [OR]: 3.24; 95% confidence interval [CI]: 1.11 to 9.47; p = 0.03), older patients (OR: 1.09; 95% CI: 1.01 to 1.17; p = 0.02), left carotid artery treated (OR: 4.13; 95% CI: 1.11 to 15.40; p = 0.03), and chronic renal failure (OR: 6.29; 95% CI: 1.75 to 22.57; p = 0.005). The area under the curve of this clinical and radiological model was 0.86 (95% CI: 0.81 to 0.92; p = 0.001).[Conclusions] The rate of CHS in the HISPANIAS study was 2.9%, with moderate-severe CHS of 2.1%. CHS was independently associated with female sex, older age, history of chronic kidney disease, and a treated left carotid artery. Although further investigations are needed, the authors propose a model to identify high-risk patients and develop strategies to decrease CHS morbidity and mortality in the future.This study was supported by a Spanish grant from the Instituto de Salud Carlos III (ISCIII-FIS IP14/00971, 2014–2017). The ITRIBIS project has the registration number REGPOT-2013-1. Cooperative Cerebrovascular Disease Research Network (INVICTUS+) (RD16/0019/0015). Dr. Mancha is supported by a Río Hortega contract (CM16/00015). Abbott and Grifols have partial financial supported the conduction of the HISPANIAS project but had no role in the design of the study, interpretation of the data, or manuscript approval.Peer reviewe