Concentrated Ground Plane Booster Antenna Technology for Multiband Operation in Handset Devices

The current demand in the handset antenna field requires multiband antennas due to the existence of multiple communication standards and the emergence of new ones. At the same time, antennas with reduced dimensions are strongly required in order to be easily integrated. In this sense, the paper proposes a compact radiating system that uses two non-resonant elements to properly excite the ground plane to solve the abovementioned shortcomings by minimizing the required Printed Circuit Board (PCB) area while ensuring a multiband performance. These non-resonant elements are called here ground plane boosters since they excite an efficient mode of the ground plane. The proposed radiating system comprises two ground plane boosters of small dimensions of 5 mm x 5 mm x 5 mm. One is in charge of the low frequency region (0.824-0.960 GHz) and the other is in charge of the high frequency region (1.710-2.170 GHz). With the aim of achieving a compact configuration, the two boosters are placed close to each other in a corner of the ground plane of a handset device (concentrated architecture). Several experiments related to the coupling between boosters have been carried out in two different platforms (barphone and smartphone), and the best position and the required matching network are presented. The novel proposal achieves multiband performance at GSM850/900/1800/1900 and UMTS

A deterministic width function model

Use of a deterministic fractal-multifractal (FM) geometric method to model width functions of natural river networks, as derived distributions of simple multifractal measures via fractal interpolating functions, is reported. It is first demonstrated that the FM procedure may be used to simulate natural width functions, preserving their most relevant features like their overall shape and texture and their observed power-law scaling on their power spectra. It is then shown, via two natural river networks (Racoon and Brushy creeks in the United States), that the FM approach may also be used to closely approximate existing width functions

A deterministic width function model

International audienceUse of a deterministic fractal-multifractal (FM) geometric method to model width functions of natural river networks, as derived distributions of simple multifractal measures via fractal interpolating functions, is reported. It is first demonstrated that the FM procedure may be used to simulate natural width functions, preserving their most relevant features like their overall shape and texture and their observed power-law scaling on their power spectra. It is then shown, via two natural river networks (Racoon and Brushy creeks in the United States), that the FM approach may also be used to closely approximate existing width functions

Modeling geophysical complexity: a case for geometric determinism

International audienceIt has been customary in the last few decades to employ stochastic models to represent complex data sets encountered in geophysics, particularly in hydrology. This article reviews a deterministic geometric procedure to data modeling, one that represents whole data sets as derived distributions of simple multifractal measures via fractal functions. It is shown how such a procedure may lead to faithful holistic representations of existing geophysical data sets that, while complementing existing representations via stochastic methods, may also provide a compact language for geophysical complexity. The implications of these ideas, both scientific and philosophical, are stressed

Hartree-Fock dynamics in highly excited quantum dots

Time-dependent Hartree-Fock theory is used to describe density oscillations of symmetry-unrestricted two-dimensional nanostructures. In the small amplitude limit the results reproduce those obtained within a perturbative approach such as the linearized time-dependent Hartree-Fock one. The nonlinear regime is explored by studying large amplitude oscillations in a non-parabolic potential, which are shown to introduce a strong coupling with internal degrees of freedom. This excitation of internal modes, mainly of monopole and quadrupole character, results in sizeable modifications of the dipole absorption.Comment: 4 pages, 4 embedded figure

Perceived effectiveness (vs Use) of coping (ACSQ) in soccer players

Este estudio analiza la estructura factorial de la versión española (Kim, Duda, Tomás y Balaguer, 2003) del Cuestionario de Aproximación al Afrontamiento en el Deporte (Approach to Coping in Sport Questionnaire, ACSQ-1, Kim, 1999; Kim y Duda, 1997) en 562 futbolistas. Adicionalmente, se plantea la validación de una versión adaptada del ACSQ diseñada para valorar la percepción de efectividad. Los resultados del CFA ponen de manifiesto un ajuste satisfactorio para ambos modelos ACSQ-uso y ACSQ-efectividad, observándose mejores indicadores para el modelo de efectividad (x2/gl=2.57; CFI= .913; TLI= .904; RMSEA= .058). Por otro lado, las relaciones de las diferentes dimensiones de afrontamiento en su versión uso y en su versión efectividad con las variables externas consideradas (ansiedad y autoconfianza) ponen de manifiesto el diferente papel de ambos criterios, y la necesidad, por lo tanto, de contemplar ambos indicadores en la valoración del coping en el ámbito deportivoThis study examines the factorial structure of the Spanish version (Kim, Duda, Tomás y Balaguer, 2003) of the Approach to Coping in Sport Questionnaire (ACSQ-1, Kim, 1999; Kim y Duda, 1997) in 562 soccer players. Additionally, a second aim of this study is to analyze the psychometric properties of an adapted version of ACSQ designed to assess perception of effectiveness. The results of CFA provided a satisfactory fit for both models ACSQ-use and ACSQ-effectiveness, showing better indexes for effectiveness model (x2/df = 2.57; CFI = .913; TLI = .904; RMSEA = .058). Moreover, the relations between ACSQ-use, ACSQ-effectiveness and the external variables (anxiety and self-confidence) show the different roles of both criteria, and the need, therefore, of contemplate both indicators in the assessment of coping in spor

Orbital current mode in elliptical quantum dots

An orbital current mode peculiar to deformed quantum dots is theoretically investigated; first by using a simple model that allows to interpret analytically its main characteristics, and second, by numerically solving the microscopic equations of time evolution after an initial perturbation within the time-dependent local-spin-density approximation. Results for different deformations and sizes are shown.Comment: 4 REVTEX pages, 4 PDF figures, accepted in PRB:R

Editorial: Factors Affecting Host Selection by Mosquitoes: Implications for the Transmission of Vector-Borne Pathogens

Project PGC2018- 095704-B-I00 from the Spanish Ministry of Economy and Competition and from the European Regional Development Fund (FEDER