Browsing by Author "Brégains, Julio"
Now showing items 1-20 of 34
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A Comparison of Optimization Techniques for Power Patterns with Low Sidelobes Generated by Linear Arrays with Efficient Excitation Distributions
Smith, S. Kyle; Brégains, Julio; Kathleen, L. Melde; Ares Pena, F. J. (John Wiley & Sons, Inc., 2005-04-05)[Abstract] Equispaced linear arrays that have uniformly excited central elements and monotonically decreasing flanking segments have been shown to yield low-sidelobe patterns with specified constraints on the effective ... -
A MATLAB Interface for Analyzing Conformal Arrays Composed of Polarized Heterogeneous Elements
Brégains, Julio; García-Naya, José A.; González-López, Miguel; Castedo, Luis (Institute of Electrical and Electronics Engineers, 2011-10)[Abstract] As an extension and improvement of a previous work, this paper presents a graphical interface designed with MATLAB®, which is capable of representing both the spatial and electrical configurations of a conformal ... -
A MATLAB Tool for Visualizing the 3D Polar Power Patterns and Excitations of Conformal Arrays
Brégains, Julio; García-Naya, José A.; González-López, Miguel; Dapena, Adriana (Institute of Electrical and Electronics Engineers, 2010-08)[Abstract] This paper describes the implementation of a MATLAB® tool to plot the three-dimensional polar radiation diagram generated by a conformal antenna array. A related tool has also been developed for visualizing the ... -
A WiMAX Conformal Broad-Beam Antenna
Brégains, Julio; Castedo, Luis; Ares Pena, F. J. (Institute of Electrical and Electronics Engineers, 2010-12)[Abstract] The numerical model of a very simple conformal antenna, prepared to work in the 3.4 to 3.6 GHz WiMAX range, is presented. The pattern radiated by the proposed antenna displays high gain and excellent linear ... -
An Experimental Set-Up for Measurement of the Power Absorbed from 900 MHz GSM Standing Waves by Small Animals, Illustrated by Application to Picrotoxin-Treated Rats
López Martín, E.; Brégains, Julio; Jorge Barreiro, F. Javier; Sebastián Franco, José Luis; Moreno Piquero, E.; Ares Pena, F. J. (Electromagnetics Academy, 2008)[Abstract] We describe an experimental set-up for exposure of small animals to radiofrequency standing waves that allows direct measurement of the power absorbed by the animal. Essentially, the set-up consists of a metallic ... -
Analysis, Synthesis, and Diagnostics of Antenna Arrays through Complex-Valued Neural Networks
Brégains, Julio; Ares Pena, F. J. (John Wiley & Sons, Inc., 2006-08)[Abstract] It is shown in this paper that when artificial neural networks are extended to be complex valued, they can be incorporated as a very powerful and effective tool in the analysis, synthesis, and diagnostics of ... -
Application of Time Modulation in the Synthesis of Sum and Difference Patterns by Using Linear Arrays
Fondevila, J.; Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (John Wiley & Sons, Inc., 2006-05)[Abstract] In this paper, time modulation is applied to a small number of elements of a linear array that radiates either sum or difference patterns, in order to take control over their sidelobe levels. The simulated ... -
Avoiding Interference in Planar Arrays through the Use of Artificial Neural Networks
Brégains, Julio; Dorado, Julián; Gestal, M.; Rodríguez, J. A.; Ares, F.; Pazos, A. (Institute of Electrical and Electronics Engineers, 2002-08)[Abstract] This article implements an artificial neural network to find, through computer simulation, the excitations of a square planar array. The array is composed of 52 uniformly spaced subarrays, and has a quasi- in ... -
Beam Reconfiguration of Linear Arrays Using Parasitic Elements
Rodríguez, J. A.; Trastoy, A.; Brégains, Julio; Ares Pena, F. J.; Franceschetti, G. (The Institution of Engineering and Technology, 2006-02-13)[Abstrac] An innovative method for linear arrays beam reconfiguration is presented. This pattern reconfigurability is achieved by a mechanical displacement of a parasitic array located in front of an active one. Two worked ... -
Calculating Directivities with the Two-Dimensional Simpson's Rule
Brégains, Julio; Coleman, I. C.; Ares Pena, F. J.; Moreno Piquero, E. (Institute of Electrical and Electronics Engineers, 2004-08)[Abstract] C++ routines implementing the simple generalization of Simpson's rule to two dimensions for calculating antenna directivities compare well with methods currently available in common symbolic and numerical ... -
Circularly Polarized Arrays of Sequentially Crossed Dipoles
Brégains, Julio (Genxcellence Software Pvt. Ltd., 2013-11)[Abstract] Usual configurations of dipoles that radiate circularly polarized fields consist of elements arranged in crossed pairs, with one component of each pair in top of the other component. As an alternative to this, ... -
Design of Reconfigurable Array Antennas With Minimum Variation of Active Impedances
Mahanti, G. K.; Das, S.; Chakrabarty, A.; Brégains, Julio; Ares Pena, F. J. (Institute of Electrical and Electronics Engineers, 2006-12)[Abstract] In this letter, the authors propose an optimization method based on the genetic algorithm (GA) to reconfigure a linear array of vertical half-wavelength dipole antennas to generate two patterns with minimum ... -
Dual-Beam Steerable TMAs Combining AM and PM Switched Time-Modulation
Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (MDPI, 2022)[Abstract] Wireless sensor networks (WSN) are increasingly requiring directional antennas that not only provide higher capacity, security, transmission range or robustness against interference, but also contribute with ... -
Effects of Measurement Distance on Measurements of Symmetrically Shaped Patterns Generated by Line Sources
Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (Institute of Electrical and Electronics Engineers, 2003-02)[Abstract] Symmetrically shaped patterns, generated by real continuous linear apertures derived from Taylor distributions, resemble Taylor sum patterns in regard to the distance-dependence of their sidelobe heights. Their ... -
Impact of Time-Modulated Arrays on the BER of Linear Digital Modulations
Maneiro-Catoira, Roberto; Brégains, Julio; García-Naya, José A.; Castedo, Luis (Taylor & Francis, 2015-08-21)[Abstract] Time modulation provides a simple way to control the power radiation pattern of an antenna array. By appropriately selecting the parameters of a Time-Modulated Array (TMA) it is possible to obtain a reconfigurable ... -
Matrix Pseudo-Inversion Technique for Diagnostics of Planar Arrays
Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (The Institution of Engineering and Technology, 2005-01-06)[Abstract] It is shown, by means of numerical simulation, that the Moore-Penrose pseudoinverse of a matrix taken from an overdetermined system can be applied to retrieve the excitation distribution of a planar array of ... -
Measurement Effects on Ø-Symmetric Shaped Patterns Generated by Circular Continuous Apertures
Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (Institute of Electrical and Electronics Engineers, 2003-10)[Abstract] Sidelobe-level and ripple behaviors of Ø-symmetric shaped patterns, generated by circular, real and complex, continuous Taylor distributions, is analyzed as a function of measurement distances. This paper reveals ... -
Near Field Quasi-Null Control with Far Field Sidelobe Level Maintenance in Line Source Difference Patterns
Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (Taylor & Francis, 2003)[Abstract] A previously developed method to place a quasi-null in a specified angular position of the near-field line source in sum patterns while, simultaneously, the far-field sidelobe level is maintained under a desired ... -
Near-Field Quasi-Null Control with Far-Field Sidelobe Level Maintenance in Line Source Distributions
Brégains, Julio; Ares Pena, F. J.; Moreno Piquero, E. (The Institution of Engineering and Technology, 2002-06-06)[Abstract] An improving method, based on the Taylor line source, that allocates a quasi-null in a specified angular position of near-field pattern, and simultaneously controls the general topography of the far-field sidelobe ... -
New Toroidal Beam Antennas for WLAN Communications
Brégains, Julio; Franceschetti, G.; Roederer, A. G.; Ares Pena, F. J. (Institute of Electrical and Electronics Engineers, 2007-02)[Abstract] The design of a number of new antennas that radiate linearly polarized toroidal beams is described. The developed procedures are based on the use of a method of moments commercial software tool. Several numerical ...
