@article {09_TAP_Corcoles_FourierSynthesis, title = {Fourier Synthesis of Linear Arrays Based on the Generalized Scattering Matrix and Spherical Modes}, journal = {IEEE Transactions on Antennas and Propagation}, volume = {57}, number = {7}, year = {2009}, month = {July}, pages = {1944-1951}, abstract = {This paper presents a novel, simple pattern synthesis procedure for linear equispaced arrays which can be characterized by a generalized scattering matrix (GSM) and whose radiated field can be expressed as a weighted sum of shifted spherical waves. It can be viewed as an extension of the classic design techniques of the Fourier series (FS) method or the Woodward-Lawson frequency sampling method, to the case in which the individual antenna elements{\textquoteright} patterns and all interelement couplings are taken into account. The design procedure, which yields the excitations needed to achieve the desired pattern, is based on either the FS or the discrete Fourier transform (DFT) of the spherical mode expansion of the array radiated field, as well as on various properties associated to the FS or DFT coefficients. In this work, to compute the GSM of the array and the spherical mode expansion of the field, a validated hybrid full-wave methodology, based on the finite element method and rotation and translation properties of spherical waves, is used. Numerical results of different synthesized array patterns are presented for different arrays made up of dielectric resonator antennas and cavity-backed microstrip circular patches.}, keywords = {Antenna array mutual coupling, cavity-backed microstrip circular patches, dielectric resonator antennas, discrete Fourier transform, discrete Fourier transforms, discrete Fourier transforms (DFT), finite element analysis, finite element method, finite element methods, Fourier series, Fourier synthesis, Frequency, generalized scattering matrix, GSM, interelement couplings, linear antenna arrays, linear arrays, linear equispaced arrays, microstrip antenna arrays, Microstrip antennas, pattern synthesis, S-matrix theory, Sampling methods, Scattering, scattering matrices, shifted spherical waves, signal sampling, spherical mode expansion, spherical modes, Transmission line matrix methods, Woodward-Lawson frequency sampling}, issn = {0018-926X}, doi = {10.1109/TAP.2009.2021929}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=4907114}, author = {J C{\'o}rcoles and Gonz{\'a}lez, M A and Rubio, J} } @article {08_MOPT_CORCOLES_CADstackedpatches, title = {Cad of stacked patch antennas through multipurpose admittance matrices from FEM and neural networks}, journal = {Microwave and Optical Technology Letters}, volume = {50}, number = {9}, year = {2008}, month = {Sep}, pages = {2411-2416}, abstract = {In this work, a novel computer-aided design methodology for probe-fed, cavity-backed, stacked microstrip patch antennas is proposed. The methodology incorporates the rigor of a numerical technique, such as finite element methods, which, in turn, makes use of a newly developed procedure (multipurpose admittance matrices) to carry out a full-wave analysis in a given structure in spite of certain physical shapes and dimensions not yet being established. With the aid of this technique, we form a training set for a neural network, whose output is the desired response of the antenna according to the value of design parameters. Last, taking advantage of this neural network, we perform a global optimization through a genetic algorithm or simulated annealing to obtain a final design. The proposed methodology is validated through a real design whose numerical results are compared with measurements with good agreement.}, keywords = {computer-aided design, finite element methods, neural networks, optimization algorithms, stacked microstrip antennas}, issn = {1098-2760}, doi = {10.1002/mop.23670}, url = {http://onlinelibrary.wiley.com/doi/10.1002/mop.23670/abstract}, author = {J C{\'o}rcoles and Gonz{\'a}lez, M A and Zapata, J} } @conference {05_APS_CorcolesSalazar_SelfAdaptiveFEM, title = {Self-adaptive algorithms based on h-refinement applied to finite element method}, booktitle = {Antennas and Propagation Society International Symposium, 2005 IEEE}, volume = {4B}, year = {2005}, month = {July}, pages = {197-200 vol. 4B}, abstract = {Two error indicators of the solution of an electromagnetic problem by the finite element method (FEM) and two local refinement algorithms for tetrahedral meshes are developed and combined to build up different self-adaptive (h-refinement) algorithms. 2nd order curl-conforming Nedelec tetrahedral elements are used. The performance of the different methods is checked and compared by means of the electromagnetic analysis of resonant cavities.}, keywords = {2nd order curl-conforming Nedelec tetrahedral elements, cavity resonators, computational electromagnetics, Convergence, Eigenvalues and eigenfunctions, Electromagnetic analysis, electromagnetic problem, Erbium, error indicators, finite element analysis, finite element method, finite element methods, h-refinement, Least squares approximation, Maxwell equations, Performance analysis, Resonance, resonant cavities, self-adaptive algorithms, Software performance, tetrahedral meshes}, doi = {10.1109/APS.2005.1552777}, url = {http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=\&arnumber=1552777}, author = {J C{\'o}rcoles-Ortega and Salazar-Palma, M} }