Multibeam synthesis with minimum SLL through linear programming from the GSM-analysis of an array

TitleMultibeam synthesis with minimum SLL through linear programming from the GSM-analysis of an array
Publication TypeConference Paper
Year of Publication2009
AuthorsCórcoles, J., and M. A. González
Conference NameAntennas and Propagation Society International Symposium, 2009. APSURSI '09. IEEE
Date PublishedJune
KeywordsAntenna arrays, array pattern synthesis, complex radiating structures, computational electromagnetics, Design optimization, dielectric resonator antennas, electromagentic analysis, Electromagnetic analysis, electromagnetic fields, Electromagnetic radiation, electromagnetic waves, generalized scattering matrix, GSM, linear antenna arrays, linear programming, minimum maximum sidelobe level, multibeam antennas, multibeam synthesis, optimization, S-matrix theory, SME, spherical mode expansion
AbstractThe application of all sort of optimization techniques to different array pattern synthesis problems has been widely studied since the early days of antenna array design. Most of these works (generally having constraints on the array configuration) take for granted several assumptions, among which one can highlight considering isotropic sources and not taking into account coupling between array elements. Great advances have been achieved in the field of computational electromagnetics which allow complex radiating structures, including finite antenna arrays, to be analyzed from a full-wave approach inherently taking into account all electromagnetic effects. Recently, new techniques for the afore-mentioned pattern synthesis problems with the inclusion of this rigourous electromagentic (EM) analysis have been developed. In this work, the authors propose an EM-based design technique which yields the excitations of an arbitraty planar array to output a field pattern with minimum maximum sidelobe level (SLL) given the directions of various main beams with specified mainlobe widths and different relative amplitudes and phase differences. The array is characterized through a generalized scattering matrix (GSM) and its radiated field is expressed as a spherical mode expansion (SME). The accurate determination of the array GSM is needed to have it rigourously characterized, so the use of a full-wave technique is required in case complex antenna elements or arbitrary array configurations are considered. We develop the formulation to arrive at a standard linear programming (LP) problem. Numerical results of a linear array of dielectric resonator antennas (DRA's) are presented.