Mutual Coupling Compensation in Arrays Using a Spherical Wave Expansion of the Radiated Field

TitleMutual Coupling Compensation in Arrays Using a Spherical Wave Expansion of the Radiated Field
Publication TypeJournal Article
Year of Publication2009
AuthorsCórcoles, J., M. A. González, and J. Rubio
JournalIEEE Antennas and Wireless Propagation Letters
Keywordsantenna array, Antenna array mutual coupling, Antenna arrays, antenna radiation patterns, dielectric resonator antennas, electromagnetic coupling, field pattern, field radiation, generalized scattering matrix, interelement mutual coupling effect, isotropic-based pattern synthesis method, modular methodology, mutual coupling compensation matrix, Planar arrays, quadratic programming, S-matrix theory, scattering matrices, spherical wave expansion
AbstractThis letter presents a flexible method to compensate the interelement mutual coupling (MC) effects that may degrade the field pattern of an array of real and coupled antennas. A closed-expression for a mutual coupling compensation matrix (MCCM) is derived. The MCCM is used to compensate the presence of the real individual elements' patterns and the interelement MC effects for any excitations obtained with an isotropic-based pattern synthesis method. The MCCM is calculated from the generalized scattering matrix (GSM) of an antenna array and the spherical mode expansion (SME) of its radiated field. For a given array, this MCCM has to be calculated only once since it only depends on the radiating and scattering characteristics of the antenna elements as well as on their location in the array. Conditions regarding null field pattern directions can also be reinforced in the MCCM. To compute the GSM of the array and the SME of the radiated field, a validated full-wave hybrid and modular methodology is used. Numerical results of synthesized patterns where the MC effects have been compensated are presented for arrays made up of dielectric resonator antennas.