Modeling and estimation of mutual coupling in a uniform linear array of dipoles

The mutual coupling in a uniform linear array (ULA) of dipoles is calculated using basic electromagnetic concepts. Since the coupling often is unknown and needs to be estimated, a simpler model is proposed based on the electromagnetic analysis. The parameterization of this model is shown to be locally unambiguous. A necessary condition for the joint solution of directions and coupling parameters to be unique is also derived. Finally, the directions and coupling parameters are estimated using a maximum likelihood method. It is found that the simpler coupling model with just a few parameters well describes the full electromagnetic model.