This analysis of multisources annular slot antennas includes the study of the influence of the real spatial extension of the excitation sources and of the lumped elements inserted in the slot to conform the radiation pattern or to perform the power matching of the sources. The definition of a reference excitation source insures a field formulation consistent with the electrical circuits definitions taking into account the real spatial extension of the sources. Owing to the introduction of a surface impedance operator in the boundary conditions, the integral formulation also describes the lumped elements whatever the domain of definition of the expansion functions is. The analysis of rotation invariant configurations is also carried out.