Equivalent circuit synthesis for a loop antenna based on the singularity expansion method

The singularity expansion method (SEM) is used to derive active equivalent circuits for a plane-wave-excited loop antenna immersed in a lossless and homogeneous medium. The circuits consist of simple modules associated with the dominant pole pairs of the loop, and circuit element values are expressed in terms of the SEM data. Particular attention is paid to the issue of physical realizability. The synthesized circuits have been analyzed under various excitation and loading conditions by a general-purpose circuit analysis code, and the results agree favorably with the responses of the loop computed by other means