Printed antennas studies based on equivalent magnetic current characteristic modes

In the past 10 years due to their attractive features, the characteristic modes have been applied widely for the wideband and Multiple Input Multiple Output (MIMO) antennas design. In these works the radiator was a metallic structure located in air. Fabres in [M. C. Fabres, “Systematic Design of antennas using the theory of characteristic modes.” Universidad Politecnica de Valencia, Valencia, Ph.D. dissertation, pp 118–120, February 2007] applied the classical theory of characteristic modes to study parallel plates separated by air. However, utilizing the typical characteristic modes analysis the resulting electric eigencurrents do not give clear information about the structure radiation.