Study of mutual coupling and chassis modes coupling through the equivalent circuit model of two monopoles on a small platform

In addition to the mutual coupling between array elements, the coupling to the characteristic current modes of the chassis has to be considered. In this paper, the performance of a two-element monopole antenna on a small rectangular ground plane is analyzed based on a decomposition of the contributions from the elements and the coupled chassis modes. A resonator-based equivalent circuit is proposed to model closely the full-wave simulation which allows the calculation of radiation and impedance contributions from the elements and the chassis modes.