A novel design approach for multimode MIMO antenna using modal analysis

In this paper, a novel and systematic approach for design of multimode MIMO (Multiple Input Multiple Output) antenna has been proposed. The antenna consists of a metallic square loop operating with different orthogonal characteristic modes. A modal analysis of this antenna is carried out first by using the concepts of Theory of Characteristic Modes (TCM) to the get physical insights of radiating modes of the antenna. Finally, optimum feeding configurations to excite these modes have been proposed. The concept of reactive loading to control the resonance frequency of a particular mode has been demonstrated. A multimode MIMO antenna is obtained whose performance is similar to the traditional antenna arrays.