Origami Multimode Ring Antenna Based on Characteristic Mode Analysis

In this paper, a compact ring shaped Multiple-Input-Multiple-Output (MIMO) antenna operating in two high order modes is implemented on an origami waterbomb structure. Operation in two modes allows the single element to act as a MIMO while the foldable waterbomb structure offers frequency and radiation pattern reconfigurability. Characteristic mode analysis is performed to determine the two most desirable modes of operation. The realized gain as well as the reconfigurable nature of the antenna as it is folded is presented.