Multi-Mode Antenna Concept based on Symmetry Analysis of Characteristic Modes

A multi-mode antenna concept based on a symmetry analysis of characteristic modes is presented for use in massive MIMO antenna arrays. A hexagonal plate is chosen as the basis of the antenna concept due to its interesting geometric properties. In particular, a symmetry analysis using group theory and representation theory is conducted in conjunction with a characteristic mode analysis, yielding that a hexagonal plate offers eight mutually orthogonal sets of characteristic surface current densities. On this basis, eight uncorrelated antenna ports are defined by means of the irreducible representations of the symmetry group.