Single-Element Beamforming Using Multi-Mode Antenna Patterns

Multi-mode antennas have recently been studied for communication as well as localization purposes. In this letter, the capabilities provided by a single planar multi-mode radiator as a steerable multi-port antenna are explored. As an original contribution, the radiation characteristics of individual groups of modes of the single radiator are combined to optimize beamforming performance. Three possible codebook realizations resulting from the optimization of gain, element factor, and, as a new criterion, gain by element factor are studied and compared. Numerical results show that the gain can be enhanced by about 3 dB at some angles.