Dual-Mode Metamaterial with Backward and Forward Wave Selectivity

In this paper, a mode selective metamaterial which supports either forward or backward waves within the same frequency bandwidth is presented. The choice between dispersion operations is based on the mode excitation applied to the metamaterial. A demonstration microstrip prototype of this novel dual-mode composite right/left-handed metamaterial is realized and characterized. The metamaterial is right-handed under even-mode excitation and is left-handed under odd-mode excitation in the 1.86 GHz -2.00 GHz frequency range. Circuit simulations with the numerical and experimental results of the dual-mode metamaterial transmission line are performed to demonstrate electromagnetic wave steering and spatial multiplexing at a fixed frequency based on dispersion selectivity.