Sub-wavelength UWB antenna array with fractal slots and split ring resonators for time reversal super-resolution focusing

Time reversal (TR) is a useful method that can focus electromagnetic waves precisely at the desired point in both time and space. In this paper, we find that properly designed and distributed micro-scatterers in the near-field zone of antenna array contribute to overcoming the diffraction limit. By directly integrating micro-structured fractal slots (FS) and split ring resonators (SRR) into each antenna element, a novel and linear array of CPW-fed UWB antennas is proposed to focus TR waves with a spatial super-resolution, in which the spacing between adjacent elements is 1/12 wavelength. With small dimensions of 29*43*32 mm³ and wide impedance bandwidth of 2.35GHz-11.5GHz, this proposed array is attractive for TR-UWB-MIMO communication applications.