Sub-wavelength focusing and imaging using shifted-beam and super-oscillation antenna arrays

We review our recent research on the development of structures that can focus electromagnetic waves down to sub-wavelength spots for detection and imaging applications. Emphasis is placed on increasing the “working distance” from the focusing apparatus. For this purpose, we have developed optimized near-field antennas arrays (“meta-screens”) that are designed using the notion of the “shifted beams”. We have also developed super-oscillation antenna arrays that do not utilize evanescent waves and thus can increase the working distance at the multi-wavelength range. Example applications in imaging and detecting buried objects as well as in superresolving radars are presented.