Single-Pixel Scanning Near-Field Imaging With Subwavelength Resolution Using Sharp Focusing Mikaelian Lens

Abstract

Obtaining sharp focusing with high resolution is of significant importance to microwave and millimeter-wave imaging and sensing. Here, we propose an all-dielectric surface focusing Mikaelian lens operating at the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$X$ </tex-math></inline-formula> - and Ka -band, respectively, with the high-resolution focusing of theoretical full-width half-maximum (FWHM) around <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.45\lambda $ </tex-math></inline-formula> for the single-pixel scanning microwave and millimeter-wave imaging. Benefitting from easily accessible 3-D printing, the designed lens prototype with perforation and infill structure can be fabricated at a very low cost. Moreover, numerical simulations and the spatial resolution imaging experimental results demonstrate that the proposed lens prototype exhibits excellent imaging performance with a subwavelength resolution of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\sim 0.5\lambda $ </tex-math></inline-formula> while maintaining broadband behavior, revealing great potential for high-resolution microwave and millimeter-wave imaging applications.