Executive Summary : | The Rayleigh scattering and Mie theory are significant milestones in electromagnetic elastic scattering, but laboratory and in situ experiments remain essential for studying particle scattering. Current scattering measurement techniques are divided into visible light scattering by particles with dimensions in the order of um and microwave scattering by cm and mm-sized objects. Optical methods provide empirical knowledge but sacrifice the exact knowledge of the physical inputs. Microwave instrumentation, although bulkier and less robust, enables precise measurement of complex scattered wavefronts. This project proposal aims to build a facility for measuring electromagnetic scattering at mm-wave frequency (50 GHz to 67 GHz) to address the inverse scattering problem. Current methods demonstrate rigorous measurements over a maximum number of angular orientations around scatterers, but this is time-consuming, increases hardware complexity, introduces drift error, and is not feasible for measurements of dynamic scattering and in-situ applications. The proposed project will identify and quantify relevant wave-matter interactions to engineer them for electrical circuit design. For example, the concept of toroidal modes and their superposition with other multipole modes leading to anapole states has been proposed for on-chip photonics and harmonic mixing. This fundamental principle of non-scattering electromagnetic configuration at radio frequency can be foreseen as a building block for receiving apertures of wireless power transfer and can be engineered for localized beams on a sub-wavelength scale. |