Microwave Near-Field Synthesis for 2-D Shaped Power Dissipation Distribution Inside Layered Media by Weighted Projections of Refracted Plane Waves

This letter presents a novel analytical near-field synthesis method for 2-D shaped power dissipation inside a multi-layered medium using a planar radiating array. The method establishes a mapping between the projection weights of refracted plane waves inside a multi-layered medium and the spatial spectra of the electric field related to the desired 2-D power dissipation distribution. These refracted waves and their projections on the plane where the buried target is located can be analytically derived using the array-based near-field plane wave approximation. Based on this mapping, the proposed method utilizes the Fourier transform to analytically compute the required array excitation to generate the desired power dissipation distribution, thus avoiding time-consuming iterative optimization. Simulation results show that, compared with the element-based plane wave approximation method, the proposed method yields significantly improved 2-D shaped power dissipation distribution inside a layered medium close to the planar radiated array.