Design of Rectangular Waveguide-fed Metasurfaces for Near-Field Shaping using a Coupled Dipole Model

We present the design of rectangular waveguide-excited metasurfaces for near-field shaping using a coupled dipole framework. Waveguide-fed metasurfaces are array-like radiating systems typically constructed from one or more waveguides loaded with a series of subwavelength metamaterial apertures that function as radiators. The use of subwavelength radiating elements distributed across the aperture enables electromagnetic field control with subwavelength precision, offering significant potential for near-field shaping. Leveraging these capabilities, we demonstrate that the near-field patterns of rectangular waveguide-fed metasurfaces can be tailored using the coupled dipole model, which accounts for mutual interactions between metamaterial radiating elements. The validity and effectiveness of the proposed approach are verified through full-wave simulations and experiments in the X-band.