Modeling Metamaterial Element in Dielectric-filled Waveguide-fed Metasurface Antennas

We study the modeling of metamaterial elements etched into planar, dielectric-filled waveguides for metasurface antennas. Metamaterial elements in these devices are subwavelength-sized, resonant openings embedded in waveguide walls-that can be modeled as the electric and magnetic dipoles-and couple to waveguide modes and radiate into free space. Due to a dielectric filling the waveguide, the dipole moments representing the element can contribute unequally to the scattered fields into the waveguide and the radiated fields into free space. Such different dipole strengths need to be considered for analytic modeling of metasurfaces. In this work, we present a retrieval of dipole moments of a metamaterial element by applying the law of power conservation and demonstrate its utility in the analytic model for the metasurface antennas.