In this Section a problem of impedance synthesis for a 2D antenna arrays consisting of narrow linear slots with magneto-dielectric filling is solved. The slots are cut in a perfectly conducting screen, which geometric centers coincide with nodes of a rectangular grid with double periodicity. The slots are excited by voltage δ-generators in the center of the slot apertures. The slot cavities are represented by rectangular resonators with magneto-dielectric filling which control the induced magnetic impedance of the radiators by varying the material parameters of the slots filling. The problem solution is based on the approach proposed by the authors for the impedance synthesis of vibrator arrays (Chap. 6 ) and based on the electrodynamic principle of permutation duality (Sect. 1.4.2 ).