In this paper we present the full process of designing anisotropic metamaterial (MM) wide angle impedance matching (WAIM) layers. These layers are used to reduce the scan losses that occur in active phased arrays for large scanning angles. Numerical results are provided to show the improvement in performances that such layers can ensure. The proposed anisotropic MM-WAIM layers achieve an improvement of about 1 dB of more radiated power at θ= 70 from broadside, in a 13% of fractional bandwidth on the azimuthal plane Φ= 90. Weaker improvements are obtained in the other azimuthal planes, however keeping the active reflection coefficient below-9 dB for all azimuthal planes up to θ= 60 and up to θ= 70 off-axis for planes Φ= 45; 90 in the whole operational band.