The transmittance values of the MS and dielectric WAIMs for all scan angles across the E, H, and D planes are compared in Fig. 12 at 4.0 GHz. It is interesting to find that the MS outperforms the dielectric WAIM across both the E and D planes and performs the same as the dielectric WAIM in the H plane. Previous works on single layer WAIMs based purely on the modification of the free space region above the array aperture are overwhelmingly carried out at a single frequency of operation. Therefore, to make a direct comparison to them, we compare in Table 1 the performance of the MS at 4.0 GHz to those reported in two key works in this area. The work in ref.31 only presents scanning across the H-plane for two designs. One scans up to 55° and another scans between 40° and 80°. It is shown here that the MS achieves wider scanning in both the E and H planes in comparison to the results reported in both ref.31,32. Moreover, it falls only 2° short of the D-plane scan in ref.32.Figure 12Comparison of the MS (solid lines) and dielectric WAIM (dashed lines) across the E, H, and D planes at a minimum of 80% transmittance (equivalent to VSWR < 3) at 4.0 GHz.Table 1Maximum Scan Range at a Single Frequency.Previous workThis workRef.31Ref.32DielectricMSE-PlaneN/A45°64°72°H-Plane55°65°80°80°D-PlaneN/A81°72°79°