# Slotted E-Shaped Meta-Material Decoupling Slab for Densely Packed MIMO Antenna Arrays
## 5 Conclusions  
A proficient method of including S-MM-DS is proposed for mutual coupling concealment in dense arrays with edge partition of 0.575 \(\lambda\)0. The S-MTM-DS structure was carved, drilled, and plated on a section between the radiating elements. The S-MM-DS is equipped for representing mutual coupling brought about by surface waves just as space waves. For 1.6 thick and 4.5 permittivity substrate the mutual coupling decrease of \(-43.7\) dB was accomplished with the decoupling slab set between array components. The structure is effectively feasible and can be utilized in all respects viably in beam scanning applications. The real advantage of this plan is that it tends to be effectively created and can be strategically located where the mutual coupling concealment is wanted. The S-MTM-DS is created from a similar material as that of exhibit components consequently making this system exceptionally adaptable in wording of its advantages and applications.  
Conceptualization, K.H.M. and H.G.M.; methodology K.H.M. and H.G.M.; software, K.H.M., A.S.I.A., M.M. and H.G.M.; validation, K.H.M., A.S.I.A., M.M. and H.G.M.; writing--review and editing, K.H.M., A.S.I.A., M.M. and H.G.M.; supervision, H.G.M. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
This research was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University through the Fast-Track Research Funding Program.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Ref**} & \multirow{2}{*}{**Method**} & **Max.** & **Patch** & **Operating** & **Average** & **Design** & **Cost** \\  & & **Isolation** & **Separation** & **Bandwidth** & **Percentage** & **Complexity** & **Cost** \\  & & **Improvement** & **(\(\lambda\)0)** & **Reduction (\%)** & & & & \\ \hline
[19] &
\begin{tabular}{c} Shorted annular \\ elliptical patch \\ Ring of magnetic \\ current \\ Complementary \\ split-ring resonators \\ meta-surface \\ wall isolator \\ Complementary \\ \end{tabular} & \(8\) (14\%) & 0.75 (16\%) & 81\% & 37\% & Moderate & Medium \\
[20] &
\begin{tabular}{c} Motion \\ current \\ Complementary \\ split-ring resonators \\ meta-surface \\ wall isolator \\ complementary \\ \end{tabular} & \(10\) (18\%) & 0.5 (25\%) & 87\% & 40\% & Moderate & Medium \\
[16] &
\begin{tabular}{c} Motion \\ split-ring resonators \\ meta-surface \\ wall isolator \\ complementary \\ \end{tabular} & \(37\) (65\%) & 0.125 (100\%) & 100\% & 88\% & High & High \\
[21] &
\begin{tabular}{c} Motion \\ split-ring resonator \\ meta-material decoupling slab \\ \end{tabular} & \(13.5\) (24\%) & \(1.16\) (11\%) & 100\% & 45\% & Low & Low \\
[17] &
\begin{tabular}{c} Motion \\ split-ring resonators \\ meta-material decoupling slab \\ \end{tabular} & \(27\) (47\%) & 0.125 (100\%) & 71\% & 73\% & Low & Low \\
[18] & \
\begin{tabular}{c} Motion \\ split-ring resonators \\ meta-material decoupling slab \\ \end{tabular} & \(17\) (30\%) & 0.75 (16\%) & 88\% & 45\% & Moderate & Medium \\ Proposed &
\begin{tabular}{c} Motion \\ split-ring resonators \\ decoupling slab \\ \end{tabular} & \(18\) (32\%) & 0.5 (25\%) & 100\% & 52\% & High & High \\
[18] & \
\begin{tabular}{c} Motion \\ split-ring resonators \\ meta-material decoupling slab \\ \end{tabular} & \(57\) (100\%) & 0.66 (19\%) & 100\% & 73\% & Low & Low \\ Proposed &
\begin{tabular}{c} Motion \\ split-ring resonators \\ meta-material decoupling slab \\ \end{tabular} & \(43.7\) (76\%) & 0.57 (22\%) & 100\% & 66\% & Moderate & Low \\ \hline \hline \end{tabular}
\end{table}
Table 3: Measurements resulted from the Three Isolating Techniques against previously presented work in the literature.