## 3 The UWB-MIMO MTM-Based MAVA for Diversity Analysis
\begin{table}
\begin{tabular}{c} **Eff (\%) Port 2** \\ **Sim** \\ \end{tabular} \\ \hline
3.8 & 4.70/3.50 & 10.7/10.00 & 93.42 & 97.00 \\ \hline
5.2 & 3.20/2.80 & 4.03/3.00 & 97.58 & 98.19 \\ \hline
8.0 & 4.75/3.50 & 4.83/4.20 & 95.00 & 96.50 \\ \hline
10 & 4.10/3.90 & 4.88/4.50 & 93.42 & 92.00 \\ \hline
15 & 4.90/3.85 & 4.93/4.40 & 88.58 & 94.19 \\ \hline
20 & 7.25/6.90 & 9.5/6.85 & 97.42 & 98.00 \\ \hline
25 & 5.70/5.45 & 7.25/5.95 & 93.58 & 98.19 \\ \hline
29 & 5.40/5.00 & 5.78/5.20 & 91.50 & 98.00 \\ \hline
31 & 5.90/5.25 & 5.95/5.15 & 95.58 & 97.00 \\ \hline
34 & 5.70/4.95 & 5.90/5.01 & 91.50 & 98.00 \\ \hline
38 & 4.70/4.25 & 6.08/5.15 & 95.58 & 97.00 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: The performance of MTM- band MAVA with 8-ports at the resonance frequencies when ports 1 and 2 are active (Sim: Simulation, Meas: Measurement). Figure 21: Measured transmission coefficients of the UWB-MIMO antenna. ECC is low, there is a lot of isolation between each antenna pair. ECC may be calculated using the antenna's radiation pattern, as illustrated in Equation (6):  
\[\rho_{mm}=\frac{\left|\int\int_{0}^{4\pi}[\overrightarrow{F_{m}}(\theta,\varnothing )\times\overrightarrow{F_{n}}(\theta,\varnothing)]d\Omega\right|^{2}}{\int \int_{0}^{4\pi}\left|\overrightarrow{F_{m}}(\theta,\varnothing)\right|^{2}d \Omega\int\int_{0}^{4\pi}\left|\overrightarrow{F_{n}}(\theta,\varnothing) \right|^{2}d\Omega} \tag{6}\]  
where \(\rho_{mm}\) is the value of ECC between the \(m\) and \(n\) ports, \(\overrightarrow{F_{m}}(\theta,\varnothing)\) is the radiation patterns of the antenna. In this work, \(n\) and \(m\epsilon\{1,2,\cdots,8\}\). The diversity gain (DG), on the other hand, is the process of selecting the strongest signal out of a set of N signals. The Equation (7) is used to determine it [73]. \[DG=10\sqrt{1-\left(ECC\right)^{2}} \tag{7}\]  
Figure 22 shows the ECC values of the MIMO antenna elements when using the 3D radiation of each element. It should be noted that in each situation, a pair of MIMO components is taken into account. Because of the orthogonality of the polarization between the two neighboring antennas, very minimal ECC values are obtained, as predicted. The ECC \(\leq\) 0.01 demonstrate that the eight-ports MIMO antenna offers strong diversity performance. (The ports shown in Figure 22 were chosen as samples) (Table 5). Figure 22: ECC alteration between port 1 and other seven ports (e.g., P\({}_{12}\): ECC between Port 1 and Port 2). Since the ECC value is \(|\rho|\leq 0.3\), it can be assumed adequate to produce high diversity gain in a MIMO antenna array system. One of the most significant diversity performance assessment metrics for MIMO antennas is channel capacity loss (CCL). It refers to the highest possible information transmission rate at which the signal may be easily transmitted without substantial loss. The following Equation (8) [73] can be used to determine the CCL. \[\text{CCL}=-log_{2}\text{det}(A) \tag{8}\]  
where,  
\[A=\left[ \begin{array}{ccc}a_{11}&\cdots&a_{18}\\ \vdots&\ddots&\vdots\\ a_{81}&\cdots&a_{88}\end{array} \right],\ a_{ii}=1-(\sum_{j=1}^{M}\lvert Sij \rvert^{2}),\ a_{ij}=-\bigl{\lvert}S_{ii}*S_{ij}+S_{ji}*S_{jj}\bigr{\rvert}.\]  
Figure 23 depicts the CCL calculated for the proposed antenna. At most frequency bands, the estimated CCL is almost half of the typical value of 0.4 bits/s/Hz for a realistic MIMO antenna system.