# Advanced Metamaterial-Integrated Dipole Array Antenna for Enhanced Gain in 5G Millimeter-Wave Bands
## 3 Antenna Results and Discussion
### Performance Comparison  
The performance comparison of the proposed metamaterial-based millimeter-wave antenna with similar available mm wave antennas from the literature is presented in Table 5. The performance is compared in terms of the type of antenna design, antenna volume, center frequency, bandwidth, radiation direction, peak gain, and substrate layers. Several antenna designs are reported in the literature to boost the performances of millimeter-wave antennas [17; 18; 19; 20; 21; 22; 23; 24; 25; 26]. The reported antennas in [17; 18; 20; 24; 25; 26] are designed on a single layer, while [10; 25] offer wide operating bandwidths. However, all of these antennas suffer from very low antenna gain, especially the antennas in [24] and [25]. Similarly, the antennas in [21; 22; 23] and [27] suffer from the requirement of multi-substrate layers and offer narrow functional bandwidths. In contrast, our proposed metamaterial-based antenna offers a very high antenna gain of 11.21 dBi with a wide operating bandwidth of 63.92%. The performance parameters of the proposed antenna, high gain, wide bandwidth, and especially the end-fire radiation characteristics, make it a strong contender for wideband millimeter-wave 5G applications.  
Figure 12: Simulated and measured gain, and radiation efficiency performance: (**a**) antenna without metamaterial structure and (**b**) antenna with metamaterial structure.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Refs.** & **Antenna Type** & \multicolumn{2}{c}{**Total Antenna Size**} & \multicolumn{2}{c}{**Center Freq.**} & \multicolumn{2}{c}{**BW (\%)**} & \multicolumn{2}{c}{**Radiation**} & \multicolumn{2}{c}{**Peak Gain**} & \multicolumn{2}{c}{**Substrate**} \\  & & \multicolumn{2}{c}{**(A \(\times\) A \(\times\) A)**} & \multicolumn{2}{c}{**(GHz)**} & & \multicolumn{2}{c}{**Direction**} & \multicolumn{2}{c}{**(dBi)**} & \multicolumn{2}{c}{**Layers**} \\ \hline
[17] & Quasi-Yagi & 5.88 \(\times\) 4.22 \(\times\) 0.07 & 28 & 9.64 & Broadside & 9.8 & Single \\
[18] & Planar series-array antenna & 6.07 \(\times\) 1.24 \(\times\) 0.015 & 26 & 15.38 & Broadside & 10 & Single \\
[20] & Log-periodic dipole array + director cell & 2.49 \(\times\) 1.51 \(\times\) 0.05 & 30.5 & 58.46 & End-fire & 10.95 & Single \\
[21] & Multi-layer planar segmented antenna & 1.213 \(\times\) 1.213 \(\times\) 0.113 & 28 & 21.6 & Broadside & 11.5 & Double \\  & (ISA) & Metasurface-integrated dipole & 2.76 \(\times\) 2.76 \(\times\) 2.78 & 30.5 & 21.5 & End-fire & 11 & Single + 2 layers of metasurface \\  & Dielectric-loaded stepped slot antenna + & 1.31 \(\times\) 0.75 \(\times\) 0.39 & 37.5 & 23.6 & End-fire & 7.2 & Double \\  & substrate-integrated waveguide (SIW) & 1.31 \(\times\) 0.75 \(\times\) 0.39 & 37.5 & 23.6 & End-fire & 7.2 & Double \\
[24] & Planar antenna with defective ground + & 2.8 \(\times\) 1.4 \(\times\) 0.03 & 28 & 29.82 & Omnidirectional & 6.49 & Single \\  & (25) Ring-shaped patch with slotted ground & 0.77 \(\times\) 1.21 \(\times\) 0.028 & 33 & 42.4 & Omnidirectional & 5.36 & Single \\
[26] & Clover antenna array & 3.6 \(\times\) 0.347 \(\times\) 0.05 & 26 & 32.6 & Broadside & 9 & Single \\
[27] & Printed antenna + Metamaterial Layer & 1.68 \(\times\) 2.05 \(\times\) 1.65 & 27.96 & 5.9 & Broadside & 11.94 & Double + 1 foam layer \\
**This work** & **Non-uniform dipole array with metamaterial** & **2.98 \(\times\) 0.93 \(\times\) 0.019** & **33.95** & **63.92** & **End-fire** & **11.21** & **Single** \\ \hline \hline \end{tabular}
\end{table}
Table 5: Performance comparison of proposed metamaterial-based high-gain mm wave antenna.