## 4 Prototype, Measurements, Discussion and Assessment of Results  
The prototype of the proposed design before and after alignment with necessary stacking and bonding is shown in Figure 9a. The measurement of S\({}_{11}\) using VNA (Vector Network Analyzer) and other radiation parameters (gain, AR, and radiation patterns) are took place in an anechoic chamber, as shown in Figure 9b,c. The deviations in measured results compared to the simulation results are due to the manual soldering of the connector to the ground and the bonding losses of the DR layers with the substrate. The comparisons of the measured and simulated S\({}_{11}\) and AR plots are presented in Figures 10 and 11, respectively. The measured broad bandwidth of 1.837 GHz (4.46-6.297 GHz) and a wide 3 dB axial ratio bandwidth of 750 MHz (4.72\(-\)5.49 GHz) are achieved with the proposed Minkowski\(-\)shaped metasurface and an optimized feed location for the DR configuration. Figure 12 provides the gain versus frequency plot of the proposed HCDRA, where the measured gain obtained is 7.04 dBic across the offered frequency range from 4.46 to 6.297 GHz. The patterns in the XZ and YZ planes are similar and in close agreement with the simulated results, as shown in Figures 13-15. The change in patterns with respect to the frequency has been given in Figures 13-15, which includes 3D radiation patterns, and hence it is observed from the patterns that the gains are consistent across the bandwidth obtained. The lower part of the measured radiation deteriorates due to the substrate's two-layer bonding (with NITTO tape) and soldering losses. The simulation and measured results are summarized in Table 1.  
Figure 8: S\({}_{11}\) plots for different lengths of probe feed (ph). Figure 10: Simulated vs. measured S\({}_{11}\) plots of proposed HCDRA. Figure 9: Measurement of HCDRA (**a**) fabricated prototype; measurement of (**b**) S\({}_{11}\) using VNA, and (**c**) radiation parameters in an anechoic chamber setup. Figure 11: Comparison of simulated and measured AR (dB) plots of HCDRA. Figure 12: Gain vs. frequency plot. Figure 14: **(a)** Three –dimensional (3D) radiation pattern, simulated vs. measured (b) XZ and (c) YZ plane radiation plots at 4.9 GHz. Figure 13: **(a)** Three –dimensional (3D) radiation pattern, simulated vs. measured (b) XZ and (c) YZ plane radiation plots at 4.7 GHz. Figure 15: **(a)** Three –dimensional (3D) radiation pattern, simulated vs. measured (b) XZ and (c) YZ plane radiation plots at 5.25 GHz. The performance of the proposed HCDRA is compared with the existing literature, which is given in Table 2. The methodology used to generate CP in [15; 16] is due to the feed and the feed mechanism combination, i.e., the DR elements' placement. The quasi-self-complimentary nature of the metasurface is accountable for CP radiation [17], and the slotted rectangular array of unit cells given in [20] is responsible for splitting the CP radiation into dual CP bands, respectively. The operating frequencies are within the range of millimeter wave (5G-NR-FR2) and sub 6 GHz (5G-NR-FR1) applications. The type and size of the substrate, metasurface, size, and shape of the proposed DRA differ from the work reported in [21]. The asymmetric nature and location of the probe feed (indirectly, it relates to the diameter of the DR element) on the metasurface are accountable for CP radiation. The gain is steady across the bandwidth of the proposed work compared to the other reported works presented in Figure 8:0 \begin{table}
\begin{tabular}{c c c} \hline \hline
**Parameter** & **Simulated Results** & **Measured Results** \\ \hline Operating frequency band & 4.24–5.7525 GHz & 4.46–6.297 GHz \\ \hline RL bandwidth & 1.5125 GHz & 1.837 GHz \\ \hline AR bandwidth & 0.56 GHz & 0.75 GHz \\ \hline Gain & 6.92 dBi & 7.04 dBi \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Summary of simulation and measured results of proposed HCDRA. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**[Ref. ]** & \