## 3 Experimental Outcomes and Investigations  
The photolithography method was utilized in the fabrication process. Figure 8 shows the prototype layout photo of the suggested antenna in the top and back views. FR4, with a total size of 32 \(\times\) 30 \(\times\) 1.6 mm\({}^{3}\), and \(\varepsilon\pi\) = 4.4, tan \(\delta\) = 0.025 were used in the fabrication. Additionally, it was tested using a vector network analyzer (R&S ZVA 67) to show the reflection coefficient \(S_{11}\), as shown in Figure 9a. The VNA screenshot result of the tested antenna is illustrated in Figure 9b. The tested results show the antenna worked at the  
Figure 6: The L4 influence on antenna performance **(a)**\(S_{11}\); **(b)** AR.  
Figure 7: The W6 influence on antenna performance **(a)**\(S_{11}\); **(b)** AR.  
frequency band from 3.8-9 GHz (81.25%) with \(S_{11}\leq-10\) dB, while the simulated outcomes illustrate that the antenna is operated from 4 to 9 GHz. The two results display good matching between them, with some slight deviations between them due to the fabrication tolerance and SMA soldering process.  
The setup of the far-field results was conducted inside an anechoic chamber, as illustrated in Figure 10. A horn antenna operating at a suitable range of frequency and connected to an RF signal generator was utilized as a transmitter antenna. On the other hand, there was a suggested antenna (antenna under test), which was placed inside the same chamber on a supporter that could rotate 360\({}^{\circ}\) in both the elevation and horizontal planes. The antenna was connected to a spectrum analyzer to measure the received signal. Additionally, there was a motion controller that controlled the motion of the antenna. The overall equipment, such as the motion controller, spectrum analyzer, and RF generator, was controlled to be operated synchronously. The antenna rotated around its axis with a certain step and stopped for some seconds; on the other hand, the spectrum analyzer measured the received power at this angle during the stopping time. The suggested antenna was rotated in two planes \(xz\) (\(\varphi\) = 0\({}^{\circ}\)) and \(yz\) (\(\varphi\) = 90\({}^{\circ}\)) planes. The co- and cross-polarization results at 5.5 and 5.8 GHz are shown in Figures 11a,b and 12a,b, respectively. More than a \(-15\) dB difference between the two components was  
Figure 8: Fabricated prototype layout of suggested antenna.  
Figure 9: The \(S_{11}\) results of the suggested antenna: (**a**) simulated and measured (**b**) VNA screenshot.  
The gain of the antenna was measured, as illustrated in Figure 13. It ranged from 1.8 to 3.8 dBi at the designed frequency band with a peak of 3.6 dBi. Moreover, the AR was  
Figure 11: The radiation pattern normalized outcomes at 5.5 GHz (a) \(\varphi=0^{\circ}\); (b) \(\varphi=90^{\circ}\).  
Figure 10: The setup of the radiation pattern measurement.  
tested, as displayed in Figure 14, and the achieved 3 dB AR extended from 4.48-6.11 GHz (30.7%) with a reasonable trend between the two outcomes.  
Finally, the suggested design was compared with others to evaluate the novelty of the work, as presented in Table 2. The suggested antenna had a more simple design than [3; 10; 11], a more compact size than [5; 9; 13; 14; 15; 16; 17; 18; 19; 22; 23; 24; 25], a broader bandwidth than [2; 9; 10; 12; 15; 17; 19; 21; 22; 25], and a broader 3 dB AR than [9; 10; 12; 15; 19]. Finally, it was deduced that the suggested antenna could be applied in UWB, sub 6 GHz, and WLAN wireless applications.  
Figure 14: The antenna AR’s measured and simulated outcomes.  
Figure 13: The antenna’s realized gain.