## 3 Results and Discussion
### Radiation Pattern Performance
#### 3.2.3 Beam Squint and Beamwidth Performance  
The boresight to 10 dB beamwidth ratio is known as beam squint. The boresight should be symmetrical if the beam squint is zero. The feeding network settings, the design of the patch or radiator, and the design of the antenna substrate can all determine the polarization of the antenna, which can influence the beam squint. Ideally, the beam squint is zero which means the boresight is symmetrical. Changes in the beam squint can be induced by changes in the polarization of the antenna, which can be caused by the feeding network settings,  
Figure 8: Side Lobe Level of (**a**). Element and 1 \(\times\) 2 Regular Palm Tree (RPT-CVA), 1 \(\times\) 2 Front Cut Palm Tree (FCPT-CVA), 1 \(\times\) 2 Middle Cut Palm Tree (MCPT-CVA), 1 \(\times\) 2 Back Cut Palm Tree (BCPT-CVA), 1 \(\times\) 2 Complete Cut Palm Tree (CCPT-CVA), 1 \(\times\) 2 Left Tilt Palm Tree (LTPT-CVA), 1 \(\times\) 2 Right Tilt Palm Tree (RTPT-CVA), 1 \(\times\) 2 Hilbert Fractal Structure Palm Tree (HFSPT-CVA), and (**b**). Element and 1 \(\times\) 2 Regular Palm Tree (RPT-CVA), 1 \(\times\) 2 Koch Fractal Structure Palm Tree (KFSPT-CVA), 1 \(\times\) 2 Exponential Slot Edge Palm Tree (ESEPT-CVA), 1 \(\times\) 2 Vertical Wave Structure Palm Tree (VWSPT-CVA), 1 \(\times\) 2 Horizontal Wave Structure Palm Tree (HWSPT-CVA), 1 \(\times\) 2 Regular Lens Palm Tree (RLPT-CVA), 1 \(\times\) 2 Elips Lens Palm Tree (ELPT-CVA), and 1 \(\times\) 2 Metamaterial Lens Palm Tree (MLPT-CVA). the geometry of the patch/radiator, and the shape of the antenna substrate. The squint beam will reduce the link budget due to the misalignment of the main beam [42]. Figure 9a shows the beam squint of the element and 1 \(\times\) 2 RPT, 1 \(\times\) 2 of FCPT, MCPT, BCPT, CCPT, LTPT, RTPT, and HFSPT-CVA. The simulation results that HFSPT has the worst performance at 0.5 GHz and 2 GHz. At 2 GHz the result of beam squint is 32,425\({}^{\circ}\) and \(-\)30.613\({}^{\circ}\) for 1 \(\times\) 2 HFSPT and 1 \(\times\) 2 RTPT respectively. Figure 9b describes the beam squint of the element and 1 \(\times\) 2 of RPT, 1 \(\times\) 2 of KFSPT, ESEPT, VWSPT, HWSPT, RLPT, ELPT, and MLPT-CVA. At 0.5 GHz 1 \(\times\) 2 KFSPT has the worst beam squint as shown in Figure 9b. Adding a corrugated slot can affect the beam squint as well as the return loss performance in the low-end frequency. The 1 \(\times\) 2 KFSPT also results in the beam squint of 32.87\({}^{\circ}\), 25.44\({}^{\circ}\), and 21.048\({}^{\circ}\) at 2 GHz, 2.5 GHz, and 3 GHz respectively. Figure 9b, found that ELPT results in the best beam squint performance, in all frequencies between 0.5 GHz to 4.5. However, the 1 \(\times\) 2 RPT element maximum Beamsquint is 3.28\({}^{\circ}\) at frequencies 0.5 and 4 GHz. Adding structure on. both edges of the patch can increase the gain but also affect the beam squint of the antenna. Figure 10 shows that the antenna has a large beamwidth at a frequency of 0.5 GHz, which decreases with increasing frequency. The largest beamwidth obtained by the ELPT-CVA structure at 0.5 was 78.5\({}^{\circ}\), while the smallest was by VWSPT-CVA at 41.41\({}^{\circ}\). The antenna beamwidth at 4 GHz frequency shows the smallest beamwidth of 3.32\({}^{\circ}\) for the ELPT-CVA structure. Although at a frequency of 0.5 GHz, the ELPT-CVA antenna has the largest beamwidth, the addition of an elliptical structure, with increasing frequency, makes the beamwidth smaller. The beam width variation across the 15 simulated antenna in 1 \(\times\) 2 MIMO configurations is modest at the 1-4.5 GHz frequency. Figure 10 illustrates that the single-element beamwidth is greater than the antenna in MIMO at all frequencies. Antennas in MIMO can increase beamwidth performance.