## 3 Results and Discussion
### Antenna Array with BM Network
For instance, if a signal is fed to port 1 of the antenna and a wireless device worn by the miner connects to the beam in the direction of \(27^{\circ}\), the antenna continuously tracks the device as it moves along the tunnel. Once the miner moves out of the range of beam 1, the connection switches to beam 4, fed by port 4, at an angle of \(16^{\circ}\). Likewise, beam 3 connects to the device at \(-12^{\circ}\), and beam 2 provides coverage at \(-26^{\circ}\), as shown in Figure 21. This dynamic beam steering capability, common in BM-based systems, allows for seamless connectivity and tracking in confined environments like tunnels [97]. This approach also significantly reduces multipath signals, enhancing the signal-to-noise ratio and minimizing interference compared to traditional omnidirectional antennas. Additionally, the antenna exhibits circular polarization characteristics, which help mitigate polarization mismatches and enhance signal strength, a  
Figure 19: Reflection coefficient of the BM for all input ports (1–4) when each port is excited at a time. feature that is especially advantageous in environments prone to signal degradation due to physical obstructions [98]. The proposed antenna's performance can be compared to previous studies, demonstrating its advancements in both beam steering and polarization capabilities. For instance, [PERSON] [99], discussed a monopole array capable of beam steering, but its design was limited to only four specific angles (\(-45^{\circ}\), \(-15^{\circ}\), \(15^{\circ}\), and \(45^{\circ}\)). While this early work contributed to the development of beam steering technologies, the monopole array lacked the flexibility and sophistication needed for complex environments like underground mines. The absence of circular polarization in [PERSON]'s monopole array constrained  
Figure 21: Visualization of the miner with beam steering of the antenna. Figure 20: Far-field radiation pattern of the proposed antenna with Butler matrix when (**a**) port 1, (**b**) port 2, (**c**) port 3, and (**d**) port 4 are excited. its adaptability in environments prone to signal reflections and polarization mismatches, which are frequent in underground mining as indicated by [PERSON] et al. [100]. Similarly, [PERSON] and [PERSON] [101] presented a rectangular patch array with beam steering at the same four angles. However, their work did not consider waveform polarization or propose an antenna structure that could handle circular polarization. In dynamic environments where signal reflections are common, circular polarization is essential for minimizing polarization mismatches, thus maintaining consistent signal strength. Without circular polarization, their rectangular patch array faced limitations in its ability to handle complex signal environments, unlike the proposed antenna, which offers beam steering along with circular polarization capabilities [102] ([PERSON] & [PERSON], 2022). Additionally, [PERSON] et al. [103] described a dipole antenna array with beamforming capabilities, but their array was limited by its linear polarization. Linear polarization, while useful in some applications, is particularly vulnerable to signal loss and interference when there are multiple reflections or obstructions. This is especially true in underground mining environments, where the signal is likely to encounter various obstacles such as rock walls. Linear polarization often results in degraded signal quality under such conditions, while circular polarization offers greater robustness against these challenges. The proposed antenna, by leveraging circular polarization, ensures stronger signal integrity in these challenging conditions and provides superior performance compared to the dipole arrays used in previous studies [104]. The key distinguishing factor of the proposed antenna lies in its dual functionality, combining beam steering with circularly polarized waveforms.