## 3 Results
### Discussion  
The results presented in Figure 3(a) show that the measured reflection coefficients for both the LaYUA and TuSA antennas align well with the simulated results. This suggests that the designs of these antennas are robust and their performance characteristics in real-world conditions closely match theoretical expectations. Furthermore, the bandwidth of approximately 300 MHz for the LaYUA antenna is particularly advantageousfor various applications within the 2.4 GHz frequency range, as it ensures stable communication across a wide spectrum. In contrast, the TuSA exhibits a much wider bandwidth, which could contribute to its more stable performance over varying environmental conditions and distances.  
The simulated and measured radiation patterns on the azimuth plane (\(\phi\) = 90\({}^{\circ}\)) shown in Figure 3(b) agree very well within the half-power beamwidth for both antennas, thus, the simulated antenna characteristics are verified.  
The high directivity of the LaYUA antenna plays a critical role in its superior performance, particularly in scenarios requiring long-distance communication. Directivity, in this case, refers to an antenna's ability to focus the signal in a specific direction, thus minimizing energy loss and enhancing the effective signal strength at the receiving end. This is clearly demonstrated in Scenario 4, where the use of the LaYUA at the transmission unit (TxU) significantly improves the overall system performance compared to the baseline configuration (Scenario 1). The reduced bit error rate (BER) across increasing distances demonstrates the advantage of this high-gain antenna for long-range applications.  
In contrast, the commercial dipole antennas used in Scenario 1 are omnidirectional, meaning they radiate energy equally in all directions. While this provides coverage over a wider area, it also dilutes the signal strength in any specific direction, leading to a higher BER as the distance increases. At 60 m, the BER for Scenario 1 reaches approximately 90%, whereas Scenario 4 (the LaYUA and TuSA combination) maintains a BER of only 10%. This drastic improvement highlights the importance of using antennas with focused radiation patterns for long-distance wireless communication.  
The benefits of using the LaYUA in combination with the TuSA include the high directivity of the quasi Yagi-Uda structure, which enables long-distance communication and has the best performance, as shown in Figure 5. Additionally, the circular polarization characteristic of the TuSA reduces the need for exhaustive polarization calibration to ensure a clear line of sight.  
The better performance of Scenario 4 in Figure 5 can be attributed to the combined characteristics of the utilized radiators. Both Scenarios 2 and 4 employ the LaYUA, known for its high directivity, which significantly enhances signal focus. However, Scenario 4 is further enhanced by the inclusion of a turnstile antenna, which is polarization-independent due to its circular polarization [15]. This combination leverages the high directivity of the LaYUA at the TxU and the polarization versatility of the TuSA at the RxU, resulting in the best bit error rate performance across all tested scenarios.  
In Scenarios 2 and 3, where only one custom antenna is used, the performance is still markedly better than the baseline, but not as good as when both custom antennas are used. This suggests that while each antenna independently offers performance improvements, the combination of both the high-directivity LaYUA and the polarization-independent TuSA offers the most significant benefits. At 80 m, Scenario 4 maintains a BER of about 40%, whereas Scenario 1 approaches 100% and Scenario 3 reaches 90%. This underscores the complementary nature of the LaYUA and TuSA antennas in enhancing communication's reliability and range.