## 4 Experimental Result
### The VNA Graphics of Tests Performed on 5W Ground Plane Transmission Line  
In transmission line analysis, identifying aggressor and victim lines is essential for understanding crosstalk behavior. The aggressor line is the one to which the signal is applied, emitting noise and interference to surrounding lines, while the victim line is affected by this interference and maintains its current state.  
This section presents measurement findings for a transmission line with a ground plane width five times that of the signal line (5W). To minimize the effects of production errors and variations in electronic circuit boards, experiments were conducted in different regions on the same panel. Similar to the previous section, measurements were performed for transmission line lengths of 100 mm and 200 mm. These experiments specifically focused on S\({}_{31}\), which plays a critical role in the performance and stability of the transmission line.  
The capacitors were placed at three positions along the 100 mm transmission line to evaluate the effects of capacitive interactions on signal integrity. The results are presented in Figure 8, with Figure 8a showing the beginning placement, Figure 8b the midpoint placement, and Figure 8c the endpoint placement.  
Figure 8: The NEXT obtained when capacitors with values of 1 pF, 15 pF, and 82 pF are placed in length of 100 mm and a ground width of 5W: (**a**) at the beginning of the transmission line; (**b**) in the middle of the transmission line, and (**c**) at the end of the transmission line.  
According to the graphs in Figure 8, the placement of capacitors significantly impacts crosstalk reduction on the 100 mm transmission line. At the beginning of the line, 15 pF and 82 pF capacitors demonstrate improvements between 1.3 GHz and 1.6 GHz. For capacitors placed at the midpoint, all values show positive effects around 1.6 GHz, with 15 pF and 82 pF providing improvements of up to 20 dB. At the endpoint, 15 pF and 82 pF capacitors similarly achieve up to 20 dB improvements in the 1.3-1.6 GHz range. Notably, the 15 pF capacitor achieves a peak improvement of 25 dB around 2.1 GHz.  
For the 200 mm transmission line model, the capacitor placements are presented sequentially in Figure 9, with Figure 9a showing results for the beginning placement, Figure 9b for the midpoint, and Figure 9c for the endpoint.  
According to the graphs in Figure 9, capacitors placed at different positions on the 200 mm transmission line exhibit significant crosstalk reduction effects across various frequency ranges. At the beginning of the line, 15 pF and 82 pF capacitors provide an improvement of approximately 25 dB around 1.9 GHz, while a 1 pF capacitor achieves an improvement of 30 dB around 2.4 GHz. When capacitors are placed at the midpoint of the line, 15 pF and 82 pF capacitors deliver improvements of up to 30 dB across nearly the entire range of 1.35 GHz to 2.5 GHz.  
At the endpoint, 15 pF and 82 pF capacitors provide improvements over a wide range from 650 MHz to 3.1 GHz, with enhancements reaching up to 40 dB. Additionally, the  
Figure 9: The NEXT obtained when capacitors with values of 1 pF, 15 pF, and 82 pF are placed at length of 200 mm and a ground width of 5W: (**a**) at the beginning of the transmission line; (**b**) in the middle of the transmission line, and (**c**) at the end of the transmission line.  
1 pF capacitor demonstrates improvements of up to 35 dB in the range of 2.9 GHz to 3.1 GHz. These results highlight the importance of both capacitor selection and placement in mitigating crosstalk and maintaining signal integrity across diverse frequency bands.