## 3 Experimental Measurements
### Experimental Set-Up
Figure 7: Broadband Horn antenna DRH 18-E: (**a**) Frequency characteristics, (**b**) Directional characteristic. \begin{table}
\begin{tabular}{l l} \hline \hline
**parameter** & **technical data** \\ \hline
**frequency range** & 1 GHz \(\times\) 19 GHz \\
**dimensions** & 24.3 cm \(\times\) 20 cm \(\times\) 15.4 cm \\
**connector type** & SMA (50 \(\Omega\)) \\
**frequency-dependent characteristics** & absolute gain Gi [dBi] \\
**directional characteristic shape** & directional SCH, which narrows with \\  & increasing frequency \\ \hline \hline \end{tabular}
\end{table} 
Table 3: The technical data of the Horn antenna DRH 18-E.  
EM interactions. The surface of the phantom is covered with pigskin, and a pacemaker head is placed on the surface of the bust under the skin. The receiving probe is placed on the surface of the phantom's skin in position above the pacemakers both without and with pacemaker measurements. This sequential probe placement ensures accurate recording of EM interactions between the pacemaker, skin, and probe, which is crucial for understanding and evaluating the impact of these devices on the human body. To simulate a human body, we fill a human bust with saline to create a conductive internal environment. The head of the pacemaker is then placed in the chosen position, and a receiving probe is placed on the surface of the bust, ensuring proper positioning and connection. Before starting the measurement, we set the radiating device to 0.5 W and ensure the frequency is set to 1.8 GHz. We conduct the first measurement at a distance of 5 mm from the antenna and repeat the measurement 10 times for accuracy. Subsequently, we increase the distance from the radiating antenna to 15 mm, 50 mm, and 300 mm, repeating the measurement 10 times at each distance. This procedure allows us to verify measurement consistency and evaluate how the electric intensity vector changes with distance from the source. We measure the electric intensity vector values on the surface and under the skin layer of the human phantom during each 10-s interval. During the experiment we measure without the pacemaker in the position of its placement on the surface of the created phantom and in the same position with a CPM under the skin of the phantom. For all experimental measurements, we follow the specific procedure, enabling a direct comparison of the effect of the implanted device on the EM interactions in the tissue with the previous results. We are conducting measurements at a frequency of 1.8 GHz, which is the standard frequency for the LTE (Long Term Evolution) system. This frequency is important for realistic communication systems, ensuring the relevance of our measurements. To ensure accuracy, we set the total power of the radiating device to 0.5 W, considering potential power losses due to attenuation at the connectors. Each measurement is taken over a 10-s interval to gather detailed EMF data. After completing the measurements, we analyse the data to determine the effective value of the electric intensity vector on the surface and under the skin of the human phantom. Our goal is to evaluate the impact of the radiating device on EMF in this environment. Understanding the results of EM measurements involves converting the units of the measured signal to evaluate the intensity of the EMF accurately. This process includes several steps that transform the results from one form to another. To obtain the actual power level (dBm\({}_{r}\)) from the measured value (dBm\({}_{m}\)), we need to adjust for attenuation. We use a 20 dB attenuator to ensure that the readings reflect real conditions. Figure 9: Demonstration of the measuring set, (**a**) the overall view to measurement set, (**b**) location of CPM—front view, (**c**) location of CPM—side view. Then we convert the corrected real power value in dBm\({}_{\text{r}}\) to the equivalent in microvolt decibels (dB\({}_{\text{i}}\)V). The system impedance in ohms is set to 50 \(\Omega\) as for most RF systems by default.