Power lines continuously emit low frequency electromagnetic signals that can travel from the ground through the upper atmosphere and sometimes reach satellites in space. However, not all of the signals travel equally. Some are reflected back towards Earth or become too weak to detect, and the reasons behind these differences are still under investigation. This work focuses specifically on how the ionosphere affects the signals after it is generated by the power line source. Using detailed computer simulations, we examine how the signals move into and through the ionosphere, a region filled with charged particles such as electrons and ions interacting in the Earth's magentic field. The impact of some ions (such as H+ and He+) can strongly influence how the signal wave propagates, but this effect depends on the frequency of the signal. Including realistic altitudinal profiles of ions and electrons makes the model more accurate and helps explain why signals at some frequencies are observed more often than others in satellite data. These results can improve our understanding of how human-made electromagnetic signals interact with the ionosphere, which is important for space weather studies and radio communications.