It can be overwhelming to think about how our lives are impacted by the utilization of radio frequency (RF) technology. I could also see several hundred antennas from the window. It appeared that I had 10 radio frequency identification (RFID) devices in my pockets, five radio receivers and three radio transmitters in my smartphone, one transmitter in my ignition key and three dozen antennas in my home. Have you ever tried to count the number of wireless devices you use every day? How many antennas, radio receivers and radio transmitters you have in your pockets? I tried to do it. These formulas do not take into account other factors influencing the RF signals propagation, for example, absorption, polarization, scattering, reflection, and diffraction, which are described below.Ĭell Phone Signal Underground Propagation? These formulas are used in our calculator. To get the total radio horizon d of the receiving and transmitting antennas (or effective communication range between the two antennas) their radio horizons are added: The distance d₂ from a receiving antenna to the horizon can be calculated using the same formulas. Therefore, we can rewrite the formula above as If we consider the effect of the atmosphere on the propagation of RF signals, the Earth’s radius and hence the radio horizon can be increased by the factor of 4/3 or about 33%. Because of the refractive effects of atmospheric layers with different temperatures under normal conditions, RF signals propagate not in straight lines they bend towards the Earth surface and can propagate over the horizon. The equations above do not take into account the effect of the atmosphere on the propagation of VHF and UHF signals. Note that the dimensions of h, R and d must be in the same units (e.g. H₁ is the transmitting antenna height above the ground, For a perfect sphere without any mountains, the distance d₁ from a transmitting antenna to the horizon or the line of sight, or radio horizon, can be calculated from the Pythagorean theorem (see the picture above):