An important aspect to consider when modeling RF absorption by the human head is the frequency of the signal. At lower frequencies, RF energy tends to penetrate deeper into the skin, while at higher frequencies (such as millimeter-wave), the energy is absorbed more superficially and cannot penetrate more than several millimeters into the skin. The human head contains a variety of tissues with different dielectrically properties. These tissues, including the skin, bone, and brain, all absorb RF energy to varying degrees, and their relative contribution to the overall absorption depends on the frequency of the RF signal. It's important to note, that more complex model will inevitably lead to longer simulation time and memory consumption, so a trade-off between accuracy and speed is often required.