Aspects of the present disclosure provide an improved material structure for a human body model. The human body model comprises (1) a first layer comprising a first material, (2) a second layer, comprising a second material, underneath the first layer, and (3) a third layer, comprising a third material, underneath the second layer. The dielectric constant of the second material is less than a dielectric constant of the first material and less than a dielectric constant of the third material. According to an aspect, the thickness of the first and/or second layer may represent the thickness of human skin and fat, respectively. The thickness of one or more layers may vary based on a location on the human body model.
