Analysis of composite walls for short path propagation modeling

SAR affected by shapes and electrical properties of the human head exposed to a cellular phone

“…1), the hand wraps around three sides of the lower half of the cellular phone and consists of a core of bone surrounded by a layer of muscle. The equivalent dielectric constant r , conductivity , and mass density of the hand ( r ϭ 39.6, ϭ 0.58 S/m, ϭ 1.04 g/cm 3 ) and ( r ϭ 32.45, ϭ 0.785 S/m, ϭ 1.04 g/cm 3 ) are obtained by assuming volume fractions of 0.5, and 0.5 for the muscle and bone, at 900 and 1800 MHz [2][3][4][5][6], respectively. Inside the box, an equivalent material obtained by the effective material property technique [2] is considered to model many printed circuits and air.…”

“…The equivalent dielectric constant r , conductivity , and mass density of the hand ( r ϭ 39.6, ϭ 0.58 S/m, ϭ 1.04 g/cm 3 ) and ( r ϭ 32.45, ϭ 0.785 S/m, ϭ 1.04 g/cm 3 ) are obtained by assuming volume fractions of 0.5, and 0.5 for the muscle and bone, at 900 and 1800 MHz [2][3][4][5][6], respectively. Inside the box, an equivalent material obtained by the effective material property technique [2] is considered to model many printed circuits and air. The relative dielectric constant and conductivity of the equivalent material inside the handset box ( r ϭ 1.84, ϭ 3.72 ϫ 10 6 S/m) and ( r ϭ 1.73, ϭ 3.72 ϫ 10 6 S/m) are obtained by assuming volume fractions of 0.1, 0.4, and 0.5 for the metallic material, epoxy resin substrates, and air, at 900 and 1800 MHz, respectively [7].…”

“…A realistic and accurate near-field box model of a handheld cellular phone with a monopole antenna is used in the simulations. Inside the box, an equivalent material obtained by the effective material property technique [2] is considered in order to model many printed circuits, conducting wires, and air. Four different head models, including spherical, cubical, coarse, and realistic models, have the same volume of about 5100 cm 3 .…”

On the modeling of reflected energy from building faces in microcellular mobile radio planning tools

“…An exact expression for the ensemble average specularly reflected field is readily determined if we consider that (6) where is the dyadic plane-wave Fresnel reflection coefficient and is the line-of-sight field at the receiver from the image of the transmitter through the wall without any gaps. Therefore (7) where the average value of the telegraph function is derived in [9].…”

“…In any case, "homogenization" models that account for the internal structure of walls have been reported in the literature [6] and can be used to model reflection and transmission through certain types of interior walls, such as those made of plasterboard. On the other hand, surface impedance or geometrical discontinuities of large dimensions compared to the wavelength are far more likely to account for the observed experimental discrepancy.…”