 # Radiofrequency Radiation Dosimetry Handbook

### (Fourth Edition) ## Chapter 6. Calculated Dosimetric Data

### 6.1. CALCULATED PLANEWAVE DOSIMETRIC DATAFOR AVERAGE SAR

Calculated dosimetric data for the average SAR of humans and various animals irradiated by planewaves with incident-power density of 1 mW/cm2 in free space are presented in Figures 6.1-6.30.
Figure 6.1 shows the average SAR for the six standard polarizations in an ellipsoidal model of an average man. The average SAR in ellipsoidal models of different human-body types, for EKH polarization, are compared in Figure 6.2.
Figures 6.3-6.19 show the average SAR for the three standard polarizations in prolate spheroidal and cylindrical homogeneous models of humans and test animals in the frequency range 10 MHz-100 GHz. These data were calculated by several different techniques, as described in Section 5.1.1 and shown in Figure 5.1. For frequencies below 10 MHz, the 1/f2 principle can be applied to the 10-MHz SAR data to determine SARs at lower frequencies. See Chapter 8 for a comparison of calculated and measured values.
The data in Figures 6.20-6.22 illustrate the effects of tissue layers on average SAR, in contrast to the data for homogeneous models in the previous figures. These data were calculated for a man model consisting of multiple cylinders, each cylinder representing a body part such as an arm or leg (Massoudi et al., 1979b). For a cylindrical model with layers that simulate skin and fat, the average SAR is different from the homogeneous models only for frequencies above about 400 MHz, where the wavelength is short enough that a resonance occurs in a direction transverse to the layers. The frequencies at which the resonances occur are primarily a function of the thicknesses of the layers and are not affected much by the overall size of the body. Figures 6.23 and 6.24 show the relationships between the frequency at which the peaks in average SAR due to the transverse resonance occur and the thicknesses of the layers.

Figures 6.25-6.30 show average SARs as a function of frequency for a few models irradiated by circularly and elliptically polarized planewaves.

#### Figure 6.30. Calculated planewave average SAR in a prolate spheroidal model of a medium rat irradiated by an elliptically polarized wave, for two orientations; a = 0.1 m, b = 0.0276 m, V = 3.2 x 10-4 m3. Go to Chapter 6.2

Return to Table of Contents.

Last modified: June 14, 1997
© October 1986, USAF School of Aerospace Medicine, Aerospace Medical Division (AFSC), Brooks Air Force Base, TX 78235-5301