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Abstract
Spheres composed of
phantom muscle of radius 1.5, 2, 3, 4, 6 and 8 cm, as well as birds
(parakeets, quail, pigeons, chickens, turkeys) were exposed to far field
plane waves at power densities of incident radiation between 182 and 560
mW/cm² and at frequencies of 775, 915 and 2450 MHz. Specific absorption rate
(SAR) patterns were determined by thermographic
techniques for both spheres and birds. The measured SAR patterns in spheres
were comparable to those from theoretical predictions. The SAR patterns in
birds, however, varied markedly from those obtained from spheres of comparable
mass. The results indicate that the geometrically complex animal is not
represented by simple geometric models for making absorption studies. Thermograms of birds exposed in the flying position
indicated that the SAR is high in the wings. The behavioral
response of the birds to the exposure was variable. Threshold power densities
for biological or behavioral reactions were
determined for each bird at all three frequencies. The lowest power density
associated with reactivity by the chicken was 5.8 mW/cm² (corresponding to SARs of 3.1 W/kg in the head and 3.9 W/kg in the neck) at
775 MHz.
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