In previous work, we developed a model to predict theoretically the lo
w-frequency plane-wave reflection coefficient of an array of pyramid c
one absorbers such as those used to line anechoic electromagnetic meas
urement chambers, In this paper, we apply this model in a geometrical
optics approach to predict the electromagnetic field in a chamber line
d with cone absorbers in the frequency range of 30-300 MHz. The result
s are compared with site attenuation measurements for two actual semi-
anechoic chambers.