Comparison of Semi-anechoic Chamber and Open-field site Attenuation Measurements

Abstract

The results of vertical and horizontal site atten­ uation measurements performed in a variety of semianechoic chambers over the 30-200 MHz frequency range are presented. In order to demonstrate the operation of these chambers below the frequency range where their RF absorber is completely effective, these measurements are compared to the site attenuations of an open-field. The effect of varying the location of the transmit antenna is included. The use of site attenuation mea­ surements for correlating semi-anechoic chamber and open-field EMI measurements is also discussed.