GEORGIA INST OF TECH ATLANTA ENGINEERING EXPERIMENT STATION
This report summarizes the accomplishments on a program to develop improved electromagnetic field probes, measurement techniques, and measurement procedures for performance radiated measurements in shielded enclosures over the 20 to 200 MHz frequency range. A set of three electromagnetic field probes to cover the 20 to 200 MHz frequency range was developed and evaluated. The results from the evaluation of the probes indicate that the set of improved probes is capable of providing significantly improved performance over probes currently in use for radiated measurements in shielded enclosures over the 20 to 200 MHz frequency range. The development and evaluation of a lossy-wall measurement technique are described. This technique requires coating the inside walls of the shielded enclosure with a lossy material to reduce the Q of the interior of the enclosure. The results from an evaluation of this measurement technique indicate that it reduces the maximum measurement error by more than 20 dB both above the lowest resonance of the enclosure, where resonance coupling predominates, and below the lowest resonance, where wall coupling predominates.