An analytical and experimental comparison of radiated emissions test facilities

Radiated emissions measurements are usually required to be performed on a facility that meets the normalized site attenuation (NSA) and receive antenna scan height requirements of ANSI C63.4 and CISPR 22. However, often preliminary measurements for the purpose of frequency identification or engineering and troubleshooting are performed at fixed scan height indoor semi-anechoic facilities or free space facilities. Free Space facilities, in particular, have been put forth as a possible future alternative standard to open area test site (OATS) for certification measurements. An analytical and experimental comparison of the relative merits of these different types of facilities is presented.