Improving the correlation between OATS, RF anechoic room and GTEM radiated emissions measurements for directional radiators at frequencies between approximately 150 MHz and 10 GHz

This paper presents the results of investigations into how well the results of different measurement methods correlate at higher frequencies where near field effects can be ignored but the directivity of the radiation is important. A simplified derivation of the GTEM equations is presented to allow a clearer comparison with other methods. The effect of different open area test sites (OATS) is considered, and a universal specification suggested to define a correct result when there are differences. Existing fully anechoic room and GTEM methods are then investigated, and where necessary modifications are proposed to ensure similar results. Experimental results for a mobile phone are then presented