Comparison of anechoic and reverberation chamber coupling data as a function of directivity pattern

This paper compares coupling data from an external field to an internal probe for anechoic and reverberation chamber tests as a function of the directivity pattern of a test article and the test conditions for both chambers. The investigation uses an extensive measurement data base from both anechoic and reverberation chambers. In an ideal anechoic chamber test, the test article is illuminated by a plane wave of a specified field strength with both horizontal and vertical polarizations at a sufficiently large number of aspect angles. In a typical standards compliance test the number of aspect angles is limited. In an ideal reverberation chamber test with a large number of independent samples (tuner positions), the test article is illuminated by a statistically isotropic field where the maximum field strength is a random variable with a predictable expected value and uncertainty. In a typical standards compliance test the number of tuner positions is limited implying the test environment only approximates ideal conditions and the expected value of the maximum field has a larger uncertainty. The focus of the this investigation was to compare a test article response and its uncertainty as measured in typical anechoic and reverberation chamber tests.