Average attenuation supplemented by maximum-to-average ratio in reverberation chamber measurement of transmission functions

The shielding effectiveness of complex structures with apertures in an electromagnetic environment often can not be calculated analytically or be simulated in detail with reasonable effort. One possibility to gain information on the attenuation of a real structure is the Power Balance Method (PWB)[1]. The attenuation, which is determined by this way is to be considered as an average attenuation, with respect to the fact that it employs the statistical evaluation of the field quantities in a reverberation environment. To focus on some details regarding the attenuation determined by this technique, a conductor current is observed twice inside a Reverberation Chamber (RC). Once, when the conductor is placed above a Groundplane (GP) and once, when the conductor is mounted inside a fuselage model with apertures. The conductor currents are obtained from scattering parameter data, which are measured by a Vector Network Analyzer (VNA). The comparison of both cases shows an excpected attenuation. Different maximum-to-average ratios for both conductor currents are observed and discussed.