Apertures coupling for electrical field calculation in Ariane 5 launcher cavities: Experimental characterization of apertures´ effective coupling cross section in oversized complex cavities

The present paper reports the main results of a study which aimed at characterizing the effective coupling cross section of apertures open onto oversized complex cavities. This study has been performed in the frame of a CNES (French National Center for Space Studies) contract aiming at assessing the Power Balance Method for calculation of the electrical field induced by a satellite telemetry transmission under the launcher´s fairing, during flight. Two cases have been considered. The first case corresponding to an aperture between the outside and one of the launcher´s cavities has been studied in an anechoic chamber; the second case corresponding to an aperture between two of the launcher´s cavities has been studied in a stirring mode reverberation chamber. For each case, the experimental results have been compared to theoretical formulas.