RCS measurement accuracy in the U/VHF range: Measurement of the electromagnetic field decrease rate in an indoor anechoic chamber

A diagnosis system has been implemented to determine the variation of the electromagnetic field transmitted by a phased array antenna along the transverse and longitudinal axes of a RCS facility. It exploits the reflection coefficient of a sphere moving along the axis. The results obtained in the anechoic chamber CAMELIA of the CEA have shown good agreement with the expected results: the field varies as a 1/r² law in the longitudinal direction, and is related to the antenna measurement radiation pattern in the transverse direction.