Field measurements within a reverberation chamber based on the perturbation theory

The purpose of this paper is to describe and to measure the electric field distribution inside a reverberation chamber (RC) by using the perturbation theory. We firstly show how the measurement antenna classically employed disturbs the field distribution and induces measurement errors. The proposed technique is then presented for a spherical metallic or dielectric perturbating object. While the use of a metallic sphere leads to a resonant frequency variation function of the electric and magnetic field amplitude, it is possible with a dielectric sphere to extract the electric field distribution within the cavity. Simulations and measurements results match with theory.