Transmission-Based Imaging of an Electrically Small Aperture in a Shielded System

The possibility of imaging the position and nature of apertures in a metallic shielding is discussed. Synthetic images are obtained from signals induced at the interior of the shielding by a set of plane waves impinging on it along different directions of arrival. The proposed technique works analogously to inverse synthetic aperture radar imaging, but is based on signals related to transmitted rather than scattered waves. A theoretical analysis of the features of the images associated to electric and magnetic coupling is presented.