Photonic-assisted diagnosis of electromagnetic coupling into a generic object

A photonic-assisted probing system to diagnose the electromagnetic influences of an electronic subsystem against intense electronic threat is presented. The shielding effectiveness of a generic missile and the coupled fields into the missile cavity were investigated by a fiber-coupled electro-optic field probe with its associated photonic system. To characterize the absolute field strength in the cavity, the probe was calibrated with a standard gain horn antenna at the R band by generating known fields toward the generic object. The fields coupled into the metallic cavity can be resonantly built up at multiple frequencies over a power range of 32 dB. The measured resonance characteristics of the hollow generic cavity showed good agreement with the computational data. This indicates that the electromagnetic susceptibility of an electronic sub-system with an enclosed metallic cavity can be readily exploited using the photonic-assisted system presented here. The strength and spectra of the resonant fields that passed through the aperture of the generic cavity at various internal locations are presented. This measurement system is quite effective at measuring actual fields without the need for a probe compensation procedure. Thus, it can be utilized for diagnosing the shielding of a generic system against intentional electromagnetic threats when the interiors of the generic objects become highly sophisticated. (paper)