Research on imaging detection of RF leakage on the surface of spacecraft
The determination and locating of leakage point is very important to shielding effect evaluation and solving EMC problem of spacecraft. A RF leakage detection method by near field scanning imaging is presented. The electromagnetic field distribution on the surface of spacecraft can be deduced from one on the plane at some distance to the surface of spacecraft with the convolution relation between electromagnetic field distributions on two parallel planes. The imaging of RF leakage point can be obtained by the method. The effect to imaging of measurement parameters is evaluated by simulation.
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.
Susceptibility Mapping
The concept of susceptibility mapping is introduced. A susceptibility map is created by scanning a signal source (loop antenna) over a circuit board, and at each point raising the signal level until failure occurs. Maps obtained with CW EM1 reveal design problems such as tight circuit timing or small static noise margins. They also reveal manufacturing problems, such as bad contacts and faulty chips. This leads to the concept of electromagnetic stress testing. Maps obtained with transient EM1 require tight synchronization for repeatability and are useful in studying specific software-dependent failures.