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.
Fundamental models for near-field shielding
Models for fundamental shielded enclosures are developed. The models clearly show the dependence of the emissions from the shielded enclosure on the nature of the basic source of emissions within the enclosure. The models serve to clarify aspects of Schelkunoffpsilas approach to shielding analysis which are often questioned.
An accurate method of computing far-field antenna pattern from near-field measurements
An accurate method is presented for computing far fields from near-field antenna measurements. The method has the advantage of being simple and easy to implement, and in addition it is amenable to a variety of antenna measurement configurations. Data from planar, cylindrical, or spherical near-field measurements, or from other simpler orientations such as in a horizontal plane, require the solution of a large system of linear equations; this may be accomplished efficiently using the conjugate gradient method. Numerical results are presented for the case of an x-directed Hertzian dipole.<<ETX>>