EMI noise source discrimination using cross domain analyzer and analog RoF link with mobile robot
In this paper, we propose a new method for electromagnetic interference (EMI) noise analysis using an analog radio-over-fiber (RoF) link, cross domain analyzer, and mobile robot. With this new method, both the phase distribution and amplitude distribution of an electric field radiated by an EMI noise source can be measured. From the measured and simulated results obtained using the method of moments technique, we show that we can differentiate between noise sources in different positions using the phase distribution measured on a measurement circle.
The noise source modulation technique for the determination of electromagnetic noise path
The noise source modulation technique (NSMT) is proposed to determine the electromagnetic noise path when an EMC problem appears. The basic idea behind the NSMT is to apply a known time variation (modulation) to one of the possible noise paths and to observe its effect at the noise victim location. Different modulations can be applied to different noise paths simultaneously. Based on the type and amount of noise modulation at the victim location, the noise path can be determined.
Thermally Induced Dynamics of Satellite Solar Panels
Thermally induced structural motions are known to affect the attitude dynamics of low Earth orbiting satellites during eclipse transitions. Motions of e exible appendages such as solar panels lead to rigid body rotations of the entire satellite because the total angular momentum of the system is conserved. These potentially large attitude disturbances may violate pointing accuracy and jitter requirements. One type of thermally induced dynamics exhibited by solar panels is thermal snap. The Upper Atmosphere Research Satellite is a prominent example of a satellite that experiences thermal snap disturbances during eclipse transitions. This paper describes recent studies of thermally induced dynamicsof solarpanels, including an analysisofsatelliteattitudedynamics resulting from thermally induced structural motions and a laboratory investigation of the thermal-structural performance of a satellite solar panel. Analytical and experimental results demonstrate thermal bending deformations with acceleration transients that have characteristic thermal snap disturbance histories in response to rapid changes in heating. The studies show that solar panel thermal snap disturbances are caused by through-the-thickness temperature differences that vary at a nonconstant rate. Finite element analysis correctly predicts the thermal snap phenomenon observed in the solar panel experiments.