Research Of Random Coupling Model On Topological Network With Multiple Junctions

Because of the uncertainties of the external source, the coupling and the threshold of sensitive devise, the response of an electronic system against the external electromagnetic interference is not determinate, the induced voltage(current) on target components within the system can be described via a probability distribution function(PDF).An approach that provides a useful methodology for the analysis of complex EM interaction is the concept of EM topology(EMT) which proposes a decomposition of the geometry into subvolumes that are linked to each other in a network. The entire interaction of the network is then represented by BLT equation. The random coupling model(RCM) is a statistical model which can be used to predict the distribution of the impedance and scattering matrix of wave chaos systems from the loss parameter and average impedance. Based on the research of RCM for single wave-chaotic cavity, the RCM is used to statistically predict the induced voltage on the target component within a network of cavities by combining with the BLT equation. The work of this thesis is following:1) In predicting the impedance and scattering matrix by RCM, it's essential to generate the normalized impedance matrix z from the loss parameter by a random matrix Monte Carlo simulation. The influence of the dimension of the used random matrix on the distribution of z is analyzed, the relation between the loss parameter and the statistical properties of z is summarized for different order of z.2) Take a real computer case as an example, the RCM is used to analyze the fluctuation of the impedance and scattering matrix of the computer case and the existence of wave-chaotic scattering is proved; the difference between the normalized impedances that derived from the measured data by using the radiation impedance and the average impedance is compared and the effect of the short ray trajectories is showed; the consistency between three different methods that estimate the loss parameter is compared; given the loss parameter and average impedance, the scattering matrix is then statistically predicted by the RCM and its PDF is in good agreement with the PDF of the measured data.3) By using multiple computer cases, two-case and case network test setups have been built to verify the feasibility and accuracy of combing the EMT and RCM to analyze the short wavelength coupling issues. The scattering matrix of each case is predicted by RCM, by combining with the BLT equation, the induced voltage on the target component within the setup is computed. The PDF of the induced voltage is in good agreement with that calculated by other methods.4) The probability of EM response of electronic systems is studied by tests carried on digital cameras which are exposed to ESD electromagnetic pulse and square pulse radiation.