The Statistic Characteristic Research Of Electromagnetic Effect Physical Quantity In Chaotic Cavity

In the field of high-power microwave (HPM) effects and electromagnetic compatibility (EMC) study, researchers are much interested in the item of short-pulse coupling into the large complicated enclosures. In this dissertation, the random coupling model (RCM) was analyzed based on random matrix, statistical electromagnetism, plane-wave hypothesis, quantum mechanics and electrodynamics theory. The RCM was summarized by combination of the theory and the experiment research.However, as an emerging research area, the applications of RCM in HPM effect and the EMC research have just started. There remain many pressing problems to be solved. Based on systematic analysis in the wave chaotic cavity, applicability of RCM was discussed in practical conditions.The RCM is a stochastic model which makes use of the random plane wave hypothesis and random matrix theory to formulate a statistical model for the impedance, admittance and scattering properties of time reversal symmetry (TRS) and broken time reversal symmetry (BTRS) wave-chaotic systems. Moreover, these fluctuations are expected to be universal in their statistical description, which depends only upon the value of a single dimensionless cavity loss-parameter. The port-coupling characteristics were accurately quantified by the "radiation impedance". The cavity scattering is recovered by combination of cavity loss and "radiation scattering".Firstly, a brief review of the status of HPM effect research was presented in this dissertation. Then the characteristics, the scope of usage and limitations of the existing method of HPM effects were analyzed and compared. Focusing on the influence of the uncertainty of the target and the random process, the RCM was introduced. Secondly, theoretical basis of RCM were described and analyzed. In order to prove the reliability and practicality of RCM, simulation and experimental investigation using the computer box cavity as a microwave chaotic cavity were carried out. The applications of RCM in the computer box with different states were discussed. The main obtained conclusions are as follows:Some results were found through simulation, experimental research and RCM calculation. While statistical analysis with effect results from a series of similar object is carried out, experimental study on traditional methods will require a large number of experimental samples, and numerical simulations of similar targets are more time-consuming. However analysing the system with RCM can give a convenient statistical result of induced voltages simply with a small number of system parameters.The numerical simulation and experimental study on the wave chaotic cavity reveals that the scattering behavior within computer box is the chaotic scattering and agrees well between the simulations and experimental results for the normalized impedance and the RMT predictions. The statistical properties of normalized impedance and admittance eigenvalue real part and imaginary part agree each other well, and don't change with the reference surface movement and depend only upon the cavity losses. With the increase of cavity loss, insertion phase shift distribution is becoming more and more homogeneous. The radiation impedance of the coupling port combined with the numerically generated normalized impedance z from random matrix theory can obtain an estimate of the non-universal system-specific scattering coefficient.Practicability of RCM has validated by measuring the magnitudes of induced voltages at key points within computer box. It shows that the two results are basically the same trend. The experimental scattering radiation measurement process directly affects the final results.In statistical electromagnetism, electromagnetic compatibility and HPM effects research field, the RCM has important practical value. However, study on RCM at this stage is still at a preliminary stage. In order to make it a general purpose research tool as soon as possible, it calls for more in-depth theoretical and experimental research. New methods and ideals should be exploited by combining the quantum mechanics with statistical electromagnetism in the field of HPM effects.