Study Of Different Polarized Wave Coupling Into Cavity With Printed Circuit Board

The coupling effects between the electromagnetic pulse and cavity are studied in this dissertation. Since these problems belong to the transient electromagnetic field, the finite-difference time-domain (FDTD) method is applied to simulate the computer case. The results show the coupling process between the electromagnetic wave and the cavity. Based on these results, the corresponding Frequency-Domain waves are obtained. It will be useful to theory and project applications of electromagnetic wave coupling into shielding cabinet.At first, the approaches of electromagnetic interference and the applications of circular polarized wave are introduced. Through the analysis of the status at home and abroad, the advanced and exploratory properties of this paper are showed.As the foundation of this dissertation, the FDTD method is introduced simply at first. Then the coupling characteristics of a cavity with slots are studied by applying this method. The results compared with CST's show that the method we used is feasible.Because the coupling effect between the electromagnetic pulse and computer is of strategetic significance, four different pulses coupling into computer box are studied. According to the Frequency-Domain data, we obtained the coupling functions which reflect the coupling characteristics.On the other hand, the couplings characteristics of a cavity are compared when the incident wave is circular polarized or linear polarized. The influences brought by Microstrip Circuit Board into the coupling are studied. Then the computer case's shielding effectiveness is analyzed when circular polarized wave and linear polarized wave used as incident wave.Besides, the coupling effect between the electromagnetic wave and the cavity with a cable is researched. The influences of the coupling characteristics caused by the wave's incident angle and the cable's parameter are also analyzed. And the results we obtained are useful to the fence and attacks of the electromagnetic interference.Finally, in this dissertation, the study of cavity's coupling effect is summarized, and the development of the research in this field is also prospected.