Simulation Study Of The Anomalous Propagation Of The Tunnel Effect Of Electromagnetic Waves

Tunneling effect is a important problem of quantum mechanics,and tunneling process is the basic process of quantum mechanics. But so far, there has no satisfying answer for that how much time particle need to traverse tunnel of barrier. There have many sameness between quantum mechanics and electromagnetics,such as the equivalent of tunneling effect and cutoff waveguide. So that,to perfect the cognition of tunneling process,research of the propagation of electromagnetic wave in cutoff waveguide is necessary. In this paper,first,the velocity of wave in free space and waveguide have been studied. It is been proved that the tunneling effect and propagation of TE wave in cutoff waveguide are equivalent. And the tunneling effect of wave packet is analyzed concretely.In this paper, the behavior of propagation of TE wave through the different structure waveguides with piecewise different dielectric constants is been simulated by MAGIC program. The plots of electromagnetic field,energy,Ponyting vector and their spectrums are been obtained. And,the group velocity and energy velocity of wave packet through barrier have been calculated. Then the graph of the changes of group and energy velocity with the length of cutoff region and the main frequency of the wave packet is received. From the graph, when Gauss wave is input, it could been found that average group velocity increases linearly with the length of cutoff region when the length is less than one value; and when the length is greater than the value, it minishs as index. When the length is in one range, average group velocity is greater than the light speed in vacuum c. Moreover, it descends linearity with the main frequency of wave packet. From the graph of electric field spectrums, it shows that the spectrums move up clearly. When the length of cutoff region is so long or the main frequency is so high to approach the cutoff frequency, the main frequency of wave packet is so high to exceed the cutoff frequency. It illuminates that the main part which transit cutoff region is high-frequency ponderance. But energy velocity is smaller than the light speed in vacuum c all long. When cos-AM signal wave is input, it shows that output waves distort badly. It is no possible to resume the output wave, and it is no meaning to calculate the velocity. As same as dissertation above, the main part which transit cutoff region is high-frequency ponderance, and low-frequency ponderance is attenuated badly.