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Important features of Transverse Electric Waves |
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For a given value of ' ' the variation of the fields in the  - direction is fixed irrespective of the frequency. |
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For example, for  , the fields have one half cycle variation in the - direction, for  the fields have |
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one full cycle variation, i.e, two half cycle variation in the - direction and so on. |
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The field variation for and is shown in the following figure |
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For , the electric field is maximum half way between the two planes and zero at the two planes. |
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The field pattern is therefore unique for a given value of '' |
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Since '' is an integer there is no gradual change between two field patterns. The field pattern exist as their |
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individual identities. |
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These unique field patterns are called 'MODAL FIELD PATTERNS' and the propagation of electro magnetic energy |
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in these patterns is refered to as the 'MODAL PROPAGATION' |
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The modal propagation is the interinsic characteristic of any bound structure like wave guide's . |
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The electro magnetic fields inside the wave guide exist only in the form of the Modal Field patterns. |
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------------- (6.5) |
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------------- (6.6) |
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It can be seen from field expressions 6.5 and 6.6 that for  the electric field vanishes and consequently |
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the time varying magnetic field also cannot exist. It therefore suggest that the field pattern corresponding |
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to cannot exist inside a parallel plane wave guide. |
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It is clear from the field expressions that the wave travels in the  direction and the electric field which is |
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 - oriented is always transverse to the direction of wave propagation. This mode is therefore called the |
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'TRANSVERSE ELECTRIC or TE MODE' . The '' is put as the suffix to indicate the order of the mode. |
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The  mode is therefore a mode with fields having '' half cycle variations in the transverse plane. |
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Since is not possible we only have modes
 ,
 ,
 ,....... |
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