[工學(xué)]電磁場(chǎng)與電磁波第19講無(wú)耗平面波導(dǎo)電平面波-資料下載頁(yè)
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【正文】 m the origin從原點(diǎn)出發(fā)的徑向矢量 ? ? ? ?x x y y z z nk a k a k a k k a? ? ? ?then ? ? ?x y zR a x a y a z? ? ??00( ) = ( V /m )njk a Rjk RE R E e E e ?????22 0 0E k E? ? ?30 where an is a unit vector in the direction of propagation. 沿傳播方向的單位矢量 ?00( ) = ( V /m )njk a Rjk RE R E e E e ?????? ? ? z y x d an P0 E0 ? P(x, y, z) R The geometrical relations of an, and R are illustrated in Figure, from which we see that is the equation of a plane normal to an , the direction of propagation. an ?R = Constant is a plane of constant phase and uniform amplitude for the ? L e ng th O P ( a c on sta nt)naR ??In a chargefree region, ??E = 0. As a result, 0000( ) = 0( ) + ( ) = 0( ) = 0jk Rjk R jk Rjk REeE e E eEe??? ? ? ?????? ? ? ? ?? ? ?31 then 0()()0( ) =0? ? ?( ) = ( )? ? ? ?()?( ) =0x y zx y zjk Rj k x k y k zjk Rx y zj k x k y k z jk Rx x y y z z njk RnEee a a a ex y zj a k a k a k e j k a ej k E a e??? ? ???? ? ? ??????? ? ?? ? ?? ? ?? ? ? ? ? ?? ? ?Which requires Thus the planewave solution implies that E0 is transverse to the direction of propagation. E0垂直與傳播方向 0 ? =0nEa?The magic field associated with E(R) may be obtained as 相伴的磁場(chǎng) 11 ?( ) ( ) o r ( ) ( ) ( A /m ) ,nH R E R H R a E Rj ? ? ?? ? ? ? ? ?32 Where ? is the intrinsic impedance (wave impedance) of the 質(zhì)的本征阻抗 /波阻抗 E H an ( )k? ? ???? ? ?1 ?( ) ( ) ( A /m ) ,nH R a E R????01 ?( ) ( ) ( A /m ) .nj k a RnH R a E e?????It is now clear that a uniform plane wave propagting in an arbitrary direction, an, is a TEM wave with E?H and that both E and H are normal to an. 沿任意方向傳播的均勻平面波是橫電磁 (TEM)波 The electric field associated with H(R) may be obtained as 1 ?( ) ( ) o r ( V /m )nE R H R E a Hj ???? ? ? ? ? ?33 Summary 2202 0xxdE kEdz ??0000( ) ( ) ( ) jk z jk zx x xE z E z E z E e E e?? ? ? ?? ? ? ?00 0 0( , ) Re c o s( ) ( V /m )jk z jtxE z t E e e E t k z? ??? ? ???? ? ???0 00pdzucd t k??? ? ?? ? ? ?002 2 2 ( r a d /m )fkc c Tc? ? ? ??? ? ? ?0 02 ( m )k?? ?0 0 0 ( r a d /m )k c?? ? ???1. Plane Waves in Lossless Media 0E j H??? ? ? ? 0 0 0000 001 2 0 3 7 7 ( )k? ? ? ? ??? ?? ? ?? ? ? ? ? ?34 ?00( ) = ( V /m )njk a Rjk RE R E e E e ?????11 ?( ) ( ) o r ( ) ( ) ( A /m ) ,nH R E R H R a E Rj ? ? ?? ? ? ? ? ?1 ?( ) ( ) o r ( ) ( ) ( V /m )nE R H R E R a H Rj ???? ? ? ? ? ?2 2 2 2 2x y zk k k k? ? ?? ? ? ?? ? ? ?x x y y z z nk a k a k a k k a? ? ? ?? ? ?x y zR a x a y a z? ? ? transverse electromagic waves 35 homework Thank you! Byebye! 答疑安排 時(shí)間：周四 下午 15： 00~18： 00 地點(diǎn)： 1301， 1311 P. 84。 85。
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