第17讲 平面电磁波(I)

1、主讲：史琰00EHtHEtHE ()()HHtt 2()EEE 2220EEt222222221010EEvtHHvt1/00EHtHEtHE ()()EEtt2()HHH 2220HHt( , )0( , )( , )( , )0yxzE z tEz tEz tE z txyz( , )( )zEz tc t0,0HHxy0,0EExy( , )0( , )( , )( , )0yxzH z tHz tHz tHz txyz( , )( )zHz tc t( , )( , )xxyyEa Ez ta Ez t( , )( , )xxyyHa Hz ta Hz t22222( , )( , )

2、10 xxEz tEz tzt12( , )()()xEz tf ztfzt)(),(vtzftzEx( , )00 xyzxaaaBExyztEz t xyEHazt 222210yyHHzt)(),(vtzgtzHy( , )( , )()( , )( , )()xxxyyyE z ta Ez ta f zvtH z ta Hz ta g zvt( )00 xyzxyxaaaEjjjHEaxyzzEzHjEk 0)()(222zEkdzzEdxxjkzjkzxeEeEzE00)(000000 ()()1() ()jkzjkzyjkzjkzyjkzjkzyjHajk E ejk E eaE

3、eE eaH eH ekHEHE00003771200000jkzxxxEa Ea E e00jkzjkzxyyyEHa Haea H e()000()00000( , )Recos()( , )Recos()cos()jt kzxxmjt kzmyyymE z ta E ea EtkzEEH z taeatkza Htkz0000( , )cos()( , )cos()xmymE z ta EtkzH z ta Htkz0.tkzconst（常数）1pdzdtkk20000( , )cos()( , )cos()xmymE z ta EtkzH z ta Htkz80013 10pm s 2

4、k21Tfpf2T*200011*222jkzjkzmxyzEESEHa E eaea20Re 2mavzESSa22200222002200111( )cos ()22211( )( )cos ()221cos ()2/( )emmmmew tD EEEtkzwtHtHtkzEtkzw t 22,0,02,011,4412av emav mmavav eav mmwEwHwwwEaveavSvw22001/22mmezezzpEEva vaav83 10em s 0jkzxEa E e00000()()jkzjkzjkzjkzjkzzzjjHE eeEeEjjejkaEjkaE e（）（）z

5、kHaEHjEjkzeEE00000()()0jkzjkzjkzjkzzE eeEeEjk aE e 0zaE0 EEakHz0Eaz0HazzjkeEE0EakHz0Eaz0Hazcoscoscosxyzzxyzzra xa ya zaaaaazr a zazjkeEE0EakHz(coscoscos )zxyzxyzkzkaraaaak rk rk xk yk zkrk jeEE0EaEakHkk10Eakrk jeHH0HaHakEkk0Hak0jk rEE e0jk rHH e333/jkzjjkzxyEaeaeV m8813 1010/9rrcm s pv 相速相速n(2)rad/m

6、k 2231(43)(/)jkzjjkzyxjHEaeaeA m88( )Re4cos(2102)3cos 2102(/)3j txyE tEeatzatzV m88( )Re31cos(2102)cos 2102(/)40310j txyH tHeatzatzV m 1pvmf波长波长2/prad mv k 波数波数波阻抗波阻抗 40 91120 000rrrr*3321131432240105/16j kzj kzjkzjkzxyxyzSEHaeaeaeaeaW m 25Re /16avzSSaW m516avSavPSdSW00HEjEEjHHE cHjjEjE jjc1222200EE

7、HH0j zxEa E ej0j zxEa E e0( , )cos()azxmE z ta E etz00jmEE ezjzxeeEaE0jc22jja22)(jaja22222222j2211211200j zazj zyyccEEjHEaeaeejccejj21140arctan211412c0( , )cos()|azmycEH z taetzjzjzcyzjzcyzjcyeeeEaeeEaeEaH0000( , )cos()azxmE z ta E etz0( , )cos()|azmycEH z taetz12212111pdzvdt2pf2201( , )( , )( , )coscos(222)2azmzcES z tE z tH z taetz221cos2azmavzcESae221*2azjmzcESEHaee222222,21111444azazmav mm