电磁场与电磁波第三版答案第七章.pdf

7-1 r r 2 r () v I d lk 3 sinθ j e θ 4πωε kr r 2 v I d lk 3 sinθ 1 e θ 2 4πωε (kr) 1 λ r 0.159λ k 2π 7-2 100 km 100 µV/m Eθ I d l E m η sinθ m 0 2λr 0 I d l P P m r r λ 40π2 0 2 ⎛ r Em ⎞ 1 P ⎜ ⋅ ⎟ r ⎝sinθ 3 ⎠ 10 10 P 1.1 W r 9 7-3 0.1λ 2 ⎛I d l ⎞2 R 80π ⎜ ⎟ r ⎜ λ ⎟ ⎝ 0 ⎠ 107 ⎛ l ⎞2 ⎛ λ ⎞2 R 80π2 ⎜d 0 ⎟ 80π2 ⎜0.1 0 ⎟ 7.8957 Ω r ⎜ λ ⎟ ⎜ λ ⎟ ⎝ 0 ⎠ ⎝ 0 ⎠ v v v v 7-4 p e p m e m z z j ω Idl −j kr p −j kr Eθ ηe sinθ − ηe sinθ 2λr 2λr