利用三种方法求题4.20图所示信号的频谱。[br][/br][img=270x184]17a476a49cd15dc.png[/img]
解:方法一:利用定义[br][/br][tex=11.5x3.929]jV/hSjz8JTuP1b8O5nNVkOTa+kPV65AGbb+mLW0xo2qve3rPXS4bMbi881vGPdgSnMQlpi8m7lx/KLiNZbWSC6xIaxpZVXcw4o06lZ3F2yxDQfs44CJ09PZOo/JBsgUUnHFtCMY96ZQ8rFCJ7GswlA==[/tex][br][/br][tex=33.143x8.5]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[/tex][br][/br]方法二:利用时域微分性质。[br][/br][tex=24.714x8.5]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[/tex][br][/br]方法三:利用频域微分性质。[br][/br][tex=28.5x9.786]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[/tex]
举一反三
- 求图3-19所示信号的频谱函数。[br][/br][img=317x262]17a3349ef6be932.png[/img]
- 求图3-21所示信号的频谱函数。[br][/br][img=253x200]17a335804bc7223.png[/img]
- 求图 3-17 所示信号的频谱函数。[br][/br][img=278x235]17a33469f9c0a5d.png[/img]
- 求图3-32所示周期性冲激信号的频谱函数。[br][/br][img=329x248]17a33c48eb791d9.png[/img]
- 图 10-12( a )所示系统，其中 [tex=1.714x1.357]AphGGQbUXHAeuIs1fgWQNA==[/tex] 的频谱如图 10-12( b )所示,[tex=3.0x1.357]sewg5QwPKOn7w7wgfdPAVuwqkrCzSKPDGly088lsz4g=[/tex]的频谱如图 10-12( c )所示。[br][/br][img=681x428]17a464f8d7042bc.png[/img][br][/br]求信号 [tex=1.714x1.357]AphGGQbUXHAeuIs1fgWQNA==[/tex]
内容
- 0
求图5-7所示信号的拉普拉斯变换。[br][/br][img=369x221]17a3448107ecc2f.png[/img]
- 1
求图5-32所示各信号的拉普拉斯变换。[img=752x311]17a37bfad3d094f.png[/img][br][/br]
- 2
[img=239x211]17a5b76544ccb31.png[/img]求图所示三角形调幅信号的频谱。
- 3
求图所示三角调幅信号的频谱。[img=366x367]17a4c95f0f8d94e.png[/img]
- 4
试求题2-28图所示电路中的支路电流i。[br][/br][img=371x341]17d23ed7ee632aa.png[/img]