• 2022-05-25
    求图 3-17 所示信号的频谱函数。[br][/br][img=278x235]17a33469f9c0a5d.png[/img]
  • 解 解法一 [tex=4.429x1.429]7wP88YFRrLQSGJdxsSsC01fJn9C2rOzcVU57NcSaIz+x1BtfGG75MIqYBtu4AjEX[/tex] 的波形如图 3-18( a ),( b ) 所示。利用傅里叶变换的时域微积分性质求解。[img=531x293]17a3348a7978562.png[/img][tex=22.857x5.214]a0s3MH7cLIdmiBRR0YN06+rQT8dv1wqRetfw3BtOjz7A94hEQYXOHbMSv9ocV+CMGXMQBipcAqGgir/6GigzG4A9XU0qftftOAu/e9m84qALHTHfYkOB+dAQfMQrIaGn9tle9iM/b1DuLrIZtjn5Uq3CtsKXcPFzF4+zMSynQUN2llh1/Q7AuGCk+GqggDDaOVxaaZjzQGLt5QKmGPKGB/S3IXVEntJycZepzJGZVRTDYOGfVJXyPFxs094D6C1jbNIZfvi/xfJqW/1gmlC97BIWj6qQxW9WwVQZLmNd+RUDAnI4NTAOYCIvWC+u4W4Z/uBSLJVxoATl6pz4+uXMXMF+TQ7njlQDXpwjw7VicKYiJnqB8zZOdKWHrXSBn8GZ9X8UdDpNw5APzXFYoMRtrnoNXKn5cRx4/Uaf+kinnMroaTA0zqdND+Zij8qJL1Pl[/tex]显然 [tex=4.571x1.429]lbT1PPZWcSbNEv45cVpXhPd4akqzyNfzc+AmK4LkioI=[/tex], 因此[p=align:center][tex=29.571x2.786]GAfTgVt2kx+QJln4jWKy8or8AqhmdfK4O/0SCtG9aAobdLiYzpk4oj+iRtqfkU+NNGVgbLiOAD3qmyaLhNQIl3WuNH9QOO7fdRshRbRCSf8mgvpJuAFlm0AMZh7SPA1t+oCPnECQKHbEYjYxWp+xIJF0ylEcJcT9qVSAdkz062Ecjbi8pIl2NulQCytEASifzBZW+yNOPJLt9y8pq5+SM9rMrYfQ99amIT2WqGDLH6Qy8qNw4SRTGDWVzzjKPKlxO05tqyeBWLyilZ8Iewd1vQ==[/tex]解法二 用叠加性质求解。[p=align:center][tex=12.714x2.786]kZz+MqmLZhriE+aTlKaP3Y3UFCU1/R4IIa2fwMOsR027qhsSHzLzUAnKEzigD9BWVo1jPkBAVhYcooWY0sW+YqCqeEuXWs99m3oGK7tA+ec=[/tex]因为        [tex=23.643x2.786]NPrWLSyU0971TiifT6ehXc/qzS0uJF7HKH+U4RFUreON8jAPS0yI08pmpQFNAjGz8IhscD2+5ev+mn3gQB5jUTS+3sQZ1qg4EVu3EEr9Ie6Xf1a6aSd+DKaK8RATD2e4chUOMNhUv3irPqByAjwoNs62JUk66QXZZCqM/hPJw5cRcfhcrjBa5PG5cpJ1FUIIwWKBxi9mCS+lmgIpdnwE7pvFvAwIm9W1N94sSWCMICepwxTLWbqCUZ3YKY+72Z3c[/tex]所以                    [tex=12.714x2.214]WZfveWkiWEEOr3rzmdE+NBDFGv32ZivmURKcYLpIFAcIoY2FO6BpjA2LPoqzh6FIKx4Bl9xuqnpoQP/+KbwrNXBDszmaMZlARkrt4toZI1phVHbNemBNfo/+3qGsGZEW[/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

      试用时域微积分性质,求图所示信号的频谱。[img=208x145]17aed91a18c6881.png[/img]