求图所示信号[tex=1.643x1.357]QEos0FZVoxidwAY2Qi/JJQ==[/tex]的频谱函数[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]。[img=280x214]17a484dec4d23f7.png[/img]
求图所示信号[tex=1.643x1.357]QEos0FZVoxidwAY2Qi/JJQ==[/tex]的频谱函数[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]。[img=280x214]17a484dec4d23f7.png[/img]
[tex=1.643x1.357]QEos0FZVoxidwAY2Qi/JJQ==[/tex]的频谱[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]如图所示。利用卷积性质粗略画出[tex=5.429x1.286]sniVC9+Hi3ttzY5j2x49GWeJWY+WYcTHtSdulbGWN1xdm2O3qUVxtR9s6n3pz7sD[/tex]的频谱（注明频谱的边界频率）。[img=583x252]17a4882e08ecb1c.png[/img]
[tex=1.643x1.357]QEos0FZVoxidwAY2Qi/JJQ==[/tex]的频谱[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]如图所示。利用卷积性质粗略画出[tex=5.429x1.286]sniVC9+Hi3ttzY5j2x49GWeJWY+WYcTHtSdulbGWN1xdm2O3qUVxtR9s6n3pz7sD[/tex]的频谱（注明频谱的边界频率）。[img=583x252]17a4882e08ecb1c.png[/img]
若[tex=5.929x1.357]Fz8bbkli6D2vaDrK4tDVqu5vDYU/CUlk1lerKQLPAwc=[/tex]，[tex=1.643x1.357]nbrmolTBCxea6n6kpOel7g==[/tex]是周期信号，基波频率为[tex=1.071x1.286]ztfUi/o6QYSUAx3sUs5vwg==[/tex]。令[tex=6.071x1.357]CstTdnSmDZJmIJwCRpsS3cfSTgJftOdhvmm28LsDKks=[/tex]，若[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]的图形如图所示，当[tex=9.929x2.786]4Pid5P8x0MkGkeAgWhdzU2pSf58Dki18iomj86bcAuKkkvwWo7+JyUSlsToZyFRW7hkg52Y89pn4rda6RF6c4g==[/tex]时，求相乘信号的傅里叶变换表达式[tex=6.643x1.357]ZWTTA7CktKgpGc5IY/j/dZRyw1wdxkP71uh0NytuvXoUiW/4M7WZdJc80lb6E2vS[/tex]。[img=268x187]17a4cc3c36dc7bc.png[/img]
若[tex=5.929x1.357]Fz8bbkli6D2vaDrK4tDVqu5vDYU/CUlk1lerKQLPAwc=[/tex]，[tex=1.643x1.357]nbrmolTBCxea6n6kpOel7g==[/tex]是周期信号，基波频率为[tex=1.071x1.286]ztfUi/o6QYSUAx3sUs5vwg==[/tex]。令[tex=6.071x1.357]CstTdnSmDZJmIJwCRpsS3cfSTgJftOdhvmm28LsDKks=[/tex]，若[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]的图形如图所示，当[tex=9.929x2.786]4Pid5P8x0MkGkeAgWhdzU2pSf58Dki18iomj86bcAuKkkvwWo7+JyUSlsToZyFRW7hkg52Y89pn4rda6RF6c4g==[/tex]时，求相乘信号的傅里叶变换表达式[tex=6.643x1.357]ZWTTA7CktKgpGc5IY/j/dZRyw1wdxkP71uh0NytuvXoUiW/4M7WZdJc80lb6E2vS[/tex]。[img=268x187]17a4cc3c36dc7bc.png[/img]
若[tex=5.929x1.357]Fz8bbkli6D2vaDrK4tDVqu5vDYU/CUlk1lerKQLPAwc=[/tex]，[tex=1.643x1.357]nbrmolTBCxea6n6kpOel7g==[/tex]是周期信号，基波频率为[tex=1.071x1.286]ztfUi/o6QYSUAx3sUs5vwg==[/tex]。令[tex=6.071x1.357]CstTdnSmDZJmIJwCRpsS3cfSTgJftOdhvmm28LsDKks=[/tex]，若[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]的图形如图所示，当[tex=9.429x2.786]4Pid5P8x0MkGkeAgWhdzU2pSf58Dki18iomj86bcAuJEqvbzJDpdWqjvIBHBHgLRfbrSKluZNI/GBmy8/K475w==[/tex]时，求相乘信号的傅里叶变换表达式[tex=6.643x1.357]ZWTTA7CktKgpGc5IY/j/dZRyw1wdxkP71uh0NytuvXoUiW/4M7WZdJc80lb6E2vS[/tex]。[img=268x187]17a4cc3c36dc7bc.png[/img]
若[tex=5.929x1.357]Fz8bbkli6D2vaDrK4tDVqu5vDYU/CUlk1lerKQLPAwc=[/tex]，[tex=1.643x1.357]nbrmolTBCxea6n6kpOel7g==[/tex]是周期信号，基波频率为[tex=1.071x1.286]ztfUi/o6QYSUAx3sUs5vwg==[/tex]。令[tex=6.071x1.357]CstTdnSmDZJmIJwCRpsS3cfSTgJftOdhvmm28LsDKks=[/tex]，若[tex=2.071x1.357]IVBnoG/ZLtJA1HKOoFX6Lw==[/tex]的图形如图所示，当[tex=9.429x2.786]4Pid5P8x0MkGkeAgWhdzU2pSf58Dki18iomj86bcAuJEqvbzJDpdWqjvIBHBHgLRfbrSKluZNI/GBmy8/K475w==[/tex]时，求相乘信号的傅里叶变换表达式[tex=6.643x1.357]ZWTTA7CktKgpGc5IY/j/dZRyw1wdxkP71uh0NytuvXoUiW/4M7WZdJc80lb6E2vS[/tex]。[img=268x187]17a4cc3c36dc7bc.png[/img]