已知連續(xù)實(shí)信號的頻譜為,則信號的頻譜為()
A.B.C.D.
A.100HzB.150HzC.200HzD.400Hz
如圖所示信號x(t)的頻譜X(jω)等于()
A.j4Sa(ω)sinωB.j2Sa(ω)sin2ωC.j4Sa(ω)sin2ωD.4Sa(ω)cos2ω