单项选择题
已知连续实信号的频谱为,则信号的频谱为()
A.B.C.D.
A.100HzB.150HzC.200HzD.400Hz
A.j4Sa(ω)sinωB.j2Sa(ω)sin2ωC.j4Sa(ω)sin2ωD.4Sa(ω)cos2ω