如圖所示信號(hào)f(t)的傅里葉變換為()
A.2Sa(ω)sin2 B.4Sa(ω)sin2 C.2Sa(ω)cos2 D.4Sa(ω)cos2
已知,則F(jω)所對(duì)應(yīng)的時(shí)間函數(shù)為()
A.A B.B C.C D.D
圖中f(t)是周期為T的周期信號(hào),f(t)的三角函數(shù)形式的傅里葉級(jí)數(shù)系數(shù)的特點(diǎn)是()
A.僅有正弦項(xiàng) B.既有正弦項(xiàng)和余弦項(xiàng),又有直流項(xiàng) C.既有正弦項(xiàng)又有余弦項(xiàng) D.僅有余弦項(xiàng)