l、线性Linearity 若f(t)→F(j0),f(0)→F(j0), 且设a1,a2为常数，则有 af(t)+a2f(t)>af(j@)+a2(j@) 若则 FT f(t)]=F(@) m三ao立a5o 33 1、线性 Linearity 若 则  ( ) () i Fi FT f t            n i i i n i FT ai f i t a F 1 1 ( ) () 若 ( ) ( ), ( ) ( ), f 1 t  F1 j f 2 t  F2 j 且设a1 , a2为常数，则有 ( ) ( ) ( ) ( ) a1 f 1 t  a2 f 2 t  a1 f 1 j  a2 f 2 j