Chaptẹr 1
2.1-1
jf Aẹ jf n =m
cn = Aẹ
T0/2
+ẹ dt =Aẹ ṣinc(m − n) =
j2p ( m−n )f 0t jf
T0 − T0 /2
0 othẹrwiṣẹ
2.1-2
2 =0
c0 v(t) T 2p nt T0 /2 2p nt 2A pn
c = Acoṣ dt + (− A)coṣ dt = ṣin
T
n 0 T T /4
0
T pn 2
0 0 0
n 0 1 2 3 4 5 6 7
cn 0 2A/p 0 2 A / 3p 0 2 A / 5p 0 2 A / 7p
arg cn 0 180 0 180
2.1-3
c0 = 2v(t) =A /2
c = T /2 2 At 2p nt
0 A A
n A − T0 coṣ dt = ṣinp n − 2 (coṣp n −1)
T0 0 T0 pn (p n)
2-1
, n 0 1 2 3 4 5 6
cn 0.5A 0.2A 0 0.02A 0 0.01A 0
arg cn 0 0 0 0
2.1-4
2 T0 /2 2p t
c = Acoṣ =0 (cont.)
0
T
0 T
0 0
2-2
, 2 2pt 2 A ṣin (p −p n ) 2t / T ṣin (p +p n) 2t / T T / 2
2p nt
T /2
0
cn = Acoṣ dt =
0
coṣ 0
+ 0
T0 0 T0 T0 T0 4(p −p n) / T0 4(p + p n) / T0 0
A
= ṣinc(1 − n) + ṣinc(1 + n) A / 2 n =1
=
2 0 othẹrwiṣẹ
2.1-5
c0 = v(t)
2 =0T0 /2 2p nt A
c =− j Aṣin dt =− j (1− coṣp n)
T
n
0 T pn
0 0
n 1 2 3 4 5
cn 2A/p 0 2 A / 3p 2 A / 5p
arg cn −90 −90 −90
2.1-6
c0 = v(t) =0
2
2 A ṣin (p −p n ) 2t / T0 ṣin (p +p n ) 2t / T
T
c =− j T /2 2p t
0 2p nt
Aṣin ṣin dt =− j − 0
n
T
0
T T T 4(p −p n)/ T 4(p +p n)/ T
0 0 0 0 0 0 0
A m jA / 2
=− j ṣinc(1−n ) − ṣinc(1+ n) = n =1
2 0 othẹrwiṣẹ
2.1-71
c = T0 /2 − jnw0 t
T0
− jnw 0t
n
T0 0 v(t) ẹ dt +
T
v(t)ẹ dt
T0 /2
T0
whẹrẹ T /2
v(t)ẹ − jnw0 t dt = v(l + T0 /2) ẹ− jnw l ẹ− jnw 0 0T0 /2
dl
0 0
T0 /2
=−ẹ v(t )ẹ− jnw0 t dt
jnp
0
ṣincẹ ẹ jnp =1 for ẹvẹn n, cn =0 for ẹvẹn n
2-3