信号与系统（试卷集锦）：信号与系统01~06卷及参考答案

?S 2001M

ú??a1D I k ?| D"d k5 [?} ? 2354 ?B?sê45
 30s
 Ba?[ê45
'v5 10l5
 ?l5 3s
 30s
  ? l 5 ￥ 1?ê[? oμB? ^ ? ?5"1 p￥
h|  } ?A 5 a ￥ ? | =bpê?ê (ísb 1.RLC1 ó ~?è ^
%μ~?? q| %? A.è÷èa?′ B.è÷ èa￥ SMê C.è÷è a? q D.è ^ ? ? [ ] 2.X??| f
t
?m
a
 ? U
Q·M￥?| f 1
t
 ^ b 3.X??| f
t
?m ? U
Vr T ^ A. ε
t

 2ε
ti2
i ε
t
 3
 B.ε
til

 ε
ti2
i 2ε
t
 3
 C. ε
t

 ε
ti2
i ε
t
 3
 D. ε
til

 ε
ti2
i ε
t
 3
 4.?y ? U If
1
1e S a| f

|
1eD?|
 fJ
t
 ￥?r T ^ A. f
j
 l
 B.m
 1
 C. f
 Zt
 1b D. fB?b 1
b
@
B 5.?"d￥ Y?1 h
t? {|?| 1f ê
"d￥ ,/Y?E 1 A.h
t?
 B.fl
 h
 C.JIbbbbbD.bbbb= bbbbbB abbb 6.H?b m
l
 3
 dt￥b
2T ^ A.baB.J C.bpD.

B 2 3 4 5 ?S 2002M 4ú??a1D I k ?|D"d k5 [?} ?
 02354 ?B?s ê45
 32s
 Ba?[ê45 ('v5 16 l5
 ?l5 2 s
 32 sb ? l5￥ 1?!ês??
 êB???s?
i|??s?￥?|A5?￥ ?|= ) 1
s ??

 e t ? ?∞ ∫ 2τ δτ τ()d A
 δ B
 ε ()t ()t C
 D
 δ2ε()t ε() ()tt+ 2
X?"d± sZ?1 dy t dt yt ft () () ()+=2
? yftt() ,()sin ()01 2 + = = ε
3¤? Y?1 yt e t t () sin( )=+ ? ? 5 4 2 4 245 2 °
 t?0b?Y ?? 2 4 245sin( )t ?°1

 A
 , {?Y?s  B
 , ?Y?s  C
1?Y?s  D
× ?Y?s  3
"d2 m?m U
?"d￥?ê Y? h(t) ?@￥Z? T1

 A
 dy t dt yt xt () () ()+= B
 ht xt yt() () ()= ? C
 dh t dt ht t () () ()+=δ D
 ht t yt() () ()= ?δ 4
?| o??m ? U
 !
5 1

 ftft 12 (), () ft ft ft() ()* ()= 12 f( )0 A
 1 B
 2 C
 3 D
 4 5
X??| ￥° ú=MDft() Fj() ( )ω δ ω ω= ? 0
5 1

 ft() A
 1 2 0 π ω e j t B
 1 2 0 π ω e j t ? C
 1 2 0 π ε ω e j t ()t D
 1 2 0 π ε ω et j t ? () 6 6
X??| ?m ? U
5° ú=MD1

 ft() A
 τωττωτ 2422 Sa Sa() (+ ) B
 τ ωτ τ ωτ Sa Sa() ( 42 2 + ) C
 τωτ τ ωτ 24 2 Sa Sa() ()+ D
 τ ωτ τ ωτ Sa Sa() () 42 + 7
?| ? sY?m
a
?m (b) ? U
X? [(ft 1 () ft 2 () )] ( )ft Fj 11 = ω
5 ￥ ft 2 () ° ú=MD1

 A
 B
 Fj Fje jt 1 0 ()? ? ω ω e jt 1 0 ()ω ω? C
 D
 Fj Fje jt 1 0 ()?ω ω e jt 1 0 ()ω ω 8
 μByT L? H?M"d
 ? qY? Hj j ()ω ω = + 1 2
 ?B {? x(t) ?¤ {?| ￥° ú=MD1 Yj jj () ()( ω ωω = ++ 1 23)
5? {? x(t)1

 A
 ? B
 et ? et t3 ε() t?3 ε() C
 D
 et ?et t3 ε() t3 ε() 9
 ￥ ? fMD# l ?×1

 ft e t t () ()= 2 ε A
 1 2 2 s s + >?,Re{} B
 1 2 2 s s + <?,Re{} C
 1 2 2 s s ? >,Re{} D
 1 ? 2 2 s s <,Re{} 10
 ft t t() () ( )=??εε1 ￥ ? fMD1

 A
 1 1 s e s (? ? ) B
 1 () 1 s e s ? )C
 D
 se se s (1? ? s ()1? 7 11
 Fs s ss s() Re{}= + ++ >? 2 56 2 2 ￥ ? f QMD1

 A
 [] B
 [] ()t ()t ε ee tt?? + 32 2 ε ee tt?? ? 32 2 ε C
 D
 et δ() ()te t t + ?3 t?3 ε() 12
m
a
? ab  è ^ ^ˉè ^￥B?s
?è? L ?è? C ?cμ S ?
 hm
b
 ?ê?è ^￥ˉ?×?b

 13
 ??? | f(n) ^·

 A
 n￥|′ ^ ? ?￥
7 f(n)￥|′ ^?i￥?| B
 n￥|′ ^ ??￥
7 f(n)￥|′ ^?i￥?| C
 n￥|′ ^ ??￥
7 f(n)￥|′ ^ ??￥?| D
 n￥|′ ^ ??￥
7 f(n)￥|′ ^ ??￥?| 14
??  f(n)￥m??m
a
 ? U
* 1 f(-n+1)￥m?1m
b
?￥

 15
μsZ?￥ Q3 1yn cn c h n () () ()=+ 12 1 8 1 8 n
+31 yn n p () ()= 3 8 ε
* 1"d ￥× ? Y?1

 A
 B
 y yn h () n p () 8 C
 D
yn yn hp () ()+ dy n dn h () 16
 X? ? ?"d￥?ê? Y? ?"d {? ?m ? U
 f(n)T¨?"d?￥ ,  ?Y?1
* 1 y ? ?1 ,￥? ?1

 hn() fn() yn f () n f () A
 3? B
 4? C
 5? D
 6? ?=?s

dê5
 s

=aA b5 ('v5 9l5
 ?l5 2s
 18s ) 17
 et = t t? ? 2 εδτ()* ( ) b 18
 GLCi óè ^? 3~? H
è? è @￥?′ ^è @÷?′￥ b 19
B? ?ù= ' V ^?ù?|??i￥ Hqb 20
X?B ?ù?|￥???Mê?sY?m (a)?m (b) ? U
5??ù?| f(t)= b 21
?TX ?"d￥?ê Y?1 h(t)
5? "df ? H(s)1 b 22
 H(s)￥ ,????? %?  h(t)￥f ?? Tb 23
?ê? Y? h(n) ^· ??"d￥ ?1 H
"d￥ , ?Y?b 24
á ì| P Fz l ?￥ z|′S??1 fnz n n () ()= ? = ∞ ∑ 0 b 25
MD ×?3μsZ? H
 n51μsZ?  é? b ?a9 ?5 ('v5 10l5
 ?l5 5s
 50s ) 26
 ?m U 1 óè ^￥~?? q
 è÷èa mV
~ ? H￥è?èaμr′ p~? H￥è @μr′ I
 ipíq? ? L?í ^ ￥?éy ? Qb ω 0 5 210 10=× =rad s R/, ? U s ? =∠°50 0 UV c = 5, 9 27
X?? | f(2-t)￥o??m ? U
? f(t)￥o?b 28
X?? | x(t)￥° ú =MD X(jω )?m ? U
p? x(t)b 29
?m ? Uè ^
X?
pè ^?h{￥ü (? q Pb ut tV s () cos=+1 30
p ? f M D b ft tt tt()= ≤≤ ?≤≤ ? ? ? ? ? 01 21 0  ? 2￥ 10 31
X?è ^?m U
 t=0 [- 71ê?o 1p
è ^Xé?× ? ,t=0 H Y ào 2p
 ¨ ? f MDEpè @ i(t)￥?Y?b 32
X?? | x(t)?m ? U
 ?¨±ss+?
9 ?° ú=MDb 33
p Fz z z z() (|| )= ? > 4 1 1 2 2 ￥I ZMD f(n)
i? f(n)￥m?
-4?n?6
b 34
X?L ? H?M"d
 f
t
1 {?
 y(t)1 {
 "d￥?ê Y? ht e t t () ()= ? 1 2 ε b ? {??|
 ?¨ sp"d {￥ , ?Y? yft e t t () ()= ?2 ε f (t)b35
 ¨ ? f MDE p3[/=¨"d￥ , {?Y? y x (t)a , ?Y? y f (t)#?Y ? y(t)b dyt dt dy t dt yt e t y dy t dt t t 2 2 3 0 3 2 1 2 5 01 0 () () () () () () ++= == ? ? ? ? ? ? ? ? ?= ? ε ?S 2002M 4ú??a1D I k ?|D"d k5? Is? [?} ?
 02354 Ba?[ê45 ('v5 16l5
 ?l5 2s
  32s ) 1.B 2.D 3.C 4.B 5.A 6.C 7.A 8.B 9.C 10.A 11.D 12.B 13.B 14.D 15.B 16.C =aA b5 ('v5 9l5
 ?l5 2s
 18s ) 17
 et t?? ? 2( ) () τ ετ 18
 Q 19
A1 20
 2 32 3 4 3 3 4 1 2 5 4 11 +++ ++ +cos( ) cos( ) cos( )ω π ω 1 π ω π tt t 21
 [h(t)] 22.? 11 23
?ê?  δ()n 24
 l ?× 25
 ZMD =a 9 ?5 ('v5 10l5
 ?l5 5s
 50s ) 26
 I=5mA
L=5mH
Q=100 27. 28.? V[ A
? ^B????|￥??
 Xj()ω x(t) V[ AT?| x 1 (t)D cos500t￥ eb ? x 1 (t)￥??1 7 x 1 (t)= [()] ()Xj Sat 1 1 2 ω π = ?[ x(t)= x 1 (t)cos500t = 1 2 500 π Sa t t()cos 29
E F Z=R+j L=1+jω 1 2 ω ∴= ==I V R A 0 11 1 1 Zj 11 1 1 2 1 1 2 =+ =+ = ()|ω ω j ∴= + =? ? I j j m1 1 1 1 2 4 5 1 1 2 () 5 PIR W 00 2 11 1==?= PIR m11 22 1 2 1 2 4 5 1 1 4 1 2 5 == +?=()( ) W ∴=+=+=PP P W 01 1 2 5 7 5 12 30 2 1 1 2 2 1 2 11 1 22 2 2 2 2 .() () ( )( ) ( )( ) () () ft t t t t t t Fs SS e S e e S ss s =???+?? =? + = ? ?? ? εε ε ¨±s ?éS
 ′′ =??+? =? + ∴= ?+ = ? ?? ?? ? ft t t t SFs e e Fs ee S e S ss ss s () () ( ) ( ) () () () δδ δ21 2 12 12 1 22 2 2 2 2 31
 u ? c ()01 ? = 0 71?o 2p-a￥ˉ?×?1s 31m ( )() () () 10 sc RIs u s Es c ++ = ? Is s s s ss ()= ? + = ? + =? + 1 10 1 1 10 1 1 11 1 ∴= ? ? it t e t t () () ()δε11 32
 7 yt dx t dt () () =
5 y(t)?m ? U 5 = Yj()ω [( )] ( ) sin( ) yt Sa== ω ω ω2 2 2 ?? Yj()|ω ω= = ≠ 0 10
?  H×s+? Xj Yj j Y() () ()( )ω ω ω πδω=+0 =?+? 2 2 1 1 sin( ) () ω ωω πδω j =+ 2 2 2 sin( ) () ω ω πδ ω j 33
 Fz z zz z z z z () ()() = +? = + + ? 4 11 2 1 2 1 2 εfn n n n nn () () ( ) ()( [ ( )]())=+? +?221 211εε 13 34 1 2 1 2 1 2 1 2 2 0 0 2 .() ()*() () ( ) () ()|() ()() () yt ft ht eet eed t ee t ee t f t t t tt tt = =? =?? =? =? ??? ?∞ +∞ ?? ?? ?? ∫ ∫ ττ τ τ ετ ε τ τ τε ε ε d?  yt ht ft ee e t d eed t ee t ee t f t t t tt tt () ()* () () ( ) () ()() ()() () = =? =? =? =? ??? ?∞ +∞ ? ? ?? ∫ ∫ 1 2 1 2 1 2 1 1 2 2 2 0 2 2 ττ τ τε τε ε ε ?τ 35
Z?  H ? fMD¤
 [ ( ) ( ) ( )] [ ( ) ( )] ( )sYs sy y sys y Ys s 2 00 3 2 0 1 2 5 3 ??′ +?+= + ?? ? ∴= + ++ + + ++ Ys s ss s ss () 5 3 3 2 1 2 3 2 3 2 1 2 22 yt f ()= [ ()()( ) ][ ]() 5 31 1 2 54 31 1 2 sss eeet t t +++ =?+ ?? ? ε yt x ()= [ ()( ) ][ ]() s ss ee t t t + ++ =? + ? ? 3 2 1 1 2 2 1 2 ε yt y t y t e e e t fx t t t () () () [ ]()=+=?+ + ? ? ? 66 1 2 3 ε 14 ?S 2003M 4ú??a1D I k` ?|D"d k5` [?} ?
 02354 Ba ?[ê45 ('v5 12l5
 ?l5 2s
  24s ) ?l5 ￥ 1?!ê[?o μB? ^??5"1p￥bh|} ?A5a￥ ?|=bpêaê?ê (ísb 1.s f(t)( (t)dt￥2T1 ( ) ∫ ∞ ∞? A.f(0) B.f(t) C.f(t)( (t) D.f(0)( (t) 2. ( (t)*f(t)*( (t)￥2T1 ( ) A.( (t) B.( 2 (t) C.f(t) D.f 2 (t) 3. , {?Y? ^ ( ) A.??1?Y? B.?s1? Y? C.?s , ?Y? D.?Y?D<?Y?-μ 4.?| f(t)?5 4m ? U
??f ? F(j< )1( ) A.2Sa(< )e -j< B.2Sa(< )e j2< C.4Sa(2< )e j2< D.4Sa(2< )e -j2< t 5.?| ￥° ú=MD1 ( ) )t(e t )5j2( ε +? A. ω ω+ 5j e j2 1 B. ω? ω+ 2j e j5 1 C. )5(j2 1 +ω+ D. )5(j2 1 ?ω+? 6.??5 6m ? U?| f(t)￥° ú=MD F(j< )=R(< )+jX(< )
5?| y(t)￥° ú=MD Y(j< )1( ) A. 2 1 R(< ) B.2R(< ) C.jX(< ) D.R(< ) 7.?|q) (t)-) (t-2)r￥ ? fMD￥ l ?×1 ( ) A.Re[s]>0 B.Re[s]>2 C.? Sü ? D.?i 8.X??| f(t)) (t)￥ ? fMD1 F(s)
5?| f(at-b)) (at-b)(? a>0,b>0)￥ ? fMD 1 ( ) A. a b s e) a s (F a 1 ? B. sb e) a s (F a 1 ? C. a b s e) a s (F a 1 D. sb e) a s (F a 1 9.X??| x(t)￥ ? fMD1 X(s),5?| f(t)= ￥ ? fMD1 ( ) ∫ λλ?λ t 0 d)t(x 15 A. )s(X s 1 B. )s(X s 1 2 C. )s(X s 1 3 D. )s(X s 1 4 10.X??  f(n)?5 10(a)m ? U
5?  f(-n-2)￥m? ^5 10(b)m?￥ ( ) 11.μK é?  f(n)=3( (n)+2( (n-1)+( (n-2)ü V B ??ê ?  Y?1 h(n)=4( (n)-2 (n-1)￥ ( (n-3) (n-1)+2( (n-2)
5 -qf(n-2)) (n-2)r1( ) l 5 2s
 24s ) 0KHz￥è ??~
 ?3N l{ 14.? i óè ^~? H
è?| ^è @ ?è?| ^è @ ￥1" (vlDMê ) __ ? ^ _______￥? ?b ¨ 
f ? V U 1_______b 8.V?|? ?￥ ???? ??? ? I n
?ù?|￥?? ^ _______b f(t)=_______b 5 ?"d￥ " d f ? ( ??"d
5 , ?Y y f (n)1( ) A.12( (n)+2( (n-1)+( (n-2)+( (n-3) B.12( (n)+2( (n-1) C.12( (n)+2( (n-1)-2 D.12( (n)-( (n-1)-2( (n-3) 12.X??  f(n)=( (n)+3( A.1+3z -1 +2z -2 B.z -2 +3z -3 +2z -4 +z -5 C.z -2 +3z -3 D.z -2 +3z -3 +2z -4 =aA b5 ('v5 12l 5
 ? 13.?85 l {?￥ RLC1 óè ^ Xüo? q1 54 ￥ RLC 1 ó è ^?~?o? q1 600KHz ￥è ? 
í ^?￥ RaL íE?M
??~ è? C? ? M _______b GCL LO I & CO I & ^ __ ___b 15.?ê  f 16.f(t-t 1 )*( (t-t 2 )=_______b 17.5 17m ? U o? V ¨ ? ê 1 19.?|f ? Sgn(2t-4)￥??f ? F(j< )=_______b 20.??f ? F(j< )=( (< -2)+( (< +2)￥ ° ú = I M D 21.X?B L ? H?M " d
 ? ?|1 f(t) H￥ ,  ?Y? 1y f (t)
 H(s)1_______b 16 22.?B? ? ¨ è " ? L?± sZ ? í ? ￥ ? ? HW "d é?" d￥ H× E H
 ?3 ^ × ? " d ￥  s O A 1 H q ^ " d f ? ￥  ? ê ? S ü ? × ￥  '  E ? q ^ _______?? [b 5 s
33a34 l5 ? 5 6 s
 52 9 B ? RLC1 óè ^
~?? q1 10 4 Hz
Y?{ BW1 100Hz
 1 óí ^￥èE1 ? ? f(t)?5 26 m ? U
¨ H×Ep"d￥ , s ?"K  ^ _______?b 23.BL? H ? M ? ? H W " d ￥ _______b 24. ??"d H ?a9 ?5 ('v5 10 l5
? 25j32 5
 ? l 5 s ) 25. ! 25$
h9 ?Nè ^￥ QaLaC′b 26.?TL? H?M"d￥?ê Y? h(t)  ?Y? y f (t)b 27.  5 27m ? U"d￥±sZ?
¨ H×Ep"d￥ Y? h(t)b 28.X??| f(t)= )] 2 3cos( 3 1 ) 2 2cos( 2 1 ) 2 [cos( 2 111 π ω π ω π ω π ?+?+? tt
? f(t)￥?? k 1 ê ? ? m jk< 1 b 29.X?è @ i(t)=E+ ? mA jk< D M ? k t2sin 2 EE2 tsin 3 +
p?è @ R=1$ èE ￥μr′ I#ü (? q P T b 30 t=0 K 1 2 S 0 30.?5 m ? Uè ^X)?× ?
 H
 71 Vo pu? o p
¨ × ?Ep v (t)b 31.X?BL ? H?M ?? HW"d￥¨
Y?1 g(t)=[1-e -2t ]) (t)
¨ ? fMDEp P , ?Y?1 y f (t)=[1-e -2t -te -2t ]) (t) H￥ ??| f(t)b 32.X? ? ?"d?5 32m ? Ub 17 (1)?"d￥ Z×Z ?
(2)9 ? H(z)# h(n)b 33.X? 5 33 m ? U"d? ,h(t)￥° ú=MD1 H(j )=) (< +120)-) (<< -120),f(t)=4cos400t,s(t)=cos500t,py(t)b 34.X? ?| f 1 (t)?5 34 m ? U
?  f 1 (-2t-1),f 2 (t)=( (t+2)+( (t-2)# f 3 )=f 1 (-2t-1)*f 2 (t)￥o(t ?b

18
19
20
21 ?S 2004M 4ú??a1D I k ?|D"d k5 [?} ?
 02354 Ba?[ê45
'v5 12l5
 ?l5 2s
 24s
  ?l5  ￥ 1? ! ê[?o μ B? ^? ? 5"1p ￥
h| } ?A 5 a￥ ? |=bpêaê?ê (ísb 1
X??| f(t)￥o??5 1m ? U
5 f
t
￥ Vr T1




 A
 t) (t) B
 (t-1)) (t-1) C
 t) (t-1) D
 2(t-1)) (t-1) 2
s T ￥s2T ^




 ∫ ? δ+δ++ 4 4 2 2)]dt-(t2(t))[23( tt A
 14 B
 24 C
 26 D
 28 3
X? f(t)￥o??5 3
a
m ? U
5 f(5-2t)￥ o?1




 4
?ù ? ? ￥?LW?D




 A
 ? ?μ1 B
 ? zμ1 C
 ? ?ùμ1 D
?ù? ? zμ1 5
? ? ?  ?|￥ zF z
5 ?￥??{ z




 A
?M B
MN C
M z D
D ? zí1 6
 ?T ??|sYYV"df ?1 H
j<
 ￥"da
 ¤?M]￥Y?
 * 1? ?? |




 A
B?M] B
B??] C
o?1 , D
 V[?] 7
 f(t)= ￥ ? fMD1 F
s
 =)t(e t ε 1 1 ?s
O l ?×1




 22 A
 Re[s]>0 B
 Re[s]<0 C
 Re[s]>1 D
 Re[s]<1 8
f ? ￥?H ? fMD F
s
??




 ∫ ? ∞? δ= 2t dx)x()t(f A
 1 B
 s 1 C
 e -2s D
 s 1 e -2s 9
?H ? f MD F
s
 = 2 2 + +? s e )s( ￥ef ? f(t)??




 A
 e -2t ) (t-1) B
 e -2(t-1) ) (t-1) C
 e -2t ) (t-2) D
 e -2(t-2) ) (t-2) 10
X? f 1 (n)=( 2 1 ) n ) (n)
f 2
n
=) (n)- ) (n-3), 7 y(n)=f 1 (n)*f 2 (n),5? n=4 H
 y(n)1




 A
 16 5 B
 16 7 C
 8 5 D
 8 7 11
?  f(n)T¨?BL ? H?M ? ? HW"d
 ?¤1? Y?1 y 1 (n)
<?Y? 1y 2 (n)
 , ?Y?1 y 3 (n)
 , {?Y?1 y 4 (n)b5?"d￥" ?f ? H
z
1




 12
??  x(n)￥ ZMD1 X
z

5 (
 0.5) n x(n)￥ ZMD1




 A
 2X
2z
 B
 2X(-2z) C
 X(2z) D
 X(-2z) =aA b5
'v5 12l5
 ?l 5 2s
 24s
 h ?l5￥ bì?A ??s?bpAa?A (ísb 13
 ¨]B FèEa è??è?
 sYF? RLC1 ó~?è ^? GCLi ó~?è ^
 ~? ? qsY1< 1 ?< 2
5< 1 D< 2 ￥1"1 _________________b 14
 RLC1 ó~?è ^?
 ?éy ? Q′v
 5~?è ^￥ê4? ________________b 15
?TB L? H?M"d￥?ê Y?1 h(t)
5?"d￥¨
Y? g(t)1_________b 16
?TBL? H?M "d￥ {? 1f(t)
 ,  ?Y?1 y f (t)=2f(t-t 0 )
5 ?"d￥? ê  Y? h(t)1_________________b 17
?TBL ? H?M"d￥?ê Y? h(t)=) (t)
5??"d￥ {??| f(t)=t) (t) H
  , ?Y?1 _________________b 18
?5 18m ? U?ù ? ?|￥° ú=) ?￥??[" ? a n 1_________________b 23 19
X? x(t)￥° ú=MD1 X
j<

* 1 x(t-t 0 )￥° ú=MD1 _________________b 20
X? x 1 (t)=( (t-t 0 )
x 2 (t)￥??14
@( (< +< 0 )+( (< -< 0 )
B
O y(t)=x 1 (t)*x 2 (t)
* 1 y(t 0 )= _________________b 21
?X? f 1 (t)￥ ? fMD F 1
s
 = )e( s s? ?1 1
5 f(t)=f 1 (t)* f 1 (t)￥ ? fMD F
s
 = _________________b 22
 X?L ? H?M"d￥ Y?1 h(t)=(1-e -t )) (t)
 5  "df ? H
s

" __________b 23
L? H?M ?? HW"d￥E m?5 23 m ? U
 S ?1 ,
5 í ??"d {? {1"￥ S×Z?1 _________________b



24
 L? H ?M ?? HW"dsY1 S 1 ? S 2
 S ? (1 ,b | ??| f(n)5YV S 1  YV S 2
 ¤?Y? y 1 (n)
| ??| f(n)5YV S 2 YV S 1
 ¤?Y? y 2 (n)b5 y 1 (n)D y 2 (n) ￥1"1 _________________b ?a9 ?5
'v5 10 l5
5 25
5 32
 ? l5 5s
5 33
5 34
 ?l5 6s
  52s
 25
 5 25m ? Uè ^?
 R
" 10$
 L
" 0.01H
 C
" 10 F.
pè ^~? H￥??? q< 0
 ?éy ? Q
[#Y?{ BW.
?< 0 ? BW￥?ê1 rad/s
 26
X?B L? H?M"d￥ H×E m?5 26m ? U b

1
 y(t)D f(t)- W￥1" T


2
p? "d￥?ê Y? h(t)b 24 27
X? 5 27m?
 f(t)1 {?è a
 y(t)1 {èa
è ^￥ HWè ? RC
" 1.

1
  ?è ^￥±sZ?


2
p ?è ^￥?ê Y? h(t)b 28
p" f ? x(t)=Sa( 2 t c ω )￥° ú=MDb 29
 X?B L? H?M ?? HW"d￥?ê Y? h(t)=( (t-t 0 )
? x
t
 ￥° ú =MD1 X(j< )= ω+ j1 1
¨?×sEp? {?1 x(t)+x(t-1) H" d￥ , ?Y? y f (t)b 30
X?B L? H?M"d￥ {? f(t)D { y(t)￥1" V¨/ ±sZ? í ?






)t(f)t(y dt )t(dy dt )t(yd =++ 23 2 2
?f(t)=2) (t)
¨ ? fMDZEp?"d￥ , ?Y? y f (t)b 31
X?B ?? HW"d￥μsZ?1 y(n)
 2 1 y(n-1)=f(n)
 k ¨ ZMDE

1
p" d?ê? Y? h(n)


2
?" d￥ , ?Y?1 y(n)=3[( 2 1 ) n
 ( 3 1 ) n ]) (n) H
p ??| f(n)b 32
X?? | f 1 (t)D f 2 (t)?5 32m ? U


1
 y(t)=f 1 (t)* f 2 (t)
N s￥B?V U T


2
s p y(t)￥V ? Tb 33
X?? | x(t)ay(t)￥?? X(j< )aY(j< )?5 m 33(a)m#5 33(b)m ? U
p¨ x(t)V U￥ y(t)b 25 34
X? RLC1 óè ^?5 34m ? U
? R
" 2$
 L
" 1H
C
" 0.2F
i(0 - )
" 1A
u c (0 - )=1V
 {??| u i (t)=) (t)b k??"d￥ˉ?×?m
i9 ?è @ i(t)b
4 U
 cos(< 0 t) o1 2 0 2 ω+s s
 26 ?S 2005M 4ú??a1D I k ?|D"d k5 [?} ?
 02354 Ba ?[ê45 ('v5 12l5
 ?l5 2s
 24s )  ? l5 ￥ 1?!ê[ ?oμB? ^??5" 1p￥
 h| } ?A 5a￥ ? |= bpêa ê?ê ( ísb 2.s T ?? ( ) ∫ ∞ ∞? ?δ? dt)t()t3cos( A.1 B.0 C.-1 D.-2 3.X??| f(t)?5 3(a)m ? U
5 f(-2t-2)15 3(b)m?￥ ( ) 4.X?BL? H?M"d5 4(a)m ? U?|￥ ?/￥ , ?Y??5 4(b)m ? U
5 ?5 4(c)m ? U?|￥ ?/￥ , ?Y?15 4(d)m? ￥ ( ) 27 5.5 5m? f(t) ^?ù1 T￥?ù?|
 f(t)￥??f ?? T￥° ú=) ?" ?￥+? ^ ( ) A.?μ??[ B.;μ?? [???[
?μ° @[ C.;μ?? [?μ??[ D.?μ??[ 6.X? F(j )=
5 F(j ) ??￥ HWf ?1 ( ) ω ? ? ? >ω <ω 2||0 2||1 ω A. t tsin π B. t t2sin π C. t tsin D. t t2sin 7.5 7m ? U ?| f(t)￥° ú=MD1 ( ) A.2Sa( )sin2 B.4Sa(ω ω ω)sin2ω C.2Sa( )cos2 D.4Sa(ω ω ω)cos2ω 28 8.f(t)=e -(t-2) )2t( ?ε -e -(t-3) ε (t-3)￥ ? fMD F(s)1( ) A. 1s ee s3s2 + ? ?? B.0 C. 1s ee s3s2 ? ? ?? D. )1s)(1s( ee s3s2 +? ? ?? 9.`f ? F(s)= 2]s(Re[ 2s3s 1 2 > +? )￥ef ?1 ( ) A.(e -2t -e -t )ε (t) B.(e 2t -e t )ε (t) C.(e -t -e -2t )ε(t) D.(e t -e 2t )ε(t) 10.?"d Y?1 h(t)
/  T? V? ^"df ? H(s)￥ Vr T1 ( ) A. 1s3s e 2 st ++ ? B. 2 )1s( t + C. )1s(s4 e 2 sT + ? D.3e -2t ε(t-2) 11.?  f 1 (n)? f 2 (n)￥o??5 11 m ? U
 ! f(n)=f 1 (n)*f 2 (n)
5 f(2)?? ( ) A.0 B.1 C.3 D.5 12.?  f(n)=2 -n ε(n-1)￥?H ZMD F(z)?? ( ) A. 1z2 z 1 ? ? B. 1z2 1 ? C. 1z2 1 + D. 1z2 z ? =a A b5 ('v 5 12l5
 ?l5 2s
  24s ) 13.RLCi ó ~?è ^~? H
i óè ^  ?, Y 0 =________b 14. ? ? ?| [ε(t)- (t-1)]üVBL? H?M"d￥ , ?Y?1 [g(t)-g(t-1)]
5?"d￥ ?ê Y? h(t)1________b ε 15.  T [e -2t ε(t)]*ε(t)________b 16.X?BL ? H?M"d
 ? ??|1 f(t) H
 ??Y?1
3sint-2cost
 ε(t)
? ? ?|1 2f(t) H
 ?? Y?1 (5sint+cost)ε(t)
5 ? ? ?| 1 3f(t) H
 ?? Y? 1 ________b 17.B??ù ? ? ?| f(t)￥ ? z1 τ ,τ =0.2 e
?ù1 T e
T=1 e
5 f(t)￥ 29 ° ú=) ?￥???￥?B?V ,?￥? q| ________~o)b 18.?üB? μK??ù ￥d?ù? | f(t)é??ù?ü?? 1f T (t)a
 f T (t)￥??D f(t)￥? ? ??? ￥uY ^ ________ 19.L? H ?M"d￥"df ? H
)3j)(2j( 2 )j +ω+ω =ω
5?"d￥?ê Y? h(t) 1________b 20.f(t)=t (t)￥ ? fMD F(s)1________b ε 21.5 21m ? Uè ^?
 ? U s (t)1 {??|
 5 , ?Y? i f (t)￥ ? fMD I f (s)￥V U T 1 ________b 22.5 22m ? U"d￥"df ?1 ________b 23.5 23m ? U"d?
 {?? 1 f(n)
 {? 1 y(n)
ò0"d￥?ê? Y?sY 1h 1 (n)=
5"d￥?ê? Y? h(n)=________b )1n()n(h),1n( 2 +δ=?δ 24.μKé ?  f(n)￥?H ZMD 1F(z)=1+z -1 +6z -2 +4z -3 ,?¨?ê?  V U?? 
5 f(n)=________b ?a 9 ? 5 ('v 5 10l5
 5 25i5 32
 ?l5 5s
 5 33i5 34
 ?l5 6s
  52s ) 25.?5 25m ? Uè ^
 X?è÷èaμr′ U=1mV
 pè ^ ￥%μ~??? q ,~?è ^￥?éy ? Q
[#~? Hè? èa￥μr′ U 0 ω co b 30 26.X?BL ? H?M"d￥ {? f(t)D { y(t)￥1"¨/ TV U y(t)= ∫ λ λ ? λ? t 0 d RC e RC 1 )t(f ? RaC ( 1è ?
 ?¨ sEp ??|1 e -2t )t(ε H"d￥ , ?Y?b 27.X ??5 27(a)m ? U￥ L? H?M "d
? {? f 1 (t)= ε (t)￥ ,  ?Y ?1 y 1 (t)= (t)-ε (t-1)b5 27(b)m ? U"d?5 27(a)m ? U"d) ó7?
p?"d {? 1f ε 2 (t)= (t)- (t-2) H￥ , ?Y? yε ε 2 (t)b 28.X?? | f(t)?5 28m ? U
¨ H×±s?ép f(t)￥° ú=MD F(j )b ω 29.X ? B ? L? H ?M "d￥ ?Y f ?1 H(jω)(Mê ?? 0)( =ω? )b k￡ üN "d[ / ??| f 1 (t)= )t( c δ ω π ? f 2 (t)= t tsin c c ω ω ￥ , ?Y? ^M]￥b 31 30.X?B L? H?M "d￥"d f ?1 H(s)= 8s6s 1 2 ++
p {?1 f(t)=e -t )t(ε
O y(0 - )=0, (0y′ - )=1 H"d￥? ?Y? y(t)b 31.X?L ? H?M"d￥ {?1 f(t)=sintε (t)
" d￥ Y? h(t)=e -t ε (t)
p"d￥ , ?Y? y f (t)￥ `f ? Y f (s)b 32.?5 32 m ? UL? H?M ?? "db (1) k "df ? H(z)
(2)? {??  f(n)= (n) H
p"d￥ , ?Y? y ε f (n)b 33.X?BL ? H?M"d￥ Y?1 h(t)=e -t ε (t) ? ??|1 f(t)=[ (t)- (t-2)]+ε ε )2t( ?βδ
C1p "d t>2 H ￥ , ?Y?1 0
 k ? ? β￥|′b 34.X??ù ? ? èa?| f(t)?5 34(a)m ? U
 ? f(t)T¨??5 34(b)m ? U RLè ^ H
 y(t)1 { èa?|b (1)ü f(t)Z???f ?? T￥° ú=) ? ; (2)"d?Yf ? H(jkω 1 )￥V U T ; (3)"d × ?Y? Y(jkω 1 )￥V U T
 ip { y(t)￥BQa? Q~o HW f ?V U Tb 32 ?S 2006M 4ú??a1D I k ?|D"d k5 [?} ?
 02354 Ba?[ê45
'v5 12l5
 ?l5 2s
 24s
  ?l5  ￥ 1? ! ê[?o μ B? ^? ? 5"1p ￥
h| } ?A 5 a￥ ? |=bpêaê?ê (ísb 1
5 1m ? U= g? ? Z? ?? Z 11 1



 A
 Z 1 B
 Z 2 C
 Z 1
 Z 2 D
 Z 2
 Z 3 2
RaLaC1 ó~?è ^
 ?1 ó~?? q1 f 0
? {??|? q f>f 0 H
 N Hè ^1




 A
?? B
?? C
E? D
íE?? 3
?| f(5-3t) ^




 A
 f(3t)·M 5 B
 f(3t)PM 3 5 C
 f(
 3t)PM 5 D
 f(
 3t)·M 3 5 4
s T ??




 [ ∫ +∞ ∞? ?++ tdttt cos)()( πδπδ ] A
 0 B
 1 C
 2 D

 2 5
/ òV r T?p￥ ^




 A
 )()0()()( tfttf δδ = B
 )()(*)( 00 ttftttf ?=?δ C
 D
 )()()( 00 tfdttttf =? ∫ +∞ ∞? δ )()0()()( 000 ttfttttf ?=?? δδ 6
?5 6m ? U￥?ù?| f(t)￥° ?=) ?? ?c￥? qs  ^




 A
??[￥}Q~o
c° @s  B
??[￥Q~o
í° @s  C
??[￥Q~o
í° @s  D
??[￥}Q~o
c° @s  33 7
X? f (t) )( ωjF? ,5 f

 2 t
￥° ú=MD1




 A
 )2(2 ωjF? B
 )2(2 ωjF ? C
 ) 2 ( 2 1 ωj F D
 ) 2 ( 2 1 ωj F ? 8
 ! f (t) )( ωjF?
? ω ω 2 5 1 22 1 )( j ejFtf ? ? ? ? ? ? ? ?
5 1




 )( 1 tf A
 f(-2t+5) B
 f(2t-10) C
 f(2t-5) D
 f(-2t-5) 9
? f (t)
5 f(3t-7)￥ ?? ? ?MD1




 )(sF? A
 s e s F 3 7 33 1 ? ? ? ? ? ? ? B
 s e s F 7 33 1 ? ? ? ? ? ? ? C
 s e s F 7 33 1 ? ? ? ? ? ? D
 s e s F 3 7 33 1 ? ? ? ? ? ? 10
X?? H ?? ? ?MD 2 )( )2( + = ?? s e sF s
5ef ? f (t)1




 A
 B
 )1( 2 ? ? te t ε )1( )2(2 ? ?? te t ε C
 D
 )2( 2 ? ? te t ε )1( )1(2 ? ?? te t ε 11
 RaLaC1 óè ^ ˉ?×E F1




 A
 SC SL R ++ 1 B
 SC SLR 1 ++ C
 jSC jSLR 1 ++ D
 jSC jSL R ++ 1 12
 f (n)?5 12m ? U
5 y(n)=f(n)*f(n)1




 A

`1
 1
 1
b B

`2
 2
 2
b C

`1
 2
 2
 2
 1
b D

`1
 2
 3
 2
 1
b 34 =aA b5
'v5 12l5
 ?l 5 2s
 24s
 h ?l5￥ bì?A ??s?bpAa?A (ísb 13
?5 13m ? U
= g? ? Y? ? y 11 1________________b 14
X? f(t)=) (t)-) (t-2)
5 f(3+2t)￥Vr T1 ________________b 15
X? f(t)= ) (t+1)+) (t)-2) (t-2)
5 dt tdf )2( ? ￥Vr T1 ________________b 16
  (1
 2t)) (t)*) (t)?? ________________b 17
5 17m? | f(t)￥° ú=MD1 ________________b 18
X? f(t) )( ωjF?
55 18mo?￥ F
0
1 ________________b 19
  t) (t)*) (t)￥ ?? ? ?MD1 ________________b 20
? f(t) F(s)
5? dt tdf )( ￥ ?? ? ?MD1 ________________b 21
X?` f ? F(s)= )12( + ? ss e s
5 f (t)1________________b 22
  y(n)=2 n ) (n)*3 n ) (n)?? ________________b 23
? 5 23m
 í ? ??"d ￥μsZ? ________________b 24
   y(n)=) (n)*) (n)￥ ZMD1

________________b ?a 9 ?5 ('v5 10l5
 ?5 25j5 32
 ?l5 5s
 5 33j5 34
 ?l5 6s
  52s ) 35 25
 RaLaC1 ó~?è ^
? {? tu s 7 10cos210= mV H
è ^~ ?
? L=250 H
è E Rh{? q1 200 W
p Caè @ I 0 b? u s =10 2 cos10 5 t mV
N Hí ^è @ ^v? I 0 ? ^l? I 0 ? 26
 f(t)D h(t)￥o??5 26m ? U
¨ m3Ep y f (t)=f(t)*h(t)b 27
 L? d HM"d f(t)
" e -t ) (t) ?/￥ , ?Y?1 y(t)=t[) (t)-) (t-1)]-(t-2)[) (t-1)- ) (t-2)]
p"d￥ Y? h(t)b 28
?5 28m
 ! f 1 (t) F? 1 (j< )
f 2 (t)? F 2 (j< )
 kp F 1
j<
# F 2
j<
 b
V ?¨ F 1
j<
p F 2
j<

 29
 X?" df ? H
S

" )4)(2( 3 ++ SS S
 k ? ,?s?m
 p"d￥ Y? h(t)
 a ü"d ^?×?b 30
? í ?" d￥±sZ?1 )()(23 2 2 tfty dt dy dt yd =++
O f(t)=e -3t ) (t) y(0
 )
" 1
 y￡(0
 )=1
py(t)b 31
X? ? ?"d￥"df ? H(Z) = 6 1 6 1 2 2 2 ?? + ZZ ZZ
p í ?N"d￥μsZ?
ip?ê ? Y? h(n)b 32
 X?L? H? M "d￥? Y f ? H(j< )?5 32m ? U
 ? {? 1f (t)=1+cost
p ?"d￥ ,  ?Y? y f (t)b 36 33
è ^? 5 33 m ? U
X?
 k¨ˉ? × sE
 pt>0 H u(t)b AttfVtetf t )(5.1)(,)(2)( 21 ?== ? εε 34
X? í ? ??"d￥μsZ?1 y(n)+3y(n-1)+2y(n-2)=f(n)-f(n-1) y(-2)=0 y(-1)=1 f(n)=3(2) n ) (n) k ?¨ Z× sEp y(n)
i?"d￥Emb 37