Page 141 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

133

3.

3
×
×
R R 2 30 10 × 49 10 3
B
1 b
R TH = = = 18.607 kΩ
×
×
3
( R B 1 + R B 2 ) ( 30 10 + 49 10 3 )
(7.443 0.6− )
I = = 41.774 µA
B
18.607 10 + ( { 120 + ) 1 1.2 10 3 }
×
3
×
ก !ก (2.4) I = β I = 120 41.774 10 − 6 = 5.012 mA
×
×
C F B
ก !ก (3.12) V CE = V CC − ( β + ) 1 I R
F
B E
×
V = 12 − ( 121 41.774 10× × − 6 × 1.2 10 3 ) = 5.934 V
CE
" )
I = == = 41.774 µA, I = == = 5.012 mA %V CE = == = 5.934 V
B
C
3.5.2 ก

.
BCCD
ก
++ #
(

, "- J - / ! "- R % C "
ก "
+;
ก ! 8 %
n
n
($ C
b c ′
3.5.2.1 ก
$

'
g , r F
m b e ′ ′′ ′ R (L 21 )
I I
c
d
c
d
ก !ก (1.9) g = C ( ) = C ( )
m )
V (k T q
T B
β
ก !ก (1.10) r b e ′ = o
g
m
T
1 r bb′
B b′ C T 2
L 11 L 21 a
N 11 N 21 C BT r b e ′ V g V
C b e ′ m b e ′
R g b e ′
75Ω E i L 12 R L(ab)
C CT(ab)
E b
g
E

Ω
V = 0.6 V, C = 0.5 pF, F = 6 GHz, r = 5 , β = 120, C = 20 pF, C = 25 pF,T = 25 C;
BE ob T bb′ F CT BT A
T 1 L = 1 µH, L 21 = 1 µH, N 11 : N 21 = 1:1;
11
T 2 L 22 = 1.5 µH, L = 375 nH, L 32 = 15 nH, N 22 : N 12 : N 32 = 10 :5 :1;
12
+ 3.14 00> ก % , "- J - /
(
ก + 3.14 ก + %! 9 F ( R L 21 ) .# ก( ก L (C BT C b e ′ ), 8
21
9 r ! 9 & % ($ ( K/ %ก
$)
bb′
1
ก !ก (3.1b) F =
R
2π LC
ก

ก
ก