Page 87 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

79
2.

Q 1 2SC3355 V CBO = 20 V,V CEO = 12 V,
Ω
V EBO = 3 V, I C (MAX) = 100 mA, r bb′ = 2 ,
P = 600 mW, β = β = 120,V BE = 0.6 V,
F
o
D
Q 1 F = =
V T 6.5 GHz, C ob 0.65 pF;
o
E
E i
g

,% 2.18

% '" ก !!

,C ก
ก(

1
ก ก (2.17) F =
H
π
2 R C
FH T
1
C =
T
π
2 R F
FH H
1
C b e ′ + C b c ′ {1 g+ m ( R out )} =
π
F
2 R FH H
1
C b e ′ + C b c ′ + C g R =
′
b c m out
π
F
2 R FH H
1
C g R = − (C b e ′ + C b c ′ )
′
b c m out
π
F
2 R FH H
g m
(
- ก (C b e ′ + C b c ′ ) = %

ก
π
2 F T
1 g m
C g R = 2 Rπ FH H − 2 Fπ T
′
b c m out
F
π
π
2 F − 2 g R F
C g R = T m FH H
′
b c m out
4π 2 R FH H T
F F
2π F − g R F F − g R F )
=
C g R = ( T m FH H ) ( T m FH H
′
b c m out
π
4π 2 R FH H T 2 R FH H T
F F
F F
( F − g R F )
g = T m FH H
m
π
F F C R
2 R FH H T b c out
′
2 g Rπ m FH H T b c out = ( T g R F )
F −
F F C R
′
m FH H
π
F = 2 g R F F C R + g R F
′
b c out
T
m FH H T
m FH H
F = g R F (2 F C Rπ T b c out + ) 1
′
T
m FH H
F T
g =
m
π
R FH F H (2 F C R + ) 1
′
T
b c out
I
(
- ก g = C (dc )
m
(k T q )
B
I C (dc ) = F T
π
F
(k T q ) R FH H (2 F C R + ) 1
′
T
B
b c out
ก

ก
ก