Page 160 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

152

3.

3.7.4 ก
ก

@A*

กCK "

Ω
Ω
* ก,
. @ ก
ก V = 12 V, R = 75 , R = 75 ,T = 25 C;
CC g L A

C F 1
Q 1
V o
E E 1 i E 2 i
g

Ω
C F = 5.5 MHz, B = ± 60 kHz,V = 0.6 V, β = β = 85, C = 1 pF, F = 2 GHz, r bb′ = 2 ;
F 1 R W BE F o ob T
+ 3.21
, "- /(,. . !(ก01 & "- ก
'

3.7.4.1 ก
ก,
.
I
C
k T
F T ( B ) q
ก !ก (2.20) I C (dc ) =
F
R FH H ( 2 F C Rπ T b c out + ) 1
′
ก
"
F = 5.5 MHz, R FH = R CF 2 , R out = R L , C b c ′ = C ob ;
H
ก !ก (3.30) Z = R + R (r + r )}
incf CF 2 { BB bb′ b e ′

ก R ! 9 ! 8 % ($
BB

Z incf = ( R CF 2 + r bb′ + r b e ′ )

ก C & ก 9 !&

ก+ %! 600 Ω
$
Z incf %& ! 9 600 Ω
1
F
β
r b e ′ = o
g m
I

ก g = C (dc ) %
m
V T
β V
r b e ′ = o T
I
C (dc )
β V

9 r b e ′ = o T "
!ก Z incf %
I
C (dc )
β V
Z = R + r + o T
incf CF 2 bb′
I C (dc )
β V
o T = Z − ( R + r )
I C (dc ) incf CF 2 bb′

ก

ก
ก