Page 72 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

64
2.

E = I R + I Z = I ( R + Z )
g i g i in i g in
E g
I =
i
( R + Z in )
g
E = I Z
i
i in
E Z
E = g in
i
( R + Z in )
g
V o V o E i V o E Z
g in
A = − = − × = − ×
V (F Mid ) E g E i E g E i E g ( R + Z in )
g
V o V o Z in g r Z Z in
′
m b e out

$
A V (F Mid ) = − E g = − E i × ( R + Z in ) = − Z i × ( R + Z in ) (2.11)
g
g
(
- ก
V (/ ก
" ก ! E 180 # (,5

o g
"

$
-
−
) ! & !! & & (

A # ( . ! ( )
.
" (/
V (F Mid )
-
"
ก ( . ! ก
,

- ก
ก . ก I
2.1.2.4.2 A ( i F Mid ) R L
'" E . - E " ก (. -
ก
ก I
,% 2.7 ก A ( i F Mid ) g i
b
I R
A ( i F Mid ) = I L
E = I b b ( bb′ + r b e ′ )
r
i
E
I = i
b )
(r bb′ + r b e ′
E r
i b e ′
V b e ′ = I r = + )
b b e ′
r
( bb′ r b e ′
g V R g E r R
′
′
=
m i b e C
m b e C
I R L = ( R + R L ) (r bb′ + r b e ′ )( R + R L )
C
C
I R g E r R (r bb′ + r b e ′ )
′
A ( i F ) = L = m i b e C ×
Mid
I b (r bb′ + r b e ′ )( R + R L ) E i
C
I R g r R
′

$
A = L = m b e C (2.12)
( i F Mid ) R + )
I
b ( C R L
V o V o
,
2.3 ก ,% 2.1 , A V (F Mid ) = − , A V (F Mid ) = − A ( i F Mid )
E
i E g
V o g r Z g r R R
′
′
m b e out
m b e C L
- .
ก ก (2.10) A V (F Mid ) = − E i = − Z i = − ( bb′ + r b e ′ )( C R L )
R +
r
ก

ก
ก