Page 85 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

77
2.

,
2.10 ก ,% 2.1 , A V (F H )

V o
)
- .
ก ก (2.18) A V (F H ) = − E g = (0.707 A V (F Mid ) − 45

V o −
−
A V (F H ) = − E g = (0.707 )( 10.382 ) 45

V o −
A V (F H ) = − = − 7.34 45
E
g
= − −= − −
A = = 7.34 − −− − 45
V (F H )
2.1.4.3 ก
)
#
*
B
W
B - ก "
!
* , " ก<
W

"
ก !
"

B = F − F (2.19)
W H L

% A V ." ,dB( ! )
A
V (F Mid )

A V ( dB = 20 log 10 A V
)
A V (F Mid ) A V (F Mid )

* % A -

6
V
-

ก

A V (F Mid )
%
ก (F Mid )

A V (F Mid ) ( dB = 20 log A V (F Mid ) = 20 log 1 = 0 dB
)
A V (F Mid ) 10 A V (F Mid ) 10 1

%
"
(F
L )

A V (F L ) ( dB = 20 log A V (F L ) = 20 log 0.707 = 20 ( 0.15− ) = − 3 dB
)
A 10 A 10 1
V (F Mid ) V (F Mid )
%
"
(F
)
H
A V (F H ) ( dB = 20 log A V (F H ) = 20 log 0.707 = 20 − ) 3 dB
)
( 0.15 = −
A V (F Mid ) 10 A V (F Mid ) 10 1

ก

ก
ก