Page 31 - 30105-2003 การวิเคราะห์วงจรอิเล็กทรอนิกส์ความถี่สูง

23
1. !!" # $
%&

1.2.3.4
/ -. ' %& % (Diode Forward Resistance; r )
/
D
! + / " / ( 0, , + ก 2

055 % +'8 " 0 0 -7 & . ! ))2 ก ( '0,
- ก! 1.6 '(- ก 1.14 r -( 8ก80 ก0, ก ( I
F
D
'(& 0 :-
− r = 70 , I = 0.5 mA; '( r ≈ 40 ,I = 1 mA;
Ω
Ω
D F D F
− r = 5 ,I = 10 mA; '( r ≈ 1.4 ,I = 100 mA;
Ω
Ω
F
F
D
D
1.2.3.5 78
ก ' %& %
- ก! 1.6 t 1.25 µs , I = 10 mA '( I = 6 mA
R
F
rr
1.2.3.6 . + ก (L
)
S
&+ * ก & . &+ * ก W / "
- ก! 1.6 L = 1.5 nH " , I = 100 mA
S F
1.2.4 3
!
! ' %& %

, C '( L %7 ก' '(& / !
- ก 1.15 (ก , r
D D S

C
L S r D L S D

1.15 05'0ก1 '( - ' / $ " (Boylestad, 2002: 891)

1.2 - &/ - ' / $ " / '- ก! 1.6

ก. / ( 0, , + I = 100 mA
F
/. / ( 0, , ก'0, V = 20 V
R

9 + ก. / ( 0, , + I = 100 mA -( r = 1.4 Ω '( L = 1.5 nH
F
S
D
/. / ( 0, , ก'0, V = 20 V-( C = 200 fF '( L = 1.5 nH
S
R
D
C D (20 V) = 200 fF
L = 1.5 nH r = 1.4 Ω L = 1.5 nH
S
D
S

ก

ก
ก