§ 13-2 Some equivalent network
2121111
??? ?? VyVyI
2221212
??? ?? VyVyI
Let us add and subtract on the right side of,we have 112 ?Vy 2I?
112212221122 )(
???? ???? VyyVyVyI
222112112212 )(
???? ???? VyVyVyyIor
112112 ?? ? VyVy
2?I1?I
?
?
?
2V
?
?
?
1V
2I?
?
?
?
2V
?
?
?
1V
1I? 12y?
1211 yy ?
1222 yy ?
11221 )( ?? Vyy
If we add and subtract on the right side of,we have 221 ?Vy 1?I
221122211111 )(
???? ???? VyyVyVyI
221111221121 )(
???? ???? VyVyVyyIor
If y12=y 21,the two-port is bilateral.
2111 yy ? 2221 yy ?
21y?
aY
bY
cY
2I?
?
?
?
2V
?
?
?
1V
1I? 12y?
2111 yy ?
2122 yy ?
12112 )( ?? Vyy