TWO PORT NETWORK CIRCUITS AND NETWORK

1. CIRCUITS AND NETWORKS
Pinky Chaudhari (131040109006)
Vibha Patel (131040109044)
Samia Zehra (131040109052)

2.  Two Port Network
 N-port Network
 Z Parameter
 Y Parameter
 ABCD Parameter
 Inverse ABCD Parameter
 Hybrid Parameter
 G Parameter
 Conversion of Two-port parameters
 Interconnection Of Two Port Network

3. If a network is having two pairs of terminals or two
ports then it is called as two port network.
I1 I2
+
Input
The Network
Output
_ Port
Port
_
+
V1 V2

4. A network having N numbers of ports ; is called N
port network.

5. 1) Impedance (z) Parameter
2) Admittance (Y) Parameter
3) Hybrid (h) Parameter
4) Inverse Hybrid (g) Parameter
5) ABCD Parameter
6) Inverse ABCD Parameter

6. The impedance or Z parameter of a two port network is
defined by
V z z I
V z z I
 1     
   11 12 1
   
 2   21 22   2

or in scalar form
V z I z I
V z I z I
 
 
1 11 1 12 2
2 21 1 22 2

7. The Z parameters can be found from
V V
1 1
z z
 
11 12
I I
1 I  0 2 I

0
2 1
V V
2 2
z z
 
21 22
I I
1 I  0 2 I

0
2 1
These parameters are call open circuit impedance parameters

8. The admittance or Y parameter of a two port network is
defined by



V







 







1
2
y y
11 12
21 22
1
2
V
y y
I
I
or in scalar form
I y V y V
I y V y V
 
 
1 11 1 12 2
2 21 1 22 2

9. The Y parameters can found from
I I
1 1
y y
 
11 12
V V
1 V  0 2 V

0
2 1
I I
2 2
y y
 
21 22
V V
1 V  0 2 V

0
2 1
These parameters are call short-circuited admittance parameters

10. The defining equations are:



V









 



V



2
2
1
1
I
A B
C D
I
1
V
2
V
A
V
1
I
B
I2 = 0 
2

V2 = 0
1
V
2
I
C 
I
1
I
D


I2 = 0 2
V2 = 0

11.       
             
V V
2 A B 1
I C D I
2 1
V V
2 2
    
A B
V I
1 I  0 1 V

0
1 1
I I
2 2
    
C D
V I
1 I  0 1 V

0
1 1

12. H-parameter is the combination of Z and Y parameter defined
by
V h h I
I h h V
 1     
   11 12 1
   
 2   21 22   2

or in scalar form
V h I h V
I h I h V
 
 
1 11 1 12 2
2 21 1 22 2
H-parameter is commonly used in transistor
modeling.

13. The h parameters can found from
V z z
1
1 12 21
h    z

11 11
I y z
1 0 11 22
2

I y z
2 21 21
   
2
   
1
   
1
21
1 
0 11 22
2 12 21
22 22
2 
0 11 22
1 12 12
12
2 0 11 22
1
V
V
I
I
h
I y z
I y y
h y
V y z
V y z
h
V y z


14. g-parameter is defined by
I g g V
V g g I
 1     
   11 12 1
   
 2   21 22   2

or in scalar form
I g V g I
V g V g I
 
 
1 11 1 12 2
2 21 1 22 2
g-parameter is an alternative form of hybrid representation.

15. The g parameters can found from
I y y h
1
1 12 21 22
g    y
 
11 11
V z y h
1 0 11 22
2

V z y h
2 21 21 21
2
1
1
21
1 
0 11 22
2 12 21 11
22 22
2 
0 11 22
1 12 12 12
12
2 0 11 22
11 22 12 21
1
I
I
V
V
g
V z y h
V z z h
g z
I z y h
I z y h
g
I z y h

h h h h h

     

    

     

where   

16. Two port parameters can be converted to any form as follows
 I YV



 
1
I
V z z I
V z z I
     
      
     
V  ZYV
V  ZI
From



V











1
2
y y
11 12
21 22
2
V
y y
I
And
1 11 12 1
2 21 22 2
1 Z  Y and 1 Y  Z

17. z z
  
22 12
 y y    Z  Z

    
 y y   z z

   
y y
  
 z z    Y  Y

    
 z z   y y

   
Z z z z z
Y y y y y
  
  
11 22 12 21
11 22 12 21
11 12
21 22 21 11
Z Z
22 12
11 12
21 22 21 11
Y Y
where

19. Three ways that two ports are interconnected:
* Parallel
* Series
* Cascade
 y    y    y

a b  z    z    z
 a b
 T    T   T
 a b
ya
yb
za
zb
Ta Tb
Y parameters
Z parameters
ABCD parameters