Two port parameters-Z,Y,h,g,ABCD parameters

This page covers two port parameters.It includes impedance(Z parameter),admittance(Y parameter),h-parameter,g-parameter and ABCD parameter.

2 port parameters

As shown in the figure, two port network is special case of multiport network in which each port consists of two terminals.


V1 = Z11*I1 + Z12*I2
V2 = Z21*I1 + Z22*I2

Z-parameters are also called as open circuit impedance parameters.


I1 = Y11*V1 + Y12*V2
I2 = Y21*V1 + Y22*V2

Y-parameters are also called short circuit admittance parameters.


V1 = h11*I1 + h12*V2
I2 = h21*I1 + h22*V2

Hybrid parameters are used in constructing models for transistors.


I1 = g11*V1 + g12*I2
V2 = g21*V1 + g22*I2

ABCD-parameters or T-parameters

V1 = A*V2 + B*I2
I1 = C*V2 + D*I2

Following table mentions condition for a network to be symmetrical and reciprocal.

Reciprocal Symmetrical
Z12=Z21 Z11=Z22
Y12 = Y21 Y11 = Y22
|A B|
|C D| is equal to one.
A = D
h12 = - h21 |h11 h12|
|h21 h22| is equal to one.
g12 = -g21 |g11 g12|
|g21 g22| is equal to one.

RF and Wireless Terminologies