**T Network:**

Consider two port T Network with assumed voltages V_{1} and V_{2} and currents I_{1} and I_{2} as shown in Fig. 6.10.

Let the z-parameters of the above network are represented as follows

We know that, the z-parameters for any network can be calculated by open circuiting input and output terminals ie. by making I_{1} = 0 and I_{2} = 0

**With the port 2-2′ open circuited :**

We have, I_{2} = 0

Total impedance looking into network from port 1-1′ is equal to ( z_{1}+ z_{3}).

Hence the current I_{1} in port 1 can be calculated as

The voltage at port 2 ie. V_{2} can be given as.

**With the port 1-1′ open circuited : **

We have, I_{1} = 0

Total impedance looking back into network from port 2-2′ is equal to (z_{2} + z_{3}) Hence the current I_{2} in port 2 can be calculated as,

The voltage at port 1 ie V_{1} can be given

Consider

Substituting in

Substituting z_{3} = z_{12} in above expression,

Hence, the circuit elements of the equivalent ‘T ‘ network are as follows,