T Network:

Consider two port T Network with assumed voltages V₁ and V₂ and currents I₁ and I₂ 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 I₁ = 0 and I₂ = 0

With the port 2-2′ open circuited :

We have, I₂ = 0

Total impedance looking into network from port 1-1′ is equal to ( z₁+ z₃).

Hence the current I₁ in port 1 can be calculated as

The voltage at port 2 ie. V₂ can be given as.

With the port 1-1′ open circuited :

We have, I₁ = 0

Total impedance looking back into network from port 2-2′ is equal to (z₂ + z₃) Hence the current I₂ in port 2 can be calculated as,

The voltage at port 1 ie V₁ can be given

Consider

Substituting in

Substituting z₃ = z₁₂ in above expression,

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