What is Two port and One port Networks???

• ONE PORT NETWORK:-

➝ A Network is considered as a rectangular box with Two input terminal are called as a ONE PORT OR SINGLE PORT NETWORK.

Fig(a) ONE PORT NETWORK

• TWO PORT NETWORK:-

➝A Network is considered as a rectangular box with Two input terminal and Two output terminal are called as a Two port Networks or Four terminal Network.

Fig(b) TWO PORT NETWORK

• 
  DIFFERENT PARAMETERS OF TWO PORT NETWORK:-

1. IMPEDANCE OR OPEN CIRCUIT "Z" PARAMETER.
2. "Y" - PARAMETER OR SHORT CIRCUIT PARAMETERS.
3. "H" - PARAMETERS OR HYBRID PARAMETERS.
4. TRANSMISSION PARAMETERS OR ABCD PARAMETERS.

❋ OPEN CIRCUIT "Z" PARAMETER:-

Fig(c) Z PARAMETER

⇨Consider the above Network in this two port network each input voltage V1 and output voltage V2 is expressed in terms of input current I1 and Output Current I2 respectively.

⇨According to ohm's law........

                           V = R×I 

   But here,.  R = Z so,

                          [V] = [Z]×[I] ................(1)

⇨In matrix form..........

                                                     ..................(2)

⇨From the figure of two port network we can write down the equation of V1&V2 which is exactly Same as KVL equation..........

                   V1 = Z11×I1 + Z12×I2 ..............(3)

                   V2 = Z21×I1 + Z22×I2 ..............(4)

➝ASSUMING OUTPUT PORT IS OPEN CIRCUITED (I2=0):-

    Put I2= 0 in Equation Number (3)&(4)......

                    V1= Z11×I1 

                ∴ Z11 = V1/I1|I2=0 ......................(5)

  And.         V2 = Z21×I1 

                ∴ Z21 = V2/I1|I2=0 ......................(6)

➝ASSUMING INPUT PORT IS OPEN CIRCUITED (I1=0) :-

   Now put I2=0 in Equation Number (3)&(4)......

                     V1 = Z12×I2 

                  ∴ Z12 = V1/I2|I1=0 ....................(7)

                    V2 = Z22×I2 

                     V2 = Z22×I2

                  ∴ Z22 = V2/I2|I1=0 ................,...(8)

Where ;

• Z11&Z22 = DRIVING IMPEDANCE OF INPUT AND OUTPUT RESPECTIVELY.
• Z12&Z21 = TRANSFER IMPEDANCE OF INPUT AND OUTPUT RESPECTIVELY. 

✱EQUIVALENT MODEL OF"Z" PARAMETER:-

Fig(d) EQUIVALENT MODEL OF Z PARAMETER

   .....................Thank you 🙂👍...................