2. Two – Port Network

 

A network contains active and passive elements connected in the form of a circuit.

Usually, a network has one pair of terminals for Input and other pair for the output. A pair of Input terminals of the network is called as Input port and the pair of the output terminals is called as the output port. Such a network is called as two port network. If the elements in the network are linear, the network is known as linear two port network. To understand the characteristics or to analyse a linear two port network, consider a black box as shown in figure 2.1. The 1, 1 terminals of the black box is known as input port and 2, 2 terminals is known as output port. 

                                                            

                                                 

                                                           

                 

                                                                   Fig. 2.1

                                                 

In this network V1, I1 are the Input voltage and current; and V2, I2 are the output voltage and current. Any pair of variables may be arbitrarily chosen as independent variables, and other variables (dependent variables) may be obtained as a function of independent variables that is dependents variables may assumed to be the functions of independent variables.