CHAPTER FOUR

Multiport Circuit Parameters and Transmission Lines

4.1 VOLTAGE–CURRENT TWO-PORT PARAMETERS

A linear n-port network is completely characterized by n independent excitation variables and n dependent response variables. These variables are the terminal voltages and currents. There are four ways of arranging these independent and dependent variables for a two-port circuit that are particularly useful, especially when considering feedback circuits. They are the impedance parameters (z matrix), admittance parameters (y matrix), hybrid parameters (h matrix), and the inverse hybrid parameters (g matrix). These four sets of parameters are defined as:

(4.1)

(4.2)

(4.3)

(4.4)

Two networks connected in series (Fig. 4.1) can be combined by simply adding the z parameters of each network together. This configuration is called the series–series connection. In the shunt–shunt configuration shown in Fig. 4.2, the two circuits can be combined by adding their y matrices together. In the series–shunt configuration (Fig. 4.3), the composite matrix for the combination ...