The S-parameters of a two port network is given as
$$[S] = \left[ {\matrix{ {{S_{11}}} & {{S_{12}}} \cr {{S_{21}}} & {{S_{22}}} \cr } } \right]$$
with reference to $${Z_0}$$. Two lossless transmission line sections of electrical lengths $${\theta _1} = \beta {l_1}$$ and $${\theta _2} = \beta {l_2}$$ are added to the input and output ports for measurement purposes, respectively. The S-parameters $$[S']$$ of the resultant two port network is
A linear 2-port network is shown in Fig. (a). An ideal DC voltage source of 10 V is connected across Port 1. A variable resistance R is connected across Port 2. As R is varied, the measured voltage and current at Port 2 is shown in Fig. (b) as a V2 versus $$-$$I2 plot. Note that for V2 = 5 V, I2 = 0 mA, and for V2 = 4 V, I2 = $$-$$4 mA. When the variable resistance R at Port 2 is replaced by the load shown in Fig. (c), the current I2 is ________ mA (rounded off to one decimal place).
