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

Let $${w^4} = 16j$$. Which of the following cannot be a value of $$w$$?

Consider a system with input $$x(t)$$ and output $$y(t) = x({e^t})$$. The system is

Let $$m(t)$$ be a strictly band-limited signal with bandwidth B and energy E. Assuming $${\omega _0} = 10B$$, the energy in the signal $$m(t)\cos {\omega _0}t$$ is