Practice previous years' questions for Electromagnetics, Antennas, Microwave Engineering, Digital Communication, Signals & Systems, Analog Electronics, VLSI, and Optical Communications.
Marking scheme: +3.00 positive, -0.75 negative (ICRB Standard).
A lossless transmission line having a characteristic impedance of $Z_0 = 50\ \Omega$ is terminated by an unknown load impedance $Z_L$. If the Voltage Standing Wave Ratio ($\text{VSWR}$) measured along the line is $s = 3.0$ and a voltage minimum occurs at the load terminals, what is the value of the load impedance $Z_L$?
A discrete-time linear time-invariant system has the system function:
$$H(z) = \frac{z}{z - 0.5} + \frac{z}{z - 2.0}$$For the system to be both stable and causal, what must be the Region of Convergence ($\text{ROC}$)?