(Solved): One of the application for RLC circuit is signal filtering. Signal filtering is a process of filte ...

One of the application for RLC circuit is signal filtering. Signal filtering is a process of filtering or removing any unnecessary or undesired signal such as interferences. It is widely used in mobile networks to receive the desired wireless signal, which include \( 3 \mathrm{G}, 4 \mathrm{G} \) and the latest \( 5 \mathrm{G} \) signals. You can read more theoretical knowledge on the RLC filter at [1] and the latest mobile technologies at [2]. In this assignment, you have to design a band-pass filter as shown in Figure 1 to receive a mobile signal with a carrier frequency of \( 500 \mathrm{MHz} \). Assume that the mobile signal is modelled as a sinusoidal signal with a \( 5 \mathrm{~V} \) peak to peak value. The capacitor, \( C_{1} \) in the circuit is adjustable and the output of the circuit is measured across the load resistor, \( R_{\mathrm{b}} \). (i) What is the designed resonant frequency required by the band-pass filter as shown in Figure 1 ? (ii) Duplicate the circuit of Figure 1 using MultisimLive (refer to the Appendix 1) and plot the first graph of the output voltage, \( V_{0} \) based on the answer in part(i). Plot also the second graph of the output voltage by changing the capacitor to have a different value (i.e. \( 10 C_{1} \) or \( 0.1 C_{1} \) ) from the answer in part(i). Compare and briefly explain the differences among the plotted graphs and relate it back to the filtering/receiving action of the mobile signal. (iii) Based on the answer in part(i), replace the load resistor, \( R_{L} \) with any new resistance value (i.e. \( 1 \mathrm{k} \Omega \) or \( 100 \mathrm{k} \Omega \) ) and plot again the graph of the output voltage, \( V_{0} \) using MultisimLive (refer to the Appendix 1). Observe and briefly explain the changes of the output voltage as the load resistance is varied.