We continue to work with the full$-$bridge inverter circuit shown in Fig. $1.$ The inverter now operates as a pulse$-$width modulation $($PWM$)$ inverter. $($a$)$ Measurement of several signals of the PWM full$-$bridge inverter during one output cycle $(50$ Hz$)$ at nominal operation is given in the file "inverter signals.csv$".$ The sampling frequency of the measurement is $2$ MHz$.$ Using the measurement dataset, plot the waveform of the PWM inverter output voltage signal $($use the signal "PWMVoltage" from the dataset$).$ Use any $10$ cycles of switching period in the plot to have a clear graph. Also, plot the Fourier amplitude spectrum of the signal using the frequency range $50$ Hz $100$ kHz$.$ Compute the THD value of the signal. What can you say about the difference between the PWM voltage and the square$-$wave voltage in the previous question? $($b$)$ An LC low$-$pass filtering circuit as shown in Fig. $3$ was added to the output of the inverter circuit to filter out the higher$-$order harmonics. Using the measurement dataset, plot the waveform of the filtered output voltage of the inverter $($use the signal "OutputVoltage" from the dataset$).$ Plot the Fourier amplitude spectrum of the filtered output voltage using the frequency range $50$ Hz$2$ kHz$.$ Compute the THD value of the plotted voltage signal. What can you say about the difference between the filtered PWM voltage and the square$-$wave voltage in the previous question?