LINGAYAS INSTITUTE OF MANAGEMENT & TECHNOLOGY MADALAVARI GUDEM, VIJAYAWADA. Second Semester 2011-12 Course Title: AC Assignment - II Unit -V: 1.Explain how S/N ratio is a figure of merit incase of SSB-SC receiver. 2.Explain the noise performance of large noise case in AM receivers. 3.Prove that the figure of merit of a DSB-SC system is 1. 4.Give the noise power density in SSB-SC. 5.What is threshold effect in Am. Unit-VI: 1. Draw the block diagram of an SSB - SC transmitter employing sideband suppression filter and explain. 2.Why are limiters and preemphasis filters used in FM radio. 3.Draw thw block diagram of AM transmitter. 4.Explain how FM waves are generated using Direct method 5.What is the advantage of Armstrong transmitter over direct FM transmitter. Unit-VII: 1.With the aid of the block diagram explain TRF receiver. 2.Explain the basic superheterodyne principle. 3.List out the advantages and disadvantages of TRF receiver. 4.Give the performance of FM receiver. 5.Describe the circuit of an FET amplitude limiter, and with the aid of the transfer characteristic explain the operation of the circuit. Unit-VIII: 1.Describe the synchronization procedure for PAM, PWM and PPM signals. 2. Discuss about the spectra of PWM and PDM signals. 3. Describe the generation and demodulation of PPM with the help of block diagram and hence discuss its spectral characteristics. 4. Define and distinguish between PTM and PAM schemes. Sketch and explain their waveform for a single tone sinusoidal input signal. 5. What is pulse width modulation? What other names does it have? How is it demodulated?