JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III ANALOG COMMUNICATIONS Previous Question Paper (November/December - 2017 - R13)
Note: This question paper contains two parts A and B. Part A is compulsory which carries 25 marks. Answer all questions in Part A. Part B consists of 5 Units. Answer any one full question from each unit. Each question carries 10 marks and may have a, b, c as sub questions.
Part A
What are the advantages of ring modulator?
Answer
The ring modulator provides a stable output with low distortion, produces a balanced output that suppresses the carrier signal, and allows for efficient switching due to the use of diodes.
What is the difference between coherence detection and noncoherent detection?
Answer
Coherent detection requires a local oscillator signal that is perfectly synchronized in both frequency and phase with the incoming carrier. Non-coherent detection does not require carrier synchronization, making it simpler and less expensive to implement, though it typically performs worse in terms of signal-to-noise ratio.
What are the advantages of SSB over DSB?
Answer
Sign in to view the complete answer paper.
What are the applications of VSB?
Answer
Sign in to view the complete answer paper.
Give the average power of an FM signal.
Answer
Sign in to view the complete answer paper.
What are the disadvantages of FM systems?
Answer
Sign in to view the complete answer paper.
Define Shot noise?
Answer
Sign in to view the complete answer paper.
What are the sources of Noise?
Answer
Sign in to view the complete answer paper.
Define Intermediate frequency?
Answer
Sign in to view the complete answer paper.
What are the advantages of PPM over PWM?
Answer
Sign in to view the complete answer paper.
Unit I
Explain the generation of AM signal using Switching Modulator.
Answer
Sign in to view the complete answer paper.
What is the effect of frequency and phase over error in demodulation of DSB-SC wave using synchronous detector.
Answer
Sign in to view the complete answer paper.
Explain about balanced modulator to generate DSB-SC signal.
Answer
Sign in to view the complete answer paper.
Discuss AM in detail in time and frequency domains. Derive the expression for power content of an AM signal.
Answer
Sign in to view the complete answer paper.
Unit II
Draw the block diagram for the generation of a VSB signal and explain the principle of operation.
Answer
Sign in to view the complete answer paper.
Compare AM with DSB-SC and SSB-SC.
Answer
Sign in to view the complete answer paper.
Explain the generation AM SSB Modulated waves using Phase discrimination method for generating.
Answer
Sign in to view the complete answer paper.
What are the Applications of different AM Systems? Explain any one.
Answer
Sign in to view the complete answer paper.
Unit III
Derive an expression for single tone FM wave and Wide band FM wave.
Answer
Sign in to view the complete answer paper.
With neat sketch explain the working principle of Zero crossing detector.
Answer
Sign in to view the complete answer paper.
Discuss threshold effect in angle modulation systems.
Answer
Sign in to view the complete answer paper.
Explain the Comparison of FM over AM.
Answer
Sign in to view the complete answer paper.
Unit IV
Discuss the noise performance in DSB-SC receiver in detail.
Answer
Sign in to view the complete answer paper.
Derive the noise figure for cascade stages.
Answer
Sign in to view the complete answer paper.
What is Narrowband Noise discuss the properties of the quadrature components of Narrowband Noise.
Answer
Sign in to view the complete answer paper.
With neat sketches explain the Pre-emphasis and de-emphasis.
Answer
Sign in to view the complete answer paper.
Unit V
What are the advantages of Superhetrodyne receiver over Tuned radio frequency receiver? Explain.
Answer
Sign in to view the complete answer paper.
Discuss the effect of aliasing due to under sampling.
Answer
Sign in to view the complete answer paper.
Differentiate between simple, delayed and amplify AGC and explain the function with the help of neat diagram.
Answer
Sign in to view the complete answer paper.
With neat sketch explain the TDM multiplexing and demultiplexing.
Answer
Sign in to view the complete answer paper.