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INSTRUCTIONS
(1) Assume appropriate data and state your reasons
(2) Marks are given to the right of every question
(3) Draw neat diagrams wherever necessary

Solve any one question from Q.1(a,b) &Q.2(a,b)
1(a) Distinguish clearly between Baseband communication and carrier communication.
6 M
1(b) Sketch AM signal for the given periodic triangle signal m(t) corresponding to:
i) m= 0.5
ii) m= 1
iii) m=2
m=∞?
!mage
6 M

2(a) Explain the following performance characteristics of receiver with response curve?
i) Sensitivity
ii) Selectivity
iii) Fidelity
iv) Image frequency rejection.
6 M
2(b) A receiver tunes signal from 3 Mhz to 30MHz with an IF of 455 kHz. Find the frequency tuning ranges and capacitor tuning ranges for the oscillator section and RF section.
6 M

Solve any one question from Q.3(a,b) &Q.4(a,b)
3(a) Give comparison between FM and PM?
6 M
3(b) Describe Armstrong method for Indirect FM generation of wideband angle modulation signals.
6 M

4(a) Discuss principle working of FM detection. Briefly explain any one FM detector method.
6 M
4(b) Justify "Ration detector acts as Detector as well as limiter"?
6 M

Solve any one question from Q.5(a,b) &Q.6(a,b)
5(a) Draw equivalent sources for thermal noise (voltage and current) and derive the expression for rms noise volatage and rms noise current.
6 M
5(b) Three resistors of 33kΩ, 56kΩ and 75kΩ are at 310.5° K temperature. For a B. W. Of the 100 kHz. Calculate thermal noise voltage generated by:
i) Each resistor
ii) Three resistor in series
iii) Resistor combination as shown?
!mage
7 M

6(a) Derive expression for Friss formula for noise factor of amplifier in cascade.
7 M
6(b) A mixer stage has noise figure of 28dB, and these is preceded by an amplifier that has noise figure of 7dB and an available power gain of 20dB. Calculate the overall noise figure referred to thre input.
6 M

Solve any one question from Q.7(a,b) &Q.8(a,b)
7(a) State and prove sampling theorem for band limited signal.
7 M
7(b) Compare PAM, PWM and PPM.
6 M

8(a) Describe with suitable block diagram pulse code modulation.
7 M
8(b) What is meant by "Aperture Effect"? How can it be reduced?
6 M

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