FUNDAMENTALS OF ANALOG COMMUNICATION

1. Define communication.

2. Define modulation.    

3. Why modulation is needed?

4. Define Amplitude Modulation (AM).

5. Write the AM wave expression.

6. What is carrier signal?

7. Define the term Modulation index or modulation co-efficient.

8. Write the expression for modulation index in terms v_maxof and v_min

9. Define AM envelope.

10. Define Percentage modulation or Depth of modulation.

11. Write the bandwidth of AM.

12. Draw the voltage spectrum of AM wave.

13. Draw the power spectrum of AM wave.

14. Write the relation between carrier power and total power. (or) Write the total power of modulated wave.

15. Write the advantages of AM.

16. Write the disadvantages of AM. What are the two major limitations of the standard form of amplitude modulation?

17. Write the applications of AM.

18. In AM system, the transmitter gives an output power of 5kw when modulated to a depth of 95%.  Calculate the carrier power.

19. The carrier amplitude after amplitude modulation varies between 4v and 1v .Calculate the depth of modulation.

20.  A transmitter radiates 9kW without modulation and 10.125kw after modulation. Determine the depth of modulation.

21.  If a 10kW amplitude modulated transmitter is modulated sinusoidally by a 50%. What is the total power delivered?  

22.  A carrier of 20MHz is amplitude modulated with a signal frequency of 3kHz and amplitude 5v. If the m_a=0.5,Sketch the spectra of the waveform.

23. If a modulated wave with an average voltage of 20v_pchanges in amplitude ±5v, determine the maximum and minimum envelope amplitudes and the modulation co-efficients.                                             

24. A carrier is frequency modulated with a sinusoidal signal of 2 kHz resulting in a maximum frequency deviation of 5 kHz. Find the bandwidth of the modulated signal.   

25. Calculate the BW of FM signal whose frequency deviation is 75 kHz and signal frequency is 2.5 kHz.                

26. State the significant usage of modulation index and also state why its value is restricted between 0 and 1.           

27. Justify why power is not a constant factor in AM modulation techniques.

28. Define angle modulation.

29. Write the classification of angle modulation.

30. Define frequency modulation (FM).

31.  Define phase modulation (PM).

32.  What is direct and indirect FM?

33.  Define modulation index in FM.

34.  Define frequency deviation.

35.  Define carrier swing.

36.  Define Percentage modulation

37. Define deviation ratio.

38. How the angle modulated waves are classified depends upon the modulation index value?

39. State Carson's rule.

40. What is actual bandwidth required for high-index FM? In FM, does the bandwidth directly related to the sidebands? If so justify. The required bandwidth of FM transmission depends upon the modulation index-Justify.    

41. What is the effect of modulation index on the bandwidth of FM?

42. Why angle modulated waves are more immune to effects of noise?

43. Write the advantage and disadvantage of FM compared to AM?

44. Compare AM and FM.

45. Difference between Narrowband FM and wideband FM.

46. Illustrate the relationship between frequency modulation and phase modulation.

47. A 107.6 MHz carrier is frequency modulated by a 7 kHz sine wave. The resultant FM signal has a frequency derivation of 50 kHz. Determine the modulation index of the FM wave.

48. A carrier of frequency 100 MHz is frequency modulated by a signal x(t)=20sin(200∏*10³t) .What is the bandwidth of the FM signal if the frequency sensitivity is 25 kHz per volt?

49. What is the bandwidth required for an FM wave in which the modulating frequency signal is 2 kHz and the maximum frequency deviation is 12 kHz? 

50. Draw the frequency spectrum of an FM wave for m_f=0.5.

51. Determine the bandwidth of wideband FM, given that carrier of 100MHz frequency modulates a signal of 5 kHz with 50 kHz as frequency deviation.

52. A 8 MHz carrier is frequency modulated by a sinusoidal signal of 1v amplitude and the frequency sensitivity is 100 Hz/v. Find the approximate bandwidth of the FM waveform if the modulating signal has a frequency of 10kHz.

53.  State the disadvantages of FM.         

54.  Obtain the bandwidth of FM signal c(t)=v cos[2*10⁷*∏t+8cos(1000*∏t)]