UNIT I: ANTENNA FUNDAMENTALS
PART – A
1. Define an antenna.
2. What is meant by radiation pattern?
3. Define Radiation intensity
4. Define Beam efficiency
5. Define Directivity
6. What are the different types of aperture?
7. Define different types of aperture
8. Define Aperture efficiency
9. What is meant by effective height?
10. What are the field zone?
11.What is meant by Polarization?
12. What is meant by front to back ratio?
13. Define antenna efficiency
14. What is radiation resistance ?
15. What is meant by antenna beamwidth?
16. What is meant by reciprocity theorem?
17.What is meant by isotropic radiator?
18. Define gain
19. Define self impedance
20. Define mutual impedance
21. What is meant by cross field.?
22. Define axial ratio
23. What is meant by Beam Area.?
24. What is duality of antenna?
25. What is point source?
26. What is meant by array?
27. What is meant by uniform linear array?
28.What are the types of array?
29.What is Broad side array?
30.Define End fire array
31. What is collinear array?
32. What is the condition on phase for the end fire array with increased directivity.?
33. Define array factor.
34. Define beam width of major lobe?
35. List out the expression of beam width for broad side array and end fire array.
PART – B
1. With neat sketch, explain the operation of helical antenna? (16)
2. Obtain the expression for the field and the radiation pattern produced by a 2 element array of
infinitesimal with distance of separation 1/2 and currents of unequal magnitude and phase shift
180 degree? (16)
3. Derive the expression for far field components of a small loop antenna. (16)
4. Derive the expression for electric field of a broadside array of n sources and also find the
maximum direction minimum direction and half power point direction? (16)
5. Design a 4 element broadside array of 1/2 spacing between elements, the pattern is to be
optimum with a side lobe level 19.1 db. Find main lobe maximum? (16)
6. Explain pattern multiplication (8)
7. Derive the expression for electric field of an end fire of n sources and also find the maximum
direction minimum direction and half power point direction? (16)
8. Write short notes a radiation resistance? (8)
9. Calculate the maximum effective aperture of a 1/2 antenna? (8)
10. Derive the maxima directions, minima directions, and half power point direction for an array
of two point sources with equal amplitude and opposite phase? (16)
11. Explain the various types of amplitude distributions in details? (16)