Kannur University 2009 B.Tech Sixth Semester Engineering (Improvement/Supplementary) , EC 2K 602 : RADIATION AND PROPAGATION - Question Paper

6th Semester B.Tech. Engineering Degree (Improvement/Supplementary) Examination, May 2009


EC 2K 602 : RADIATION AND PROPAGATION




Time: three Hours Max. Marks: 100


Instructions : ans all questions.


PART- A

1. what is the practical elementary dipole ? Derive the expression for radiation resistance of a short dipole and monopole of length l/2 [Marks 5]

2. Derive an expression for radiation resistance of a current element. [Marks 5]

3. discuss the design procedure for binominal array. [Marks 5]

4. discuss the array factor for a uniform line array. [Marks 5]

5. With a neat radiation trend discuss a travelling wave antenna. [Marks 5]

6. discuss frequency independent antennas. [Marks 5]

7. explain surface wave with necessary expressions. [Marks 5]

8. discuss the principle of plasma oscillations. [Marks 5]


PART- B


9.a) i) Derive an expression for E and H in case of a quarter wave monopole. [Marks 8]

ii) discuss briefly various kinds of antenna field zones with the help of a diagram. [Marks 7]

OR

b) discuss the terms :

i) Radiation trend [Marks 3]

ii) Directive gain [Marks 3]

iii) Power gain [Marks 3]

iV) Beam width [Marks 3]

v) Bandwidth with reference to an antenna. [Marks 3]

10.a) i) discuss two-element array of isotropic point sources. [Marks 7]

ii) discuss amplitude and phase charecterstics of a 2 element array of isotropic point sources. [Marks 8]

OR

b) discuss the principle of trend multiplication with example. [Marks 15]

11.a) i) discuss the methodes of feeding a long wire antenna. [Marks 7]

ii) With a necessary diagrams, discuss methods of excitations of the folded dipole antenna. [Marks 8]

OR

b) i) With a neat sketch, discuss Yagi Uda antenna. [Marks 8]

ii) Write a note on horn antenna. [Marks 7]

12.a) i) discuss replaced index curves and Duct propagation. [Marks 7]

ii) discuss refelection and refraction of waves by the ionosphere with the help of digram. [Marks 8]

OR

b) i) discuss wave tilt of a surface wave. [Marks 7]

ii) discuss the subsequent : [Marks 8]

I) Critical frequency

II) Virtual height.

Earning:   Approval pending.