Thursday, June 27, 2013

3RD YEAR SEMESTER 1 SUPPLEMENTARY JUNE 2010 JNTU B.TECH ENGINEERING QUESTION PAPER - ANTENNAS AND WAVE PROPAGATION

Code No:  RR310402                     RR           Set No.   2

 

 

III  B.Tech I Semester Supplementary Examinations,June 2010

ANTENNAS AND WAVE PROPAGATION

Common to Electronics And Telematics, Electronics And Communication

Engineering

Time: 3 hours                                                                                  Max Marks:  80

Answer any FIVE Questions

All  Questions carry equal marks

? ? ? ? ?

 

 

1.   (a)  List out the frequency ranges of operation  and applications  of i. Loop antennas

ii. Helical antennas

iii. Lens antennas.

 

(b)  Derive the EMF equation  for a small loop antenna.                               [12+4]

 

2.   (a)  How can a unidirectional  pattern be obtained  in an end fire array?   Explain  in detail.

 

(b)  Draw the  radiation  pattern of 8 isotropic  elements  fed in phase,  spaced λ/2

apart  with the principle of pattern multiplication.                                     [8+8]

 

3.   (a)  Distinguish between the terms:  effective length and effective area and deduce

the relation  between them.

 

(b)  How is the radiation  pattern of an antenna specified?

 

(c)  Find  the  directivity  and  HPBW  of an antenna having  a unidirectional  cosθ

radiation  intensity  pattern.                                                                   [6+4+6]

 

4. Write  notes on

 

(a)  M curves and their characteristics.

 

(b)  Troposcatter Propagation of electromagnetic  waves.                                [6+10]

 

5. Both very long waves and short waves can be used for world wide radio communica- tion.  Give general account of the propagation  phenomena and frequencies involved in the two cases and discuss the advantages  and disadvantages of the two systems. [16]

 

6.   (a)  Distinguish  between electrostatic  field term,  near and far zone field terms for electric and magnetic  fields due to a short oscillating current element.

 

(b)  Taking expression for radiation  fields, compute power radiated  by the current element.

 

(c)  Define a Hertzian  dipole and an Oscillating  current element and distinguish between them.  Sketch the radiation  pattern for a vertical Hertzian  dipole, in both principal  planes.                                                                                [6+4+6]

 

 

 

 

1


Code No:  RR310402                     RR           Set No.   2

 

 

7.   (a)  What  is an  Optimum  Horn?   Sketch  and  explain  the  characteristics of an optimal  pyramidal  horn, along with the dimensional relations.

 

(b)  List out  the  frequency ranges of usage and applications  of different  lens an- tennas.                                                                                                             [10+6]

 

8.   (a)  Compare  the requirements  and radiation  characteristics of resonant and non- resonant radiators.

 

(b)  Determine  the  lengths  and  spacing  requirements  for a 3-element  Yagi -Uda antenna array  at 500 MHz, and explain its characteristics.                     [6+10]

 

 

? ? ? ? ?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2


Code No:  RR310402                     RR           Set No.   4

 

 

III  B.Tech I Semester Supplementary Examinations,June 2010

ANTENNAS AND WAVE PROPAGATION

Common to Electronics And Telematics, Electronics And Communication

Engineering

Time: 3 hours                                                                                  Max Marks:  80

Answer any FIVE Questions

All  Questions carry equal marks

? ? ? ? ?

 

 

1.   (a)  How can a unidirectional  pattern be is obtained  in an end fire array?   Explain  in

detail.

 

(b)  Draw the  radiation  pattern of 8 isotropic  elements  fed in phase,  spaced λ/2 apart  with the principle of pattern multiplication.                                     [8+8]

 

2. Write  notes on

 

(a)  M curves and their characteristics.

 

(b)  Troposcatter Propagation of electromagnetic  waves.                                [6+10]

 

3.   (a)  What  is an  Optimum  Horn?   Sketch  and  explain  the  characteristics of an optimal  pyramidal  horn, along with the dimensional relations.

(b)  List out  the  frequency ranges of usage and applications  of different  lens an-

tennas.                                                                                                             [10+6]

 

4.   (a)  Compare  the requirements  and radiation  characteristics of resonant and non- resonant radiators?

(b)  Determine  the  lengths  and  spacing  requirements  for a 3-element  Yagi -Uda antenna array  at 500 MHz, and explain its characteristics.                    [6+10]

 

5.   (a)  List out the frequency ranges of operation  and applications  of

 

i. Loop antennas

ii. Helical antennas iii. Lens antennas.

(b)  Derive the EMF equation  for a small loop antenna.                               [12+4]

 

6. Both very long waves and short waves can be used for world wide radio communica- tion.  Give general account of the propagation  phenomena and frequencies involved in the two cases and discuss the advantages  and disadvantages of the two systems. [16]

 

7.   (a)  Distinguish between the terms:  effective length and effective area and deduce the relation  between them.

(b)  How is the radiation  pattern of an antenna specified?

 

(c)  Find  the  directivity  and  HPBW  of an antenna having  a unidirectional  cosθ

radiation  intensity  pattern.                                                                   [6+4+6]

 

 

3


Code No:  RR310402                     RR           Set No.   4

 

 

8.   (a)  Distinguish between electrostatic  field term,  near and far zone field terms for electric and magnetic fields due to a short oscillating current element.

 

(b)  Taking expression for radiation  fields, compute power radiated by the current element.

 

(c)  Define a Hertzian  dipole and an Oscillating  current element and distinguish between them.  Sketch the radiation  pattern for a vertical  Hertzian  dipole, in both principal  planes.                                                                                [6+4+6]

 

 

? ? ? ? ?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4


Code No:  RR310402                     RR           Set No.   1

 

 

III  B.Tech I Semester Supplementary Examinations,June 2010

ANTENNAS AND WAVE PROPAGATION

Common to Electronics And Telematics, Electronics And Communication

Engineering

Time: 3 hours                                                                                  Max Marks:  80

Answer any FIVE Questions

All  Questions carry equal marks

? ? ? ? ?

 

 

1.   (a)  List out the frequency ranges of operation  and applications  of

 

i. Loop antennas

ii. Helical antennas iii. Lens antennas.

(b)  Derive the EMF equation  for a small loop antenna.                               [12+4]

 

2.   (a)  Compare  the requirements  and radiation  characteristics of resonant and non- resonant radiators?

(b)  Determine  the  lengths  and  spacing  requirements  for a 3-element  Yagi -Uda

antenna array  at 500 MHz, and explain its characteristics.                     [6+10]

 

3.   (a)  What  is an  Optimum  Horn?   Sketch  and  explain  the  characteristics of an

optimal  pyramidal  horn, along with the dimensional relations.

 

(b)  List out  the  frequency ranges of usage and applications  of different lens an- tennas.                                                                                                             [10+6]

 

4. Write  notes on

 

(a)  M curves and their characteristics.

 

(b)  Troposcatter Propagation of electromagnetic  waves.                                [6+10]

 

5.   (a)  How can unidirectional  pattern be obtained  in an end fire array?   Explain  in

detail?

 

(b)  Draw the  radiation  pattern of 8 isotropic  elements  fed in phase,  spaced λ/2 apart  with the principle of pattern multiplication.                                   [8+8]

 

6.   (a)  Distinguish  between electrostatic  field term,  near and far zone field terms for electric and magnetic  fields due to a short oscillating current element.

(b)  Taking expression for radiation  fields, compute power radiated  by the current

element.

 

(c)  Define a Hertzian  dipole and an Oscillating  current element and distinguish between them.  Sketch the radiation  pattern for a vertical Hertzian  dipole, in both principal  planes.                                                                                [6+4+6]

 

7.   (a)  Distinguish between the terms:  effective length and effective area and deduce the relation  between them.

 

 

5


Code No:  RR310402                     RR           Set No.   1

 

 

(b)  How is the radiation  pattern of an antenna specified?

 

(c)  Find  the  directivity  and  HPBW  of an antenna having  a unidirectional  cosθ

radiation  intensity  pattern.                                                                   [6+4+6]

 

8. Both very long waves and short waves can be used for world wide radio communica- tion.  Give general account of the propagation  phenomena and frequencies involved in the two cases and discuss the advantages  and disadvantages of the two systems. [16]

 

 

? ? ? ? ?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

6


Code No:  RR310402                     RR           Set No.   3

 

 

III  B.Tech I Semester Supplementary Examinations,June 2010

ANTENNAS AND WAVE PROPAGATION

Common to Electronics And Telematics, Electronics And Communication

Engineering

Time: 3 hours                                                                                  Max Marks:  80

Answer any FIVE Questions

All  Questions carry equal marks

? ? ? ? ?

 

 

1.   (a)  Distinguish between the terms:  effective length and effective area and deduce the relation  between them.

 

(b)  How is the radiation  pattern of an antenna specified?

 

(c)  Find  the  directivity  and  HPBW  of an antenna having  a unidirectional  cosθ

radiation  intensity  pattern.                                                                 [6+4+6]

 

2.   (a)  List out the frequency ranges of operation  and applications  of i. Loop antennas

ii. Helical antennas

iii. Lens antennas.

 

(b)  Derive the EMF equation  for a small loop antenna.                               [12+4]

 

3.   (a)  What  is an  Optimum  Horn?   Sketch  and  explain  the  characteristics of an

optimal  pyramidal  horn, along with the dimensional relations.

 

(b)  List out  the  frequency ranges of usage and applications  of different lens an- tennas.                                                                                                             [10+6]

 

4. Write  notes on

 

(a)  M curves and their characteristics.

 

(b)  Troposcatter Propagation of electromagnetic  waves.                                [6+10]

 

5.   (a)  Distinguish  between electrostatic  field term,  near and far zone field terms for

electric and magnetic  fields due to a short oscillating current element.

 

(b)  Taking expression for radiation  fields, compute power radiated  by the current

element.

 

(c)  Define a Hertzian  dipole and an Oscillating  current element and distinguish between them.  Sketch the radiation  pattern for a vertical Hertzian  dipole, in both principal  planes.                                                                                [6+4+6]

 

6.   (a)  Compare  the requirements  and radiation  characteristics of resonant and non- resonant radiators?

 

(b)  Determine  the  lengths  and  spacing  requirements  for a 3-element Yagi -Uda antenna array  at 500 MHz, and explain its characteristics.                     [6+10]

 

 

 

7


Code No:  RR310402                     RR           Set No.   3

 

 

7.   (a)  How can unidirectional  pattern be obtained  in an end fire array?   Explain  in detail?

 

(b)  Draw the  radiation  pattern of 8 isotropic  elements  fed in phase,  spaced λ/2 apart  with the principle of pattern multiplication.                                     [8+8]

 

8. Both very long waves and short waves can be used for world wide radio communica- tion.  Give general account of the propagation  phenomena and frequencies involved in the two cases and discuss the advantages  and disadvantages of the two systems. [16]

 

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