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VALLIAMMAI ENGINEERING COLLEGE

SRM Nagar, Kattankulathur – 603 203

DEPARTMENT OF

ELECTRONICS AND COMMUNICATION ENGINEERING

QUESTION BANK

VI SEMESTER

EC 6602 – Antenna and Wave Propagation

Regulation – 2013

Academic Year 2017 – 18 ( Even)

Prepared by

Ms. T.S.Sheriba, Assistant Professor (SG)/ECE

Mr.T.V.Sudhir, Assistant Professor(OG) /ECE

Mr. A.G.Murali Krishna, Assistant Professor(OG)/ECE

VALLIAMMAI ENGINEERING COLLEGE SRM Nagar, Kattankulathur – 603 203.

DEPARTMENT OF ELECTRONICS AND COMMUNICATION

ENGINEERING QUESTION BANK

SUBJECT : EC6602 – ANTENNA AND WAVE PROPAGATION

SEM / YEAR: VI / III

Unit I - FUNDAMENTALS OF RADIATION

Definition of antenna Parameters - Gain, Directivity, Effective aperture, Radiation Resistance,

Bandwidth, Beamwidth, Input Impedance. Matching-Baluns, Polarization mismatch, Antenna noise

temperature, Radiation from oscillating dipole, Half wave dipole. Folded dipole, Yagi array

PART A

Q.No Questions BT Competence

1. List the antenna parameters. BTL 1 Remembering

2. Recall Radio Antenna. BTL 1 Remembering

3. Draw the 3D pattern of a directional antenna with maximum in z- direction

at θ = 0˚.

BTL 1 Remembering

4. Define the term Half Power Beam Width. BTL 1 Remembering

5. What is an elementary dipole and how does it differ from the infinitesimal

dipole?

BTL 1 Remembering

6. Review the types of an antenna. BTL 1 Remembering

7. Relate the Gain and Directivity of an antenna through proper expression. BTL 2 Understanding

8. Discuss about retarded potential in antenna. BTL 2 Understanding

9. Summarize the types of Baluns and its applications. BTL 2 Understanding

10. A radio link has a 15W transmitter connected to an antenna of 2.5 m2

effective aperture at 5 GHz. The receiving antenna has an effective

aperture of 0.5 m2 and is located at a 15 km Line-of-sight distance from

the transmitting antenna. Assuming lossless, matched antennas, estimate

the power delivered to receiver.

BTL 2

Understanding

11. Solve the HPBW for an antenna with a field pattern given by

Eφ=Cos2φ for 0˚≤ φ ≤90˚

BTL 3 Applying

12. Calculate the effective length of the element considering the voltage

induced by the application of an electric field of strength 2 volts / meter is 0.7 volt.

BTL 3 Applying

13. Sketch the structure of Yagi Uda Array for a frequency of 200 MHz. BTL 3 Applying

14. Distinguish between power gain and directive gain. BTL 4 Analyzing

15. Examine the total radiated power if the radial component of the radiated power density of an antenna is given by Wrad = Wrâr = ârAosinθ / r2 (W/m2)

where Ao is the peak value of the power density, θ is the usual spherical coordinate and âr is the radial unit vector.

BTL 4 Analyzing

16. Analyze the θ and φ patterns in an antenna radiation pattern and mention what does dB and dBi denotes.

BTL 4 Analyzing

17. Evaluate the efficiency and directivity (in dB) if the radiation resistance of an antenna is 65 ohms and loss resistance is 10 Ohms.

BTL 5 Evaluating

18. Deduce the equation for “directivity from pattern”. Modify the above equation to get the equation for “directivity from aperture”.

BTL 5 Evaluating

19. Design a λ\2 dipole antenna to resonate at a frequency of 5GHz. BTL 6 Creating

20. Devise an appropriate equation to find the intrinsic impedance of a dipole. BTL 6 Creating

Part B

1. Define and explain in detail the following antenna parameters. (a) Antenna noise temperature (b) Bandwidth (c) Input Impedance (d) Effective

aperture. (13)

BTL 1 Remembering

2. Describe the structure with diagram and operation principle of Yagi-Uda

array in detail. (13)

BTL 1 Remembering

3. Select a proper method to match the impedance of the antenna and explain in detail. Explain the impedance matching using Baluns. (13)

BTL 1 Remembering

4.

Write short notes on (13) (i)Vector Potential (ii)Polarization (iii)Retarded Potential (iv)Radiation Pattern

BTL 1 Remembering

5. Discuss in detail about the radiation from a small oscillating current

element with the required E and H field quantities and diagrams. (13)

BTL 2 Understanding

6. Explain the structure of a folded dipole antenna and find the radiation resistance and the admittance of the folded dipole. Relate the surrounding temperature factors associated with the antenna temperature , through proper explanation and expression. (13)

BTL 2 Understanding

7. Illustrate the radiated fields of a center fed λ/2 dipole antenna with an appropriate expressions. Sketch the radiation pattern. (13)

BTL 2 Understanding

8. Demonstrate the principle of radiation from an oscillating electric dipole.

Derive the near field and far field expressions. (13)

BTL 3 Applying

9. Show that the directivity of an antenna depends on the power radiated. Using the expression obtained for directivity determine the maximum directivity of the antenna for an infinitesimal linear dipole of length l<< λ for which the radial component of the power density is Wav = Wr = Ao (sin2 θ / r2) (W/m2) (13)

BTL 3

Applying

10. Derive the expression for the field quantities radiated from a λ/2 dipole and prove that the radiation resistance to be 73 Ω . (13)

BTL 4 Analyzing

11. The power radiated by a lossless antenna is 10 Watts. The directional characteristics of the antenna are represented by the radiation intensity of

U = Bo cos3θ(ω /Sr) for 0 < θ ≤ π/2 and 0 < φ ≤ 2π

Find the maximum power density at a distance of 1000 m, assuming far field distance. Specify the angle where this occur and find the directivity

and half power beamwidth of the antenna. (13)

BTL 4 Analyzing

12. Analyze the electric and magnetic field components of a finite length dipole antenna and show its current distribution with respect to its length

in terms of the wavelength. (13)

BTL 4 Analyzing

13. Justify the statements “Directivity is equal to the number of point sources

in the sky that the antenna can resolve” and “Directivity is directly proportional to the antenna effective aperture , Ae ” . (13)

BTL 5

Evaluating

14. Design the field equations for a Hertzian dipole to produce the purely

resistive intrinsic impedance. (13)

BTL 6 Creating

PART-C

1 Explain and conclude the terms “Radiation Resistance”, “gain”

”directivity”, “effective aperture” and “polarization” of an antenna (15)

BTL 5 Evaluating

2 Evaluate an expression for the power radiated by the current element and

calculate the radiation resistance (15)

BTL 5 Evaluating

3 Develop Hertizian dipoles.Predict the electric and magnetic field

quantities of infinitesimal and radiation pattern (15)

BTL 6 Creating

4 (i) Design the radiation resistance of an oscillating electric dipole (8)

(ii)Discuss and elaborate the polarization and its significance in antenna

analysis (7)

BTL 6 Creating

UNIT II APERTURE AND SLOT ANTENNAS

Radiation from rectangular aperture, Uniform and Tapered aperture, Horn antenna, Reflector

antenna, Aperture blockage, Feeding structures, slot antennas, Microstrip antennas-Radiation

mechanism, applications, Numeric tool for antenna analysis.

PART A

Q.No Questions BTL Competence

1. Discuss about the features of the pyramidal horn antenna. BTL 6 Creating

2. Determine the beam width and directivity of a pyramidal horn with

aperture dimensions of 12 x 6 cm, operating at a frequency of 10

GHz.

BTL 5 Evaluating

3. List the merits and applications of offset feed reflector antenna. BTL 4 Analyzing

4. Solve the diameter of aperture of a parabolic antenna to produce a

null beam width of 10ᵒ at 3GHz.

BTL 3 Applying

5. How the aperture blockage can be prevented in reflector antenna? BTL 1 Remembering

6. What are the advantages of Cassegrain feed? BTL 1 Remembering

7. Classify the different feed structures used for parabolic reflector. BTL 4 Analyzing

8. Compare Parabolic and Corner Reflector Antennas. BTL 2 Understanding

9. Draw and explain the different types of horn antennas. BTL 5 Evaluating

10. Examine the word ‘antenna tapering’. BTL 4 Analyzing

11. Define aperture blockage. BTL 1 Remembering

12. Relate the field equivalence principle with aperture antennas. BTL 1 Remembering

13. Name some numerical tools that can be used to analyze an antenna. BTL 1 Remembering

14. Recall the definition of FNBW and HPBW of aperture antenna. BTL 1 Remembering

15. Outline the applications of microstrip antenna. BTL 2 Understanding

16. Illustrate any four CAD tools & their features for antenna analysis. BTL 2 Understanding

17. On what principle slot antenna works? Explain the principle. BTL 2 Understanding

18. Make use of the design equations design a microstrip patch antenna at an operating frequency of 6 GHz.

BTL 3 Applying

19. Identify the limitations of a microstrip patch antenna. BTL 3 Applying

20. Elaborate the Huygens principle for Aperture antennas. BTL 6 Creating

PART – B

1. Describe rectangular apertures and derive expressions for its

uniform distribution on an infinite ground plane and space. (13)

BTL 1 Remembering

2. (i) A rectangular aperture with a constant field distribution with

a=4λ and b=3λ, is mounted on an infinite ground plane. Find the (a)FNBW and HPBW in E-plane (b) Directivity. (8)

(ii) Write short notes on the beamwidth and directivity of rectangular apertures. (5)

BTL 1 Remembering

3. Enumerate the radiation pattern and fields on the axis of an E-

plane and H-plane Sectoral horns. (13)

BTL 1 Remembering

4. (i) Point out the principle of operation of a rectangular horn antenna

with neat sketch. (7)

(ii) Examine the salient features of Flat and Corner reflector

antennas (6)

BTL 4 Analyzing

5. (i) Calculate the antenna gain and effective aperture of the reflector

antenna that has a 0.5 deg HPBW at a frequency of 8.2 GHz. Assume an efficiency constant = 0.6. (9)

(ii) A spherical reflector has a 10 feet diameter. If at 11.2 GHz the maximum allowable phase error is λ/16. Find the maximum

permissible aperture. (4)

BTL 3 Applying

6. (i) Explain how a parabolic antenna gives a highly directional pattern. (7)

(ii) Interpret the significance of f/D ratio of a parabolic reflector

(6)

BTL 2 Understanding

7. (i) Justify in detail about the tapering in antennas. (5)

(ii)A pyramidal horn antenna having aperture dimensions of a = 5.2 cm and b = 3.8 cm is used at a frequency of 10GHz. Determine its

gain and HPBW. (8)

BTL 5 Evaluating

8. (i) Identify the importance of Babinet’s principle on

complementary antennas. (7)

(ii) Draw different techniques used to feed the slot antenna. (6)

BTL 1 Remembering

9. (i) Outline the numerical techniques useful for the analysis of

antenna. Explain one of them in detail. (4) (ii) Summarize various feeding techniques for the rectangular

patch antenna with neat diagrams. (9)

BTL 2 Understanding

10. Illustrate the aperture blockage and explain how it can be

overcome by the offset feed. What are the advantages of cassegrain

feed? (13)

BTL 2 Understanding

11. With necessary sketches, illustrate the radiation mechanism of a microstrip patch antenna. (13)

BTL 3 Applying

12. Research the different feed mechanism used for parabolic reflector

antennas. (13)

BTL 4 Analyzing

13. Evaluate the radiation mechanism of Horn antenna with diagram.

Draw the different types of Horn structures. (13)

BTL 4 Analyzing

14. (i) In detail, develop the various methods of feeding a slot antenna.

(7) (ii) Formulate the Uniform aperture distribution on an infinite

ground plane for a circular aperture. (6)

BTL 6 Creating

PART-C

1 (i) A pyramidal horn antenna with the aperture length of 10λ cm is

fed by a rectangular waveguide in TE10 mode. Evaluate the design

parameters of the antenna operating at 2.5 GHz. (8)

(ii)Compare the slot and dipole antenna (7)

BTL 5 Evaluating

2 Justify the radiation mechanism of horn antenna with diagram.

Draw the different types of horn antenna (15)

BTL 5 Evaluating

3 Compile notes on (15)

1.Slot antenna

2.Reflector antenna

BTL 6 Creating

4 (i) Solve how a paraboloidal antenna gives a highly directional

pattern. (8)

(ii) Elaborate in detail about the feeding structure of parabolic

reflector antenna (7)

BTL 6 Creating

UNIT III ANTENNA ARRAYS

N element linear array, Pattern multiplication, Broadside and End fire array – Concept of Phased

arrays, Adaptive array, Basic principle of antenna Synthesis-Binomial array.

PART A

Q.No Questions BT

Competence

1. What is meant by grating lobe? Mention the significance of side lobe level.

BTL 1 Remembering

2. Define array factor. BTL 1 Remembering

3. Write about pattern multiplication and its advantages. BTL 1 Remembering

4. Recall the features of the adaptive array and where it is employed? BTL 1 Remembering

5. Draw the radiation pattern of an isotropic point sources of same

amplitude and opposite phase that are λ/2 apart along X-axis symmetric with respect to the origin.

BTL 1 Remembering

6. How to eliminate minor lobes? BTL 1 Remembering

7. Interpret the meaning of linear array and point source. BTL 2 Understanding

8. Summarize the advantages of linear array antenna. BTL 2 Understanding

9. Draw the radiation pattern for broad side and end fire array. BTL 2 Understanding

10. Enumerate the basic principle of antenna synthesis. BTL 2 Understanding

11. Show the conditions to obtain end fire array antenna. BTL 3 Applying

12. Identify the feed networks used in a phased array antenna . BTL 3 Applying

13. Illustrate the meaning and need for the binomial array. BTL 3 Applying

14. Find the directivity of broadside forms of arrays when a uniform linear

array contains 50 isotropic radiation with an inter element spacing of λ/2.

BTL 4 Analyzing

15. Classify antenna arrays. BTL 4 Analyzing

16. Explore the need for phase shifter in phased array antennas. BTL 4 Analyzing

17. Differentiate Binomial and Chebyshev distributions. BTL 5 Evaluating

18. Compare end fire and broad side array. BTL 5 Evaluating

19. A linear end fire, uniform array of 10 elements has a separation of λ/4 between elements. Formulate the directivity of an array.

BTL 6 Creating

20. Devise the relative excitation levels of a binomial array of 2 and 3

elements.

BTL 6 Creating

PART – B

1. Enumerate the expression for steering vector of phased array antenna

and explain its significance. Give an account of beamforming

networks for phased array antenna. (13)

BTL 1 Remembering

2. Obtain the expression for the field and the radiation pattern produced

by a N element array of infinitesimal with distance of separation λ/ 2

and currents of unequal magnitude and phase shift 180 degree. (13)

BTL 1

Remembering

3. (i)Quote and derive the expression for field pattern of broad side array of N point sources. (7)

(ii)A linear broadside array consists of 4 equal isotropic in-phase point sources with λ/3 spacing. Identify the directivity and beamwidth.(6)

BTL 1

Remembering

4. For a 2 element linear antenna array separated by a distance d = 3 λ/4 ,

derive the field quantities and draw its radiation pattern for the phase

difference of 45o. (13)

BTL 1 Remembering

5. Review how does the directivity of an array represent the figure of

merit on the operation of the system? Derive expressions for the

directivity of broadside array and end fire array. (13)

BTL 2 Understanding

6. (i) Research the radiation mechanisms of broad side antenna array and

End fire antenna array with neat sketches. (7)

(ii) What is binomial array? Draw the pattern of 10 element binomial array with spacing between the elements of 3λ/4 and λ/2. (6)

BTL 2

Understanding

7. Discuss and derive the expressions for directivity of the following N

element linear array antennas. (i) Broad side array (ii) End fire array

(iii) Phased array(iv) Tapered array (13)

BTL 2 Understanding

8. (i) Show the expression for the field produced by linear array and

deduce it for an end fire array. (7) (ii) Express the characteristics of broad side and end fire array. (6)

BTL 3

Applying

9. (i)Illustrate about the method of pattern multiplication. (6)

(ii)Solve the expression for directions of pattern minima, pattern maxima, BWFN due to broad side array. (7)

BTL 3

Applying

10. (i) Find the array length , number of elements when elements in an

array are spaced at λ/2 and null-to-null beamwidth for an array of

dipoles of λ/2 length in end fire mode which produces a power gain

of 28. (6)

(ii) Examine how analog and digital beam forming is achieved with an

antenna array with a neat diagram. (7)

BTL 4

Analyzing

11. (i)Analyze the working principle of phased array antenna with neat

diagram. (7)

(ii)Describe the radiation mechanisms of binomial array with neat

sketches and derive the expression for array factor. (6)

BTL 4

Analyzing

12. Identify the direction of maximum and minimum radiation from the

resultant radiation of two identical radiators which are spaced d = 3 λ/4

meters apart and fed with currents of equal magnitude but with 180o

phase difference. (13)

BTL 4

Analyzing

13. Deduce an expression for the far field of a continuous array of point

sources of uniform amplitude and phase. Summarize and prove mathematically for finding directions of pattern nulls of the array. (13)

BTL 5 Evaluating

14. An antenna array consists of two identical isotropic radiators spaced

by a distance of d=λ/4 meters and fed with currents of equal

magnitude but with a phase difference β. Compose the resultant

radiation for β=00 and thereby identify the direction of maximum

radiation. (13)

BTL 6 Creating

PART-C

1 (i)Deduce the directivity of a given linear broadside , uniform array of

10 isotropic elements with a separation of λ/4 between the elements(7)

(ii) A linear broadside array consists of four equal isotropic inphase

point sources with λ/3 spacing . Construct the directivity and

beamwidth. (8)

BTL 5 Evaluating

2 A uniform linear array consists of 16 isotropic point sources with a

spacing of λ/4.If the phase difference is -90 o, Develop the directivity ,

HPBW , beam solid angle and effective apertures (15)

BTL 5 Evaluating

3 For an end fire consisting of several half wave length isotropic radiator

is to have a directive gain of 30 o. Evaluate the array length and width

of the major lobe. What will be these values for a broadside array (15)

BTL 6 Creating

4 A broadside array operating at 100 cm wavelength consists of four

halfway dipoles spaced 50 cm. Each element carries radio frequency

current in the same phase and magnitude of 0.5 amp. Interpret radiated

power , half width of major lobe. (15)

BTL 6 Creating

UNIT IV SPECIAL ANTENNAS

Principle of frequency independent antennas –Spiral antenna, Helical antenna, Log periodic.

Modern antennas - Reconfigurable antenna, Active antenna, Dielectric antennas, Electronic band

gap structure and applications, Antenna Measurements-Test Ranges, Measurement of Gain,

Radiation pattern, Polarization, VSWR.

PART A

Q.No Questions BT Competence

1. What is pitch angle of a helical antenna? BTL 1 Remembering

2. Define EBG structures. Write types of EBG structure. BTL 1 Remembering

3. State Rumsey’s principle. BTL 1 Remembering

4. How active antennas are wide interest for industrial applications? BTL 1 Remembering

5. Give applications of EBG structures in antenna engineering. BTL 1 Remembering

6. Recall about absolute gain and gain transfer. BTL 1 Remembering

7. Illustrate the difference between planar and conical spiral antenna. BTL 2 Understanding

8. Explain why frequency independent antennas are called so? BTL 2 Understanding

9. Compare and contrast wedges and pyramids. BTL 2 Understanding

10. Discuss the drawbacks in measurement of antenna parameters. BTL 2 Understanding

11. Classify reconfigurable antenna by considering the properties of a

base design.

BTL 3 Applying

12. Identify why antenna measurements are necessary? BTL 3 Applying

13. Show the instruments required to accomplish an antenna measurement task.

BTL 3 Applying

14. Point out the near and far field measurements. BTL 4 Analyzing

15. Conclude the applications of log periodic antenna. BTL 4 Analyzing

16. Select the requirements and types of anechoic chamber. BTL 4 Analyzing

17. Summarize the applications of helical antenna. BTL 5 Evaluating

18. Recommend the expressions for design ratio, spacing factor and frequency ratio of log periodic antenna?

BTL 5 Evaluating

19. On what principle slot antenna works? BTL 6 Creating

20. Generalize the antenna test range types. BTL 6 Creating

PART – B

1. What is the importance of helical antenna? Explain the

construction and operation of helical antenna with neat sketch. (13)

BTL 1 Remembering

2. (i) Write the classification of Electromagnetic Band-Gap (EBG)

structures and explain. (7)

(ii) Compare defected ground structure and EBG. (6)

BTL 1 Remembering

3. (i) Discuss in detail the measurement of Polarization. (7)

(ii) If a helical antenna has a spacing between turns 0.05m,

diameter 0.1m, number of turns equal to 20 and operates at 1,000

MHz, find the Null-to-Null beam width of the main beam and also

half-power beam width and directivity. (6)

BTL 1 Remembering

4. Explain the procedures for the measurement of VSWR. (13) BTL 1 Remembering

5. With neat schematic explain in detail about log periodic antennas.

What is the need for feeding from end with shorter dipoles and the

need for transposing the lines? Also discuss the effects of

decreasing alpha. (13)

BTL 2 Understanding

6. Summarize the initial, practical considerations, reconfiguration

mechanism of reconfigurable antenna. Interpret how dipole

antenna is reconfigurable by frequency. (13)

BTL 2 Understanding

7. Interpret the characteristics, feeding methods, and analytical

evaluation of dielectric resonator antenna. (13)

BTL 2 Understanding

8. Illustrate the antenna gain measurements by (i) gain comparison

method (ii) absolute method with neat diagram. (13)

BTL 3 Applying

9. (i) Identify the reciprocal relationship between Tx antenna and Rx

antenna. Explain about anechoic chamber. (7)

(ii) Demonstrate the compact antenna test ranges, near field and far

field with neat diagrams. (6)

BTL 3 Applying

10. Analyze in detail the normal mode and axial mode operation of the

helical antenna. (13)

BTL 4 Analyzing

11. (i) Design a log periodic antenna to obtain a gain of 9dB and to

operate over a frequency range of 125MHz to 500MHz, 𝝉=0.861

and σ=0.162. (7)

(ii) Examine the impact of reciprocity theorem in determination of

antenna impedance. (6)

BTL 4 Analyzing

12. Describe in detail the set up for measurement of Radiation pattern.

(13)

BTL 4 Analyzing

13. Explain the planar equiangular spiral, Archimedean spiral and

Conical spiral antenna with neat diagram and necessary design

equations. (13)

BTL 5 Evaluating

14. Discuss the principle of frequency independent behavior of LPDA

in detail and explain its construction. (13)

BTL 6 Creating

PART-C

1

Construct the experimental setup of measuring the unknown load

impedance using VSWR method and explain. (15)

BTL 5 Evaluating

2 For a 20 turn helical antenna operating at 3 GHz with

circumference C=10 cm and the spacing between the turns is 0.3 λ

. Evaluate the directivity and HPBW. (15)

BTL 5 Evaluating

3

A 16 turn helical antenna has a circumference of λ and turn

spacing of λ/4 . Predict the Half Power Beamwidth and axial ratio.

(15)

BTL 6 Creating

4 Summarize the concepts of

(i) Measurement of Polarization (8)

(ii) Group Velocity and Group Delay (7)

BTL 6 Creating

UNIT V PROPAGATION OF RADIOWAVE

Modes of propagation , Structure of atmosphere , Ground wave propagation , Tropospheric

propagation , Duct propagation, Troposcatter propagation , Flat earth and Curved earth concept

Sky wave propagation – Virtual height, critical frequency , Maximum usable frequency – Skip

distance, Fading , Multi hop propagation

PART A

Q.No Questions BT Competence

1. Define maximum usable frequency in a sky wave propagation. BTL 1 Remembering

2. Recall Critical frequency. BTL 1 Remembering

3. What is meant by multihop propagation? BTL 1 Remember

4. Show flat earth and curved earth propagation. BTL 1 Remembering

5. What can you say about Space diversity Reception? BTL 1 Remembering

6. Mention about the free space loss factor. BTL 1 Remembering

7. Discuss the effects of ground plane on low frequency

transmission.

BTL 2 Understanding

8. Is it possible to transmit horizontal polarized wave as a surface wave?

BTL2 Understanding

9. Give the factors that affect the propagation of radio waves. BTL2 Understanding

10. Summarize the features of Magneto-Ions Splitting. BTL2 Understanding

11. Sketch the layers of atmospheric structure. BTL3 Applying

12. Illustrate skip distance of sky wave. BTL 3 Applying

13. Find the range of LOS system when receive and transmit antenna heights are 10 m and 100m respectively.

BTL 3 Applying

14. Examine how fading is compensated in multipath propagation. BTL 4 Analyzing

15. Analyze the various types of diversity reception. BTL 4 Analyzing

16. Explore on Frequency Diversity reception. BTL 4 Analyzing

17. Express virtual height and actual height in terms of mathematical equations.

BTL 5 Evaluating

18. Find the critical frequency of an ionosphere layer which has an

electron density of 1.24x106cm-3

BTL 5 Evaluating

19. Outline the features of duct propagation. BTL 6 Creating

20. Formulate gyro frequency. BTL 6 Creating

PART-B

1. (i) Define the terms Skip distance and Virtual height. (7) (ii)Outline the wave propagation in complex environments.

(6)

BTL 1

Remembering

2. (i)What is the mechanism of space wave propagation over

ideal flat earth with a neat sketch? (7) (ii) How does the earth affect ground wave propagation? (6)

BTL 1

Remembering

3. (i) Write about sky wave propagation and explain the Effects of ionosphere abnormalities. (7)

(ii) Point out Critical frequency and maximum usable frequency in wave propagation. (6)

BTL 1 Remembering

4. (i) Review the effect of Earth’s magnetic field on ground wave propagation. (7)

(ii)Can you explain the mechanism of ionospheric propagation with neat diagram? (6)

BTL 1 Remembering

5. (i) List out the properties of radio waves. (7)

(ii) Outline the expression for field strength at the receiving antenna. (6)

BTL 2 Understanding

6. (i) Summarize the structure of the atmosphere and explain

each layer in detail. (9) (ii) Determine the critical angle of propagation for D-Layer, if

the transmitter and receiver are separated by 500km. (4)

BTL 2 Understanding

7. (i)Extend the attenuation characteristics for ground wave propagation. (6)

(ii) Explain the principle of troposcatter propagation (7)

BTL 2 Understanding

8.

(i) The receiver and the transmitter are located at the LOS on

the earth. For such a case, solve and find the distance between these two points on the earth. (8)

(ii) Illustrate the multihop propagation with diagram (5)

BTL 3 Applying

9. i) Construct a 2 ray model of sky wave propagation and

explain in detail. (6) ii) When the maximum electron density of the ionospheric

layer corresponds to refractive index of 0.92 at the frequency of 10 MHz, find the range if the frequency is MUF. The

height of the ray reflection point on the ionospheric layer is 400km. Assume flat earth and negligible effect of earth’s

magnetic field. (7)

BTL 3 Applying

10. (i)Examine whistlers and Faraday rotation. (7)

(ii) Discuss the effects of diffraction on EM Waves. Explain about the models of diffraction. (6)

BTL 4 Analyzing

11. (i) Analyze about Duct propagation and explain in detail. (7) (ii) Research surface wave propagation (6)

BTL 4

Analyzing

12. (i) A free space LOS microwave link operating at 10GHz

consists of a transmit and a receive antenna each having a gain of 25dB. The distance between the two antennas is 30km and

the power radiated by the transmit antenna is 10W. Calculate the path loss of the link and the received power. (6)

(ii) Derive the expression for the MUF for flat earth and

curved earth. (7)

BTL 4 Analyzing

13. (i) Explain the how the EM waves are propagated in troposphere layer. (7)

(ii) Consider the effect of EM waves in curved earth and flat earth configuration. (6)

BTL 5 Evaluating

14. Draw the electron density profile chart of an ionosphere and explain. Also derive an expression for the effective relative

dielectric constant of the ionosphere. Explain about reflection and refraction of waves in ionosphere. (13)

BTL 6 Creating

PART-C

1

A mobile link has to be established between two points spaced

away 1500 km via ionosphere layer of density 4.5X106 cm-3 at a

height of 150 km. Calculate the maximum frequency which can be

communicated, critical frequency and skip distance. (15)

BTL 5 Evaluating

2 Evaluate the field strength of a space wave neglecting the

curvature of the earth. (15)

BTL 5 Evaluating

3

Assume the reflection takes place at a height of 400 Km and

maximum density corresponds to 0.9 refractive index at 10 MHz

What will be the range for which MUF is 10 MHz? Consider

(i) Earth is flat

(ii) Earth is curved (15)

BTL 6 Creating

4 (i) What is the radio horizon of a television antenna placed at a

height of 166 meters? If the signal is to be received at a distance of

66Km, what should be the height of receiving antenna? (10)

(ii) A pulse of a given frequency transmitted vertically upward is

received back after a period of 2 msec. Find the virtual height of

the reflected layer. (5)

BTL 6 Creating

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