EC6602-Antenna and Wave Propagation Semester/EC6602-Antenna … · valliammai engineering college...
Transcript of EC6602-Antenna and Wave Propagation Semester/EC6602-Antenna … · valliammai engineering college...
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