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    21ET62

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    Ete previous year question paper of dsp subject ,rvce

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    21ET62

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    hellouniversx1
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    Ete previous year question paper of dsp subject ,rvce

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    Ete previous year question paper of dsp subject ,rvce

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
    Download as pdf or txt
    5 views3 pages

    21ET62

    Uploaded by

    hellouniversx1
    Ete previous year question paper of dsp subject ,rvce

    Copyright:

    © All Rights Reserved
    Download as PDF, TXT or read online from Scribd
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    21ET62

    USN
    RV COLLEGE OF ENGINEERING®
    (An Autonomous Institution Affiliated to VTU)
    VI Semester B. E. Examinations Sept/Oct – 2024
    Electronics and Telecommunication Engineering
    ANTENNA THEORY AND DESIGN
    Time: 03 Hours Maximum Marks: 100
    Instructions to candidates:
    1. Answer all questions from Part A. Part A questions should be answered in first
    three pages of the answer book only.
    2. Answer FIVE full questions from Part B. In Part B question number 2 is
    compulsory. Answer any one full question from 3 and 4, 5 and 6, 7 and 8, 9 and
    10.

    PART-A M BT CO

    1 1.1 The antenna used for digital applications is -------- 01 1 1


    1.2 List any two causes for the wave propagation within Troposphere. 01 1 1
    1.3 A helical antenna is used for satellite tracking because of its-------- 01 1 1
    1.4 A HPBW of a monofilar axial-mode helical antenna can be
    obtained with the relation -------- 01 2 3
    1.5 An antenna has 12Ω Loss resistance, radiation resistance is 72 Ω
    and gain is 20. Calculate the efficiency of the antenna if the
    directivity is 10. 01 3 1
    1.6 Evaluate the roughness factors for the earth at 10 MHz if σ =5 for
    θ =300 01 3 1
    1.7 Calculate the HPBW and BWFN for the antenna radiation pattern
    𝐸 = 𝑐𝑜𝑠 2 𝜃 for 00 ≤ 𝜃 ≤ 900 . 02 3 3
    1.8 A half wave dipole radiating in free space is driven by a current of
    0.5 amp at the terminals. Calculate Electric field and Magnetic
    field intensity at one Km from antenna at angles of 450 . 02 3 2
    1.9 Calculate the maximum effective aperture of an antenna which is
    operating at a wavelength of 2 meters and has a directivity of 100. 02 3 2
    1.10 Find the basic path loss for a communication from the moon to
    earth operating at 3000 MHz. Assume the distance between moon
    and earth is 384000 Km 02 3 1
    1.11 Define the following terms:
    i) Critical Frequency
    ii) Skip Distance 02 1 1
    1.12 Obtain the dimensions of Three element Yagi-uda antenna at 100
    MHz 02 2 3
    1.13 For a circularly polarized 16-turn antenna of an end fire radiation
    𝜆
    pattern having a circumference of λ and turn spacing of . Find
    4
    i) HPBW
    ii) Axial Ratio 02 3 2

    PART-B

    2 a Derive an expression for the radiation resistance of short dipole


    antenna 06 4 1
    b Derive the Hansen and woodyard condition of array of point
    sources. Also derive the conditions for Half power beamwidth and
    First Null beamwidth. 05 4 2
    c An array of 4 Isotropic antennas placed along a straight line.
    Distance between the adjacent elements is 𝜆/2. The peak is to be
    obtained in a direction 60° from the axis of the array. What should
    be the phase difference between the adjacent elements? Complete
    the Radiation pattern and find BWFN and HPBW 05 3 2

    3 a Describe the construction and basic principles of operation of a


    helical antenna with
    i) Modes of operation
    ii) Ground plane configurations 06 2 3
    b A small parabolic reflector (dish) of revolution, referred to as a
    paraboloid, is now being advertised as a TV antenna for direct
    broadcast. Assuming the diameter of the reflector is 1 Meter,
    determine at 3GHz the directivity (in DB) of the antenna if the feed
    is such that
    i) The illumination over the aperture is uniform (ideal).
    ii) The taper efficiency is 80% while the spill over the efficiency
    is 85%. Assume no other losses. What is the total aperture
    efficiency of the antenna (in dB) ? 05 3 3
    c Explain construction of Parabolic reflector and explain its feeding
    mechanisms. 05 2 3

    OR

    4 a Illustrate the Microstrip Patch Antenna design using


    Transmission Line model and its working 08 3 3
    b Calculate the following parameters for a Pyramidal horn antenna
    whose Aperture dimensions are 9 x 8 cm at 5GHz
    i) Directivity
    ii) Gain as Power ratio. 04 3 3
    c Explain the working of a Ground Plane Antenna with neat
    diagram 04 2 1

    5 a Categorize various Mobile station antennas with their


    construction and necessary equations. 05 2 1
    b Discuss the different modes of wave propagation 05 1 1
    c Explain the structure of Ionosphere with the characteristics of
    each layers 06 2 1

    OR

    6 a Derive the expression for Friss Transmission formula and how it


    is related to Tropospheric Propagation 06 4 1
    b Discuss the design aspects of an Embedded antennas 04 2 1
    c Assume that the reflection takes place at 350 km and that the
    maximum density in the Ionosphere corresponds to a 0.8
    refractive index at 15 Mhz. What will be the rage (Assume flat
    earth) for which the MUF is 20 MHz. 06 3 1

    7 a Discuss the various Wireless Communication antennas present in


    a Smartphone. 06 1 4
    b Explain the various feeding techniques used for Microstrip array
    antenna. 06 2 2
    c Differentiate between Linear and Planar Microstrip Arrays with
    neat diagram. 04 1 2

    OR
    8 a Explain the working of Active Phased array antenna system with a
    neat block diagram 06 2 2
    b Illustrate the Antenna Switching Techniques with an example. 06 3 4
    c Compare the different Smart antenna configurations 04 1 4

    9 a Explain the working of Vector network analyzer with neat block


    diagram. 08 2 4
    b Discuss how polarization and Antenna efficiency measurement
    with patterns for test antenna are performed? 08 2 4

    OR

    10 a Illustrate with neat diagram how impedance measurement of an


    antenna can be performed. 08 3 4
    b Explain the Gain measurement by Absolute and Comparison
    method of Gain measurement 08 2 4

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