Download GTU B.Tech 2020 Summer 6th Sem 2161003 Antenna And Wave Propagation Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 6th Sem 2161003 Antenna And Wave Propagation Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER? VI EXAMINATION ? SUMMER 2020
Subject Code: 2161003 Date:27/10/2020
Subject Name: ANTENNA & WAVE PROPAGATION
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.


Q.1 (a) Explain the polarization of waves and describe elliptical polarization.
03

(b) Discuss the antenna field zone.
04

(c) Define Antenna and enlist its functions. Compare it with transmission
07
line.



Q.2 (a) Determine the distance from short dipole operating at 1MHz at
03
which radiation filed is 4 times the induction field.

(b) How does the Friis transmission theory help to determine loss between
04
the two antennas located in free space? Explain with necessary formula
and theory.

(c) Define the following terms.(draw necessary figures and write equations
07
if any)
i)
Front-to-back ratio
ii)
Resolution
iii)
Antenna apertures-physical and effective apertures
iv)
Beam efficiency, stray factor
v)
Radiation resistance


OR


(c) Starting from retarded current, derive an expressions for electric and
07
magnetic components of a short dipole antenna if the spherical system
is defined in r, and .
Q.3 (a) Estimate directivity of an antenna with HP=2 and HP=1.Find gain of
03
this antenna if efficiency factor k=0.5.

(b) Explain the experimental setup for the measurement of Gain of antenna.
04

(c) Enlist various types of horn antennas. Describe their functioning.
07
Explain corrugated horn antenna.


OR

Q.3 (a) Explain the principle of Folded dipole antenna with clean and neat
03
figure.

(b) Explain how log-periodic antenna is works as broadband antenna.
04

(c) Define Pattern Multiplication principle. Using it, explain radiation
07
pattern of 4 isotropic elements fed in phase, spaced /2.



Q.4 (a) Explain reflector- lens antenna.
03

(b) Explain practical design consideration for the helical antenna.
04

(c) Describe the working principle, design and applications of microstrip patch
07
antenna. Explain the physical significance of fringing field.

OR

Q.4 (a) Explain Cassegrain feed with necessary figure.
03

(b) Compare the far field equations of small loop with short dipole.
04
1

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(c) What do you mean by non-resonance antenna? Explain the design of
07
rhombic antenna and enlist its advantages and disadvantages.



Q.5 (a) Explain multihop propagation briefly.
03

(b) Explain babinet's principal.
04

(c) Explain the Different modes of Radio wave propagation.
07


OR
Q.5 (a) Explain the features of Yagi Uda antenna
03
(b) Define the following terms.(draw necessary figures)
04
(i) Maximum usable frequency (ii) Skip distance
(c) Explain the different layers of atmosphere.
07

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