Download AKTU (Dr. A.P.J. Abdul Kalam Technical University (AKTU), formerly Uttar Pradesh Technical University (UPTU) B-Tech 5th Semester (Fifth Semester) 2015-2016 Antenna Wave Propagation Eec 504 Question Paper
(Following Paper ID and Roll No. to be filled in your
Answer Book)
Roll No.
B.Tech.
(SEM. V) THEORY EXAMINATION, 2015-16
ANTENNA & WAVE PROPAGATION
[Time : 3hours] [Maximum Marks : 100]
Section-A
l. Attempt all sections. All sections carry equal marks.
Write ansWer of each section in short. (10X2=20)
(a) Write three methods which might be used to
generate circular polarisation for a lowearth-orbit
satellite antenna communication system.
(b) Explain why all practical antenna necessarily have
maximum directivity greater than unity.
(c) What are the dif?culties in waveguide Propagation?
(d) F ind the terminal impedance of in?nitesimally thin
,1/2 slot antenna when the impedance of
in?nitesimally ,1/2 dipole antenna is 73+
42.5jQ.
(1) P.T.O.
(e) What is radiation resistance? 4. Explain in detail about folded dipole antenna. How
(0 What do yoh mean by resonant and Non-resonant impedance of folded dipole antenna is related to the
long wire abtenna? . number ofdipoles and radius of dipoles?
D f t dP t .
(g) e me an enna array an on source 5. Explain the principle of pattern multiplication and its
(b) What are the advantages and disadvantages of advantages. Give one example of Pattern Synthesis.
rhombic antenna? ?
(i) What is anechoic chamber? Forwhat purpose if is . 6. ' Write a short note on Microstrip antenna and Slot
used? antenna.
(i) What do you understand by line of sight?
7. What are themethods for Gain Measurement?
Section-B
? 8. Describe the applications of Loop antenna? Write down
Note: Attempt any ?ve questions from this section. ?V the comparison between parabolic and re?ector
?06:50) ~ antennas?
I
2. Derive the FriIS transmission line formula. Calculate the I 9 Write short note on Ground wave propagations and space
effective aperture of dipole length 2cm at a frequency
. wave propagation?
of 1.2 GHz. What will be the power received for an ?
incidental power density of 2m W/m?? Section-C
Note: Attempt any two questions from this section
3. Esplam the concept of Antenna Temperature. Calculate (1 5 x 2:30)
the maximum effective aperture of a beam antenna having
a HPBW of 30 degree and 35 degree in perpendicular
planes intersecting in beam axis. Assume negligible side
lobes.
10. Explain the various modes of operation of a helical
antenna. What is Horn antenna? Explain its applications.
w? ?4 ?-???-v-.~??..?.___. - ?...V.a__-..-
(2) EEC-504 (3) P.T.O
' 11.
12.
Explain the mechanism of Ionospheric propagation with
neat diagram. Inran IonOSpheric propagation, re?ection
take place at a height of 400 km and that the maximum
denesity in the ionosphere corresponds to a 0.9 refractive
index at lOMl-Iz. Determine the ground range for which
this frequency is MUF take earth?s curvature into
consideration;
(a) ' Discuss the method for the measurement of
Radiation Pattern
(b) Design a three-element Yagi-Uda antenna at an
operating frequency of 250MHz. ?
(c) For end ?re array consisting of several halfwave
length long isotropic radiators to have a directive
gain of 30. Find the array length and FNBW. What
will be these values for Broadside array?
(4) EEC-504/3200
This post was last modified on 29 January 2020