DR.
BABASAHEB AMBEDKAR TECHNOLOGICAL UNIVERSITY, LONERE
Supplementary Summer Examination – 2024
Course: B. Tech. Branch : Electronics Engineering Semester : VII
Subject Code & Name: BTEXC701_Y22 Antennas and Wave Propagation
Max Marks: 60 Date: 01/07/2024 Duration: 3 Hr.
Instructions to the Students:
1. All the questions are compulsory.
2. The level of question/expected answer as per OBE or the Course Outcome (CO) on
which the question is based is mentioned in ( ) in front of the question.
3. Use of non-programmable scientific calculators is allowed.
4. Assume suitable data wherever necessary and mention it clearly.
(Level/CO) Marks
Q. 1 Solve Any Two of the following. 12
A) Derive the wave equation for the electric field in a homogeneous, isotropic, CO01 6
and source-free medium starting from Maxwell's equations in phasor form.
B) Describe the reflection of a plane wave at normal incidence on the interface CO01 6
between two media with different refractive indices. Also determining the
Reflection and Transmission Coefficients
C) In a medium, a uniform plane wave is described by the electric field CO01 6
E = 4e-αz sin (108t – βz) ay V/m.
Given the medium's characteristics: εr = 2, µr = 15 and σ = 3 S/m, determine
the values of α, β and H.
Q.2 Solve Any Two of the following. 12
A) Explain structure of atmosphere in detail. CO03 6
B) Write a short note on Ionospheric abnormalities. CO03 6
C) A communication link is to be established between two stations using λ/2 CO02 6
antenna of maximum gain. The transmitter power is 2kW. The transmitter and
receiver are separated by the distance of 150 km. If the operating frequency
is 200 MHz, Find maximum power received by receiver (GR = GT = 1.64).
Q. 3 Solve Any Two of the following. 12
A) Explain radiation mechanism for dipole with the help of neat diagram. CO02 6
B) Explain the different types of antennas commonly used in communication CO02 6
systems along with their respective applications.
C) Define radiation power density. Determine the total radiated power if the CO02 6
radial component of radiated power density of an antenna is given by
𝑠𝑖𝑛𝜃
Wrad = arA0 (W/m2)
𝑟2
Where A0 is peak value of the power density, θ is usual spherical coordinate,
and ar is the radial unit vector.
Q.4 Solve Any Two of the following. 12
A) Derive an expression for the fields radiated by infinitesimal dipole. CO03 6
B) Define: (a) MUF, (b) virtual height, (c) directivity, (d) gain, (e) antenna CO01 6
efficiency and (f) radiation pattern.
C) Find the radiation efficiency of a single turn and a ten turn small circular loop CO03 6
radiating in a free space at frequency of 50 MHz. The radius of the loop is
λ/10, the radius of wire is 10-4λ, and the turns are spaced 410-4λ apart and
the conductivity of the wire is 5.7 107 (S/m).
Q. 5 Solve Any Two of the following. 12
A) Explain Rhombic antenna in detail along with its advantages, disadvantages CO03 6
and applications.
B) Write a short note on traveling wave antennas. CO03 6
C) Explain different feeding techniques used in Microstrip antenna. CO03 6
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