Name of the College : Mahatma Gandhi University
Department : Communication Engineering
Subject Code/Name : MECCE 104/Communication Networks
Sem : I
Website : mgu.ac.in
Document Type : Model Question Paper
Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/mgu.ac.in/5060-MECCE%20105-2%20Antenna%20Theory%20and%20Design.pdf
Antenna Theory & Design Question Paper :
M.TECH Degree Examination :
Model Question Paper
Specialization: Communication Engineering
Related : MGU MECCE104 Communication Networks M.Tech Model Question Paper : www.pdfquestion.in/5059.html
First Semester :
MECCE 105-2 Antenna Theory And Design
(Regular-2013 Admissions)
Time: Three Hours
Maximum: 100 marks
Each question carries 25 marks. :
Module I :
1. a) Explain how a ?/2 dipole is acting as an ideal radiator which is energized by an alternating supply. Why a dc cannot be radiated? (10)
b) State Reciprocity theorem. Show how it is used in antenna measurement. (10)
c) State the Duality Power Theorem and explain. (5)
OR
2. a) What is the significance of radiation pattern? (5)
b) Draw the radiation pattern of a horn antenna. (2)
c) Explain the shape of the above said pattern and also explain how it is formed with the help of required diagram and equation. (10)
d) Give the radiation equation and explain (8)
3. a) What is continuous line-source distribution? How the radiation characteristics of continuous line-sources are analyzed? (5)
b) Explain the Schelkunoff method of synthesis of antenna array. (10)
c) Design a linear array of isotropic elements placed along the z-axis such that the zeros of the array factor occurs at ?=00, 600, 1200. Assume that the elements are spaced ?/4 apart and that the progressive phase shift between them is00.
Find the required number of elements. (2)
Determine their excitation coefficients (3)
Write the array factor. (3)
OR
4. a) Explain the Taylor design procedure for continuous distribution with required mathematical support. (10)
b) Explain the space factor of Circular aperture. (5)
c) Explain the Woodward – Lawson synthesis for discrete linear array. (10)
5. a) Explain the basic characteristics of Micro strip patch. (5)
b) What is transmission line model of rectangular patch and explain the fringing effect, effective length and fringe factor. (10)
c) Design a rectangular patch antenna using a substrate with dielectric constant=2.2 and height=0.1588 cm, so as to resonate at 10GHz. (10)
OR
6. a) Extract the mathematical expression for modes in a rectangular patch. (10)
b) Find the fields radiated from micro strip for the principal E-plane and H-plane. (7)
c) A micro strip transmission line of beryllium oxide of dielectric const 6.8 has a width-to-height ratio of 1.5. Assuming that the thickness-to-height ratio is 0, determine Effective dielectric constant , (4)
Characteristic impedance of the line. (4)
7. a) Explain the terms cell splitting and sectorized systems. (5)
b) Explain how the DOA algorithm determines the directions of incoming signals. (10)
c) Design the DOA of a two-element array. Show that the angle of arrival/incidence can be determined on the basis of time delays and geometry of the system. (10)
OR
8. a) Explain the Least Mean Square algorithm in adopting weights. (10)
b) What is Rayleigh Fading? (5)
c) What is MANET? Explain the MAC protocol of IEEE 802.11. (10)
Syllabus :
Module I :
Basic concepts in Antenna theory : Radiation process- mechanism of radiation of EM energy from a dipole and horn (concept only) radiation pattern. Antenna parameters (concept and expressions) – radiation equation, pattern, beam width, aperture, effective height, antenna field region/zone.
Reciprocity theorem (details).self-impedance and mutual impedance (concepts). Effect of ground plane –image theory, Small loop antenna, Duality theorem and applications.
Communication link – receiving and transmitting antenna, electrical equivalent ckt., Point source concept.
Module II :
Antenna Synthesis : Continuous source – line-source, discretization of continuous sources, Schelkunoff Polynomial method, Fourier Transform method, Woodward-Lawson method, Taylor line-source-design procedure.
Taylor line source (one-parameter),Triangular, cosine and cosine-squared amplitude distributions, Line-source phase distributions, Continuous aperture sources-Rectangular aperture, circular aperture.
Module III :
Microstrip antennas : Basic characteristics, feeding methods, methods of analysis. Rectangular patch- Transmission line model, Cavity model, Directivity –single slot and two slots, Circular patch, Quality factor, bandwidth and efficiency, Input impedance, Coupling.