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Name of the College : P.E.S College of Engineering
University : Visvesvaraya Technological University
Department : Electronics and Communication Engineering
Subject Code/Name : P08EC63/Microwave devices and Integrated Circuits
Degree : B.E
Sem : VI
Website : pescemandya.org
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/pescemandya.org/4683-ec_question%20paper.pdf

Microwave devices & Integrated Circuits

Sixth Semester B.E Degree Examination :
Duration : 3 hrs
Max. Marks :100

Related : P.E.S College of Engineering P08EC62 Computer Communication Networks B.E Model Question Paper : www.pdfquestion.in/4681.html

Note : Answer any FIVE full questions selecting at least Two questions from each part.
PART-A :
1.a) Derive the equation for the following at microwave frequency.
i) Propagation constant ii) Attenuation constant iii) Phase constant iv) Characteristic impedance & v) Phase velocity 12

b) Derive the relationship between SWR and reflection co-efficient. 03
c) The characteristic impedance of the line is 50 O and SWR ?=2 when the line is loaded. When the line is shorted, the minima shifts 0.15? towards load. Determine the load impedance. Use Smith chart. 05

2.a) Give the comparison between wave guide and co-axial cable. 06
b) An air filled rectangular wave guide of inside dimension a =7 cms and b= 3.5 cm operates in the dominant TE 10 mode.

i) Find the cut-off frequency
ii) Determine phase velocity of the wave in the guide at a frequency of 3.5 GHz.
iii) Determine the guide wavelength at the same frequency. 06

c) How to realize the four –port circulator with directional couplers and phase shifter? Explain. 08

3.a) Explain mechanism of oscillation in Reflex klystron oscillator with neat sketches? 10
b) Explain TWT amplifier with neat sketches? 10
4.a) Explain the relation between incident and reflected waves in terms of scattering parameters for a two port network. Also explain physical significance of sparameters. 08

b) Which properties are common in S,Z and Y matrices? 03
c) Two transmission lines of characteristic impedances Z1 and Z2 are joined at plane PP’
Express s- parameters in terms of impedances. 09

PART-B :
5.a) Explain with a neat sketch a precision rotary phase shifter. 06
b) A 20 mw signal is fed into one of collinear port 1 of a lossless H- plane T-junction calculate the power delivered through each when other ports are terminated in matched load. 06
c) With a neat sketch explain the different types of strip lines. 08

6.a) Explain with relevant figures the fundamental concept of RWH theory. 05
b) A typical h-type GaAS Gunndiode has the following parameters:
Threshold field= Eth = 2800 v/cm
E=3200 V/cm
Device length = L= 10µm
Doping concentration =no =2×1014 cm-3
Operating frequency =f=10GHz.
i) Compute electron drift velocity
ii) Calculate the current density
iii) Estimate the negative electron mobility. 04

c) Explain the principle of operation of read diode with suitable diagrams. 06
d) Draw the equivalent circuit for parametric amplifier and explain. 05
7.a) Briefly explain the characteristics of micro strip line. 06

b) A lossless parallel strip line has a conducting strip width W. The substrate dielectric separating the two conducting strips has a relative dielectric constant ?rd of 6 and a thickness d of 4 mm. Evaluate w, c and up ( in usual notations). 08

c) Obtain attenuation losses in parallel strip lines for both conductor and dielectric. 06
8.a) Distinguish between thick film and thin film technology. Describe the fabrication process of MMIC and hybrid MIC’s. 10
b) Describe the basic fabrication process of MOSFET’s? 10

Antennas and Wave Propagation Model Question Paper :
PART-A :
1. a) Define the following antenna terminologies.
i) Antenna field zones
ii) Effective height
iii) Effective Aperture 08

b) Determine the directivity of the following source.
i) u = um cos3
ii) u = um sin sin2 06
c) Determine the effective aperture and directivity of a linear ?/2 dipole Antenna. 06

2. a) Derive an expression for the resultant field of an array of N isotropic source and obtain the condition for operating it as
i) Broad side array
ii) End fire array 08

b) Explain the concept of principle of pattern multiplication with an example. 06
c) Obtain the field equation for a linear uniform array of 6 isotropic point sources spaced ?/2 distances apart. The power is applied with equal amplitude and in phase. Also find FNBW. 06