P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 1/22 SL. NO. SUBJECTS CODE STAFF PAGE NO 1. ANTENNA THEORY AND DESIGN 10EC011 Ms.Kavitha Y.C. 2-5 2. ADVANCED DIGITAL COMMUNICATIONS 10EC006 Mr.Raghavendra M.J. 6-7 3. PROBABILITY AND RANDOM PROCESS 10EC124 Ms. Rekha S.S. 8 4. DIGITAL CIRCUITS AND LOGIC DESIGN 10EC029 Ms. Ravikant G Biradar 9-19 5. CMOS VLSI DESIGN 10EC021 Mr.Prabhakar Mishra 20-22 Class Incharge : Ms. Kavitha Y.C. M.Tech 1st SEM QUESTION BANK INDEX
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P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 1/22
SL. NO.
SUBJECTS CODE STAFF PAGE NO
1. ANTENNA THEORY AND DESIGN
10EC011 Ms.Kavitha Y.C.
2-5
2. ADVANCED DIGITAL COMMUNICATIONS
10EC006 Mr.Raghavendra M.J.
6-7
3. PROBABILITY AND RANDOM PROCESS
10EC124 Ms. Rekha S.S.
8
4. DIGITAL CIRCUITS AND LOGIC DESIGN
10EC029 Ms. Ravikant G Biradar
9-19
5. CMOS VLSI DESIGN 10EC021 Mr.Prabhakar Mishra
20-22
Class Incharge : Ms. Kavitha Y.C.
M.Tech 1st SEM QUESTION BANK
INDEX
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 2/22
QUESTION BANK
ANTENNA FUNDAMENTALS AND DEFINITIONS
Subject code: 10EC011 Faculty: Y.C.K 1. A) Explain the radiation mechanism for an antenna. 10 marks
B) Explain the terms with respect to antenna: i)Directivity ii)gain iii) antenna impedance iv)radiation
efficiency v) polarization. 10 marks
2. A) Explain the procedure for finding the solution of Maxwell‟s equation for radiation problems B) Give the procedure to find solution of Maxwell‟s equation for radiation problems for an ideal dipole.
A) Explain Farfield conditions and field regions
B) Give the steps for evaluation of radiation fields 20 marks
3. A) With a neat diagram explain radiation pattern and define its parameters. 12 marks B) An Antenna radiates a total power of 100 watts in the direction of maximum radiation, field strength at
a distance of 10km was found to be 12mv/m, what is the gain of an antenna, assume free space
Propagation. If the efficiency is 90%, find the directivity 8 marks
4. A) An antenna has a far-field pattern which is independent of Φ but varies with as follows:
F=1 for o0 ≤ ≤ 300
F=0.5 for 600≤ ≤ 1200
F= 0.707 for 1500 ≤ 1800
F=0 for 300 ≤ ≤ 600 and 1200 < <1500
Find directivity. Also find directivity in the direction =900. 7 marks
B) Compute the gain of an antenna which has a radiation efficiency of 95% and the following radiation
pattern F() = 1 00≤ < 200
.707 200≤ <1200
0 1200≤ <1800 5 marks
C) A power pattern is given by cos for 0<= <=/2 and is zero for /2<=<= 8 marks
i) calculate the directivity for n=1,2,and 3 ii) explain the directivity value for the case of n=0.
5. A) Two space crafts are separated by a distance of 100mm, each has an antenna with D=1000 operating at 2.5 GHz. If craft A's receiver requires 20 db over 1pw,what transmitter power is required on craft B to achieve this signal level 10 marks B) What is the maximum power received at a distance of 0.5km over a free space 1GHz circuit
consisting of a transmitting antenna with a 25db gain and a receiving antenna with 20 db gain, the gain
is w.r.t isotropic source, the transmitting antenna input is 150 watts 10 marks
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 3/22
6. A) Calculate the Directivity for the following unidirectional sources having the following power patterns
U= Um sin sin2 Φ
U= Um sin sin3 Φ
U= Um sin2 sin3Φ
U has a value only for 0<< and 0<Φ and 0 else where. 7 marks
B) Calculate the Directivity of the unidirectional cosine power pattern U= Um cos 7 marks
C) An Isotropic radiator has a field strength given by E=10I/r volts/m, where I is the terminal current
and „r‟ is the distance in meters. Find the radiation resistance. 6 marks
Resonant antennas:
8. A) Design an optimum directivity vee dipole to have directivity of 6dB 10 marks
B) Calucalte input impedance of a folded dipole of length L=.4 wire size2a=.001 and
Wire spacing d=12.5a using the transmission line model. 10 marks
9. Explain yagi-uda antennas 20 marks 10. Explain microstrip antennas 20 marks 11. A) Derive the expression for the electric field of a short dipole 10 marks
B) Derive the expression for the radiation resistance of a short electric dipole 10 marks
Antenna arrays:
12. Derive an equation for the total field produced at a large distance in the direction of Φ due to two isotropic point sources having
a) Same amplitude and phase
b) Same amplitude and opposite phase
c) same amplitude and phase quadrature
d) same amplitude and any phase
e) unequal amplitude and any phase 20 marks
13. For the a) to c) find the maximum, minimum and half Power Points and plot the field pattern 8 marks
14. 'N' identical antennas are uniformly spaced along a straight line and energized by currents of equal amplitude but differing by phase successively. Derive an expression for field intensity at a distant point in the direction of Φ 10 marks
15. Show that the magnitude of the array factor of a linear array of 'n' isotropic point sources of equal amplitude and spacing is given by E=(sin nψ /2) /(n sin ψ /2) 8 marks
16. What is a broadside array obtain an expression for the direction of Pattern Maxima, minima and the width of the Principle lobes (Beam width) 5 marks
17. What is a end fire array obtain an expression for the direction of Pattern Maxima, minima and the width of the Principle lobes (Beam width) 5 marks
18. Distinguish between broadside array and end fire array. What specific properties make them useful at H.F 10 marks
19. Explain the principle of pattern multiplication with an example 10marks
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 4/22
20. What is an extended end fire system obtain an expression for pattern maxima and beam width compare with this an ordinary end fire system. 8 marks
21. a) δ=0 and Eo= sin Φ for each array
b) δ=0 and Eo= cos Φ for each array
c) δ=Π and Eo= cos Φ for each array
d) δ=Π and Eo= sins Φ for each array
e) δ=Π/2 and Eo= cos Φ for each array 16 marks
Where δ is the phase difference between the sources
22. Two space crafts are separated by a distance of 100mm, each has an antenna with D=1000 operating at 2.5 GHz. If craft A's receiver requires 20 db over 1pw,what transmitter power is required on craft B to achieve this signal level 8 marks
23. What is the maximum power received at a distance of 0.5km over a free space 1GHz circuit consisting of a transmitting antenna with a 25db gain and a receiving antenna with 20 db gain, the gain is w.r.t isotropic source, the transmitting antenna input is 150 watts. 8 marks
24. What is the maximum Effective aperture of a microwave antenna with a directivity of 900? 8 marks 25. A 200 kw medium wave transmitter employs an antenna with a directivity of 1.5 in the horizontal
plane, determine the electric field strength at a distance of 1.5 km. 6 marks 26. A Linear array consists of 4 isotropic point sources, the distance between the adjacent element is λ/2,
the power applied with equal magnitude and a phase difference of -dr. Obtain the field pattern and find BWFN and HPBW 10 marks
27. What are the advantages of using a folded dipole over a half wave dipole? 28. Explain the term linear array and bring out the properties of broad- side and end- fire arrays. Sketch
the directional pattern for these arrays. 6 marks 29. Using the principle of pattern multiplication show that a linear array with binomial amplitude
distribution has a pattern for these arrays. 6 marks 30. Show that the HPBW of a long uniform broad side array is given by 50.8 degrees /L/ λ
6 marks
Broad band antennas
31. Explain helical geometry. 20 marks 32. Explain Normal & Axial mode radiation of a helical antenna 20 marks 33. Derive the expression for axial ratio for a helix radiating in the axial mode 20 marks 34. Explain radiation pattern for traveling wave antenna 20 marks 35. With neat diagram explain radiation pattern for i) finite biconical antennas ii)infinite biconical antenna
iii)discone antenna 20 marks 36. Explain i)sleeve monopoles ii) sleeve dipole 20 marks 37. Write a note on spiral antennas 20 marks 38. Explain log- periodic antenna 20 marks
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 5/22
Aperture antennas
39. Explain why and how a paraboloidal reflector may be used as directive antenna. 20 marks 40. Write a short note on parabolic reflector 20 marks 41. Give the construction of a parabolic reflector, what it tends to be a highly directional antenna
20 marks
42. Give gain and efficiency expression for reflector antennas 20 marks 43. Explain different reflector antennas 20 marks 44. Explain feed antennas used in practice 20 marks 45. Explain general feed model 20 marks 46. Derive expression for directivity using aperture field integration method 20 marks 47. Give design principles used in feed antennas 20 marks
Antenna synthesis:
48. Explain i) woodward –lawson sampling synthesis procedure and ii) fourier transform method for line source shaped beam 20 marks
49. For linear array shaped beam explain : i) fourier series synthesis method ii) wood ward-lawson sampling method. 20 marks
50. Explain i) dolph-chebyshev linear array method and ii) Taylor line source methods for low side lobe narrow main beam. 20 marks
51. Synthesize a sector pattern with c=0.5 using the fourier series method for an array of 20 elements that are spaced 0.6λ apart i) determine the element locations and current values ii) plot the radiation pattern in linear, rectangular form as a function of w 20 marks
52. Design a dolph-chebyshev broadside array of five,half wave lengthed spaced elements for 30db side lobes i)verify the current distribution ii) compute the directivity 20 marks
53. Design a broad side dolph-chebyshev array with six, 0.6 λ spaced elements for -25db side lobes i) obtain the element currents ii) plot the pattern in logarithmic rectangular form 20marks
Method of moments , CEM for antennas:
54. Explain pocklington‟s integral equations 20 marks 55. Explain weighted residual method for method of moments. 20 marks 56. Derive moment of method procedure. 20 marks 57. Explain wedge diffraction theory to determine the field in the forward scattering direction 20 marks
58. Explain ray fixed coordinate system 20 marks 59. Explain e-plane analysis of horn antennas 20 marks 60. Illustrate the :i)radiation by a slot on a finite ground plane ii) radiation by a monopole on a finite
ground plane 20 marks 61. Explain the UTD method for cylindrical parabolic antenna 20 marks 62. Explain the concept of equivalent currents 20 marks 63. Explain the diffraction concept for curved surfaces 20 marks 64. Explain method of stationary phase 20 marks 65. Explain physical theory of diffraction 20 marks
**********
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 6/22
QUESTION BANK
ADVANCED DIGITAL COMMUNICATION
Sub.code:10EC006 Faculty: MJR
1) Obtain an expression for the maximum SNR of a Matched filter demodulator using Time domain
approach.
2) State and prove different properties of Matched filter
3) Explain M-ary PSK modulation scheme with its basis functions and obtain an expression for the
union bounded probability of error.
4) Describe a typical square M-QAM modulation scheme(say 16-QAM).Obtain an expression for the
probability of error for a square M-QAM .
5) State the time domain expressions for a DPSK modulated signal. With the help of a block diagram
explain how a DPSK signal is demodulated and state the probability of error. How does this Pe
compare with coherent BPSK.
6) Explain Maximum – Likelihood Sequence Detection algorithm
7) Obtain an expression for the probability of error for Binary Modulation.
8) Obtain an expression for the probability of error for M-ary PAM
9) Obtain an expression for the probability of error M-ary PSK.
10) Obtain an expression for the probability of error of QAM
11) Relevant problems of chapter 5 of T1.
12) Briefly explain with a figure how a convolutional code with a rate Rc= k/n and constant length K is
generated. When a code is termed catastrophic?
13) A convolutional code is described by its generators g1=[11 0],g2=[1 0 1],g3=[1 1 1]. Draw the
encoder corresponding to this code and obtain the state transition and trellis diagrams. Derive its
transfer function and compute the free distance of this code. Is this code catastrophic?
14) Relevant problems of chapter 8 of T1.
15) Briefly explain the Nyquist criterion for an inter symbol interference free transmission through a
channel
16) Explain viterbi algorithm for the Discrete-Time White Noise Model.
17) Briefly explain linear transversal filter.
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 7/22
18) Briefly explain zero forcing filter.
19) Explain Mean Square Error Criterion of an equalizer.
20) Write a note on performance characteristics of the MSE Equalizer.
21) Explain the concept of Coefficiant optimization with respect decision feed back equalizer.
22) Explain Predictive decision feed back equalizer.
23) Explain Turbo equalization.
24) Relevant problems of chapter 10 of T1
25) With the aid of block diagram obtain a frequency response expression for the receiver filter that has
infinite tap equalizers for an optimum receiver and includes ISI and AWGN.
26) Describe the error metric for linear adaptive prediction and obtain expressions for an LMS algorithm
implementation. Discuss the convergence for the LMS algorithm with reference to the Mean square
error.
27) Explain with a neat block diagram the method to train an adaptive equalizer and sustain it in decision
mode.
28) Briefly explain the meaning of the terms processing gain and jamming margins with reference to
direct sequence spread spectrum signal.
29) Thirty equal power users each transmitting at a rate of 10 Kbps employ DS spread spectrum BPSK
over a shared communication channel. Ignore effect of AWGN at the receiver determine the chip rate
to obtain a Probability of error equal to 10-5.(Assume that to meet this Pe, required Eb/N0=10.0)
30) Explain slow and fast frequency hopped spread spectrum transmitters with the help of diagrams.
31) Explain the advantages of FH spread spectrum over DS spread spectrum.
32) Relevant problems of chapter 13 of T1.
33) Explain DS-QPSK modulator
34) Explain Digital cellular CDMA system based on DS spectrum.
35) With a neat block diagram explain FH spread spectrum system
36) With a neat block diagram explain independent tone FH Spread spectrum system.
37) Obtain an expression for the received output of a tapped delay line channel model for digial signaling
over a frequency selective slowly fading channel. Assuming no AWGN derive the decision variables
for binary orthogonal signaling that are detected in a RAKE demodulator
1. Derive the conditions cutoff, unsaturation and saturation region of operation a. NMOS Transistor b. PMOS Transistor
2. What do you mean by second order effects in MOS transistors Explain briefly a. Body effect b. Sub threshold region c. Channel length modulation d. Mobility variation e. Impact ionization
3. Draw and explain the DC characteristics of CMOS inverter 4. Explain the five different regions of operation 5. Explain the effect of variation of transistor dimension on DC characteristics on CMOS inverter. 6. Explain why the structures shown below cannot operate as current sources even though the
transistors are in saturation.
7. Consider the following circuit driving a capacitive load of 1pF
a. Assuming that In swings from rail-to-rail (0 to 2.5V), what is the swing on the node out? b. At the switching threshold VM = 1.75V, what is the mode of operation for M1 and M2 c. Assuming (W/L)2 = 25µm/0.25µm, determine(w/L)1 such that VM=1.75V
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 21/22
8. Explain why a. PMOS is a good conductor of logic 1 but a bad conductor of logic 0 b. NMOS is a good conductor of logic 0 but a bad conductor of logic 1
9. Explain the circuit diagrams and DC characteristics of a. Saturated load inverters b. Unsaturated load inverters
10. Draw and explain the working of CMOS Differential logic inverter. 11. Draw the
a. Schematic for static CMOS logic y =
b. Layout for static CMOS LOGIC Y = 12. Explain with the help of timing diagram the difference between flip flop and latch. 13. Draw the CMOS level diagram for a D latch and a D flip flop and explain how a D flop can be
obtained from two latches. 14. Explain the concept setup, hold time and meta stability. 15. Derive the expression for maximum combinational delay of a pipelined sequential circuit. 16. Draw the circuit of BICMOS logic and explain its working. 17. Consider the following cross-coupled complementary pass-gate logic
a. What is the logic function y implemented by the above gate? What is the voltage swing on nodes y and y‟?
b. Assume that A, A‟, B, B‟ are from ideal voltage sources and have a rail –to-rail swing (0 to VDD). Also assume (just for this part) that there is no body effect and ignore sub-threshold conduction. Is this a radioed circuit?
18. Consider the following circuit implemented using NMOS and PMOS pass transistors. Assume that the inputs and their complements (A, A‟, B, B‟) swing rail-to-rail (0 to VDD). What is the function implemented by the two circuits?
P.E.S.I.T DEPT. OF TE 1st SEM M.Tech 22/22
19. Assuming that the primary inputs (A, B, C, D) and their complements are having rail-to-rail swing (0 to VDD), what is the voltage swing on outputs Y and Z?
20. Draw the CMOS level schematic for expression y =AB+CD. Using Euler‟s path draw the layout for the logic.
21. Draw the schematic and explain the working of a. DCVSL b. C2MOS
22. Explain latch up in case of a CMOS inverter. Give various latch up prevention techniques. 23. Discuss the issues related to a dynamic CMOS design and there solutions. 24. Discuss the conduction of logic 1 and logic0 through a transmission gate. 25. Explain the working of NP Domino CMOS logic. 26. Derive the expression for small signal gain of NMOS transistor with passive load. 27. Implement y= AB+CD by using Domino CMOS structure 28. What is the Latch up effect in CMOS structure? 29. Brief about the dynamic circuit technique for overcoming the threshold voltage drops in digital
circuits. 30. Explain the static behavior of two-inverter basic bistable element. 31. Implement the CMOS negative edge triggered master slave D flip-flop 32. Explain the clocking and clock generation in digital logic 33. What is CPL logic? Write down the circuit diagram of a CPL based XOR gate. 34. Implement the CMOS TG realization of F = AB+A‟C‟+AB‟C 35. Explain basic principles of pass transistor circuits in detail 36. Explain the three stages of deleption load nMOS dynamic shift register circuit driven with two phase
clocking 37. Derive the Vth(logic threshold) of CMOS NOR2 gate. 38. What are the goals of high performance dynamic CMOS circuits? And explain about the Domino