Answer any five questions
1. (a) Compare the relative merits of three different forms of pull-up for the inverter circuits.
What is the best choice for realization in nMOS technology ?
b) In the inverter araint, what is meant by Zp,n and Zp, d ? Derive the
required ratio between Zp.u and Zp,d it an nMOS inverter is to be driven from another inverter.
2. a) Draw the stick diagram and a
mask layout for an 8:1 nMOS inverter circuits. Both the input and output points should be on the polysilcon layer.
Explain the steps how to draw a aranic diagram from the CMOS layout.
Expalin the steps to
A particular layer of MOS circuit has a resistivity P= 1 Ohm Cm. A section
of this layer is 55mm long and 5mm wide and has a thickness of mm. calculate the resistance
from one from one end of this section to the other (along the length). Use the concept of sheet resistance Rs. What is the
value of Rs. ?
5. Discuss with a suitable example to the design of a PLA-based finite
6. Discuss in detail the general arrangement of a four-bit arithmetic
preunor and the design steps.
7. Carryout the design of a fourbit CMOS carry lookahead adder upto
stick diagram form. The determine what standard cells are needed and design a mark layout for each.
Write short notes on (any FOUR)
Floor plan layout e)Register cells.
What do you mean by noise ? Descibe various types of noise we encounter in
communication system engineering. Distinguish between Noise
Temprature and Available Power.
(b) Define noise figure. Express
the equivalent noise temperature of a cascade. Give an example of a receiving systems.
Write notes on the following
Line coder/decoder implementation.
Data communication protocol
(a) A particular InGaAsP LED emitting at 1.29mM is found to have a radiative recombination coefficient of 3 x 10-10
cm3/s, a carrier concentration of n0 + P0 cm-3 in its 1-mm-thick active region,
and a surface recombination velocity of 104 cm/s. Plot the frequency response of the relative optical output intensity
1 (w)/I0 of this LED for modulation frequencies ranging from 1-500 MHz at current densities of 0.5, 2.01 and 10.1
KA/cm2 what is the 3dB modulation bandwidth at each of these current densities.?
b) Discuss the structure of the LASER diodes and their radiation patterns.
With neat diagram explain the propagation modes in the single-mode
b) Explain vapor phase anial decomposition method of optical fiber
5. a) What do you mean by attenuation? Express the attenuation units. Distinguish
between Absorption and scattering losses and their causes.
b) Write notes on the following
ii) Optical amplifier.
Draw the schematic bloch diagram of a typical optical ]
communication system and explain.
b) Draw the block diagram of a unidirectional WDM system that combines
N independent input signals for transmission over a single fiber. Explain the principle of WDM. Also discuss how a bidirectional
WDM system is implemented.
What do you mean by a transpondor ? Explain the principle of
operation of the transponder
in connection with satellite communication system.
(b) Discuss various types of antenna systems
used in satellite
c) Distinguish between Rep aters
and Ground stations.
Write short notes on any four :
Free path space losses.
RADAR & TV
1. a) Define and explain what is meant by
i) aspect ratio
ii) interlaced scanning in a television.
b) Half-line scanning is used in all television
system – Explain.
a television system sends 25 picture per second and has a 625 lines per picture, calculate the bandwidth required for video
circuits. Assume data if required.
2) a) What is meant by VSB transmission Briefly explain how the
transmission plan is realized.
b) Describe and explain, with
block diagram, the operation of different parts of an inter-carrier type television receiver.
3. a) Give the block diagram of a TV transmitter using low level IF
b) What are the general characteristics
of camera tubes used in a TV system ? Explain the principle of operation of a videcon tube.
4. a) Explain how the chrominance and the luminance signals are
multiplexed with the monochrome video bandwidth.
b) How is antenna gain defined?
How does the folded dipole differ from dipole antenna in performance ?
State the paramentes controlling the detection range of a pulsed radar.
the expression of power density of echo signal at the radar antenna.
b) What considerations determine
the pulse width and PRF of a radar sat? Explain with illustrations.
6. Explain with block
diagram, the principle of operation of an FMCW radar, having facility for measuring both range and speed of a moving target.
State the limitations of FMCW radar.
7. a) Describe a moving target indicator radar with the help of functional
b) What is difference between
a pulsed radar and MTI? A3 GHz pulsed radar (MTI has a maximum unamoigous range of 150km. Calculate the first two blind speeds.
8. Write short notes on any four
a) Monopulse radar
b) Colour sub-carrier
c) Silicon diode array
d) False alarm
g) Blanking and Synchronising pulses.
1 (a) Explain the ioperation of the Reflex Klystron oscillatorwith the
(b) Why is the transit time
so important in this device ?
(c) Derive the expression for
the electronic admittance of a Reflex Klyastron.
2. (a) What are the major differences between the TWT and Klystron ?
Discuss the performance of TWT amplifier.
(b) Describe the principle
or operation of a TWT amplifier alongwith the analysis of Electron field interaction.
Give the constructional features of a multicavity magnetron and
describe its mechanism of oscillatioin.
(b) What do you mean by transferred
electron effect ? Describe a Gunn device and discuss about the operation.
Find an expression for the line impedance and characteristic
impedance of a transmission line.
(b) An open-wire transmission
line has R = 5W /m
= 5.2 x 10-8H/m, G = 6.2 x 10-3 mho/m,
= 2.13 x 10-10F/m
The signal frequency is 4 GHZ.
The characteristic impedance of the line.
propagation constant of the wave along the line.
normalized impedance of a load.
(iv) The reflection
coefficient at the load.
Derive the expression for the fields in a rectangular waveguide for TE
waves and the expression
for f0, b, l, u taking
into account that air conducting walls.
(b) A rectangular waveguide with air dielectric carries
TE10 mode at 9376 MHz. The internal dimension of the waveguide are icm and 22.8 cm. Evaluate the guide
wavelength and intrinsic impendence.
What is an isolator ? Explain with a neat diagram.
Explain in the following :
(i) coupling probe
(ii) coupling loops
(c) What is an attenuator ? Explain the characteristics
of wave guide attenuator.
Describe the method for measurement of Radiation pattern and gain of
(b) With a block diagram explain the operation of a
(c) Why TEM wave
can’t propagate chrough a rectangular wave guide ?
Give an overview of analog and digital data transmission.
(b) Explain the properties
of various types of transmission media. Discuss their advantages and disadvantages with regard to application.
2. (a) Elucidate the data encoding techniques. Explain some of the encoding
formats. Discuss their typical features and performances.
(b) Through public telephone
system give an example of digital and analog transmission system.
3. Draw the block diagram
of a PCM system and explain. Taking the an example of an arbitary analog time domain signal discuss the process of digitacation.
What do you mean by quantization error ? Show that the error is s2/ 12; where ‘s’ is the step size.
Write notes on the following ;
(i) Asynchronous and synchronous transmission
(ii) Full and Half duplex.
(b) Why is a stop-and-wait protocol not suitable for
satellite channels ? Explain
a sliding window protocol overcomes this problem ? Distinguish between a go-back-n sliding window protocol from the selective
What do you mean by multiplexing. Explain FDM and TDM.
(b) What is congestion ? Why
it occurs and how to avoid it.
(c) Distinguish between circuit
switching and switching network ?
Describe the architecture of a computer network with reference to the
OSI reference model.
(b) Explain the meaning of
7. Discuss the following :
(a) Protocol and architecture
(b) ATM logical connection
(d) Packet switching
8. Write short notes on any four
(b) TCP / IP protocol
(d) ASK, FSK, PSK
(e) Sliding window flow control
(g) Frame relay.