Kurukshetra University 2010 B.Tech Micro wave Engineering - Question Paper
8714
BT-7/DX
MICROWAVE ENGINEERING Paper: ECE-407(E)
Option-II
Time : 3 Hours] [Maximum Marks : 100
Note : Attempt any 5 ques. by selecting at lowest 1 ques. from every part.
SECTION-I
1. (a) What do you mean by a grounded Co-planar
waveguide, define using its schematic diagram, and also discuss open and short grounded Co-planar waveguides by giving expressions of open capacitance and short end inductance respectively? 4+4+4=12
(b) For a cylindrical resonator cavity having radius three cm, length six cm, operating in TE, t j mode, the value of P' is 1.841. If skin depth is 1.53 x 10-7 cm and XQ is 10 cm then compute Q (quality factor) of resonator. 8
2. (a) discuss any 3 methods of measuring microwave
power using suitable diagrams. 4+4+4=12
(b) To measure power, measurement setup have power meter, a 22 dB coupler is used and attenuation of attenuator is eight dB. The power sensor is having VSWR at the input end as 1.52. When power meter reads 18 dBm. compute power through main arm and auxiliary arm. 4+4=8
Roll No
BT-7/DX
MICROWAVE ENGINEERING Paper: ECE-407(E) Option-II
Time : Three Hours]
[Maximum Marks : 100
Note : Attempt any five questions by selecting at least one question from each section.
SECTION-I
1. (a) What do you mean by a grounded Co-planar
waveguide, describe using its schematic diagram, and also explain open and short grounded Co-planar waveguides by giving expressions of open capacitance and short end inductance respectively? 4+4+4=12
(b) For a cylinderical resonator cavity having radius 3 cm, length 6 cm, operating in TE j mode, the value of P' is 1.841. If skin depth is 1.53 x 10-7 cm and A,Q is 10 cm then calculate Q (quality factor) of resonator. 8
2. (a) Explain any three methods of measuring microwave
power using suitable diagrams.
4+4+4=12
(b) To measure power, measurement setup have power meter, a 22 dB coupler is used and attenuation of attenuator is 8 dB. The power sensor is having VSWR at the input end as 1.52. When power meter reads 18 dBm. Calculate power through main arm and auxiliary arm. 4+4=8
3. (a) Explain importance of slow Wave structures in
Travelling Wave Tube amplifier and compare characteristics of Klystron and Travelling Wave Tube (TWT) amplifiers. 6+4=10
(b) In a two cavity klystron the gap in input cavity is 2mm. The two cavities are separated by a distance 5 cm. The beam voltage is 1000 volt and operating frequency is 8.5 GHz. Calculate Vj (voltage across cavity gap) to keep bunching parameter equals to 0.8. 10
4. (a) Why conventional Vacuum tubes are less useful at
frequencies above 1 GHz ? Give reasons to support your answer and name those tubes which can be used above I GHz. 8+2=10
(b) A TWT is having a pitch angle 5.2. The operational ' frequency is 7 GHz, if beam voltage is 1800 volt, then
calculate frequency of velocity fluctuation. 3
(c) Derive expressions for axial electric field for travelling Wave Tube. 7
SECTION-III
5. (a) Prove that for a lossless junction the product of any column of scattering matrix with the complex conjugate of any other column is zero? 10
(b) On measurement of a two port network the following scattering matrix is obtained:
0.1 Z0 0.8 Z9
0.8 Z90 0.2 Z0
Determine whether the network is reciprocal or lossless. If a short circuit is placed on port 2, what will be resulting return loss at port 1 ? 10
6. (a) What do you mean by Attenuator? Explain its basic
types using necessary diagrams and explain precision type attenuator in detail? 2+3+5=10
(b) Design a centre Bethe-hole Directional coupler with air filled rectangular waveguide of dimensions 0.9 x 0.4 inch2 at 9.8 GHz for 20 dB coupling and 40 dB directvity. 10
SECTION-IV
7. (a) Explain GUNN effect and how high field domain
formation occurs and what are the properties of this domain? 4+4+4=12
(b) A M-Si-M BARITT diode have donor concentration N = 2.8 x 1021 m~3, Si length L = 6im and Er is 11.8. Calculate breakdown voltage and breakdown Electric field. 4+4=8
8. (a) Explain physical structure, principle of operation and
plasma formation of TRAP ATT diode, with help of diagram and also explain its V-l characteristics.
(b) Explain the operation of parametric amplifiers by giving its physical description, reactance and power relations.
8714/2900/KD/2167
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| Earning: Approval pending. |
