Osmania University (OU) 2006-1st Sem B.E Electronics & Tele-Communication Engineering 4/4 (E.C.E)(ester) supplementary ,il - Question Paper
B.E 4/4 (E.C.E)(I- Semester) supplementary Examination,April 2006
MICROWAVE ENGINEERING Code No. 10459/N
FACULTY OF ENGINEERING B.E, 4/4 (ECE) (I-Semester) Supplementary Examination, April 2006 MICROWAVE ENGINEERING
Time: Three Hours] [Maximum Marks: 75
Answer All questions of Part A.
Answer FIVE questions from Part B.
1. Define Group velocity, Phase velocity in a waveguide and sketch its variation with frequency. 3
2. What is optimum choice for rectangular waveguide dimensions ? Justify your answer. 2
3. Find S-parameters of circuit shown: 3
J2
4. Dominant mode is propagating in rectangular guide 2 -2 cm * 1 cm and frequency of operation is 9 -4 GHz. Find guide wavelength. 3
5. Waveguide in question4, is terminated in toad of4000. What will be the VSWR? 2
6. What is the role of velocity modulation of elections intwo cavity Klystron ? Explain. 3
7. Sketch the characteristics of varactor diode and explain the same. 2
8. Give reasons for variation of gain with frequency in TWT amplifier. 3
9. What are applications of IMPATT Diode in Microwave Circuits ? 2
10. Name the dominant mode in parallel plate, rectangular waveguide and circular waveguide. 2
11. Derive the field expressions for TE modes in parallel plate guide. 10
12. (a) Find the resonant frequency of Cavity Resonator of principle mode with dimensions a=2 cm,
b = 1 cm, c = 2 cm (length). 4
(b) Justify that TE,, mode is die dominant mode in circular waveguide. 3
(c) Why TEM mode cannot propagate in rectangular waveguide ? 3
13. (a) Derive the S Matrix of a Directional coupler. 6 (b) Explain the working principle ofwaveguide attenuator. 4
14. Describe the interaction in Multi Cavity Magnetron. What is rc mode ? What are the methods of separation of n mode from other modes ? Sketch the characteristics ofMagnetron. 10
15. (a) Explain the working of PIN diode and its application in Microwave Test Bench. 4
(b) How IMPATT diode can be used as oscillator ? 3
(c) What is transferred electron effect ? 3
16. (a) What is the effect of grid interception of beam cuirent ? 4
(b) What is frequency pulling and frequency pushing ? 3
(c) What is the role of slow wave structure in TWT ? 3
17. (a) Explain the working of a 4 port circulator with a neat sketch. 5 (b) Describe admittance spiral of Reflex Klystron and explain how oscillations are sustained in Klystron
Oscillator. 5
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| Earning: Approval pending. |
