SRM University 2007 B.Tech Electronics and Communications Engineering Bank : Microwave and Optical Communications - Question Paper

S.R.M. Institute of Science & Technology
Deemed University

School of Electronics & Communication Engineering
ques. Bank
Subject Code : EC403
Subject Name : Microwave and Optical Communications
Year & Sem : IV Year B.Tech (ECE) ,7th Sem.

Unit-I – Microwave Components and Devices
Part-A
1. What are microwaves?
2. What are the advantages and disadvantages of microwaves?
3. Give the applications of microwaves.
4. What is meant by scattering matrix?
5. What is the use of Directional Coupler?
6. Define coupling factor and directivity of a Directional Coupler?
7. What is a Circulator?
8. What is an Isolator?
9. Write the scattering matrix for an Isolator.
10. What are Avalanche transit time devices and why are they called so?
11. Define Transferred Electron Mechanism.
12. What is the difference ranging from low frequency and microwave transistors?
13. What is a TRAPATT and draw the characteristic curve.
14. What are the various modes of operation of a Gunn Diode?
15. Compare TRAPATT and IMPATT Devices.
16. What is the Scattering Matrix for N port devices?
17. What are the properties of S-Matrix?
18. Give the Scattering Matrix of E-Plane Tee and H-Plane Tee.
19. Give the S-Matrix of Magic Tee. What is the output at E arm when a1=0, a2=0, a3=a?
20. What are Reciprocal Devices? provide 2 examples.
21. What is the principle of microwave phase shifter?
22. What are non reciprocal devices? provide 2 examples.
23. Define Gunn Effect. elaborate the applications of Gunn Diode?

Part - B
1. Explain the operation of Directional Coupler with a neat diagram and derive its Scattering Matrix.
2. Explain the operation of E Plane Tee and derive its Scattering Matrix and elaborate its applications.
3. Describe the operation of Magic tee with inputs at all the arms and derive its scattering matrix. Analyse the operation under different input conditions.
4. Explain the operation of H Plane Tee and derive its Scattering Matrix. List the applications of it.
5. Explain the operation of Magic Tee. define how it can be used in constructing a Circulator and a Duplexer.
6. Explain the subsequent with scattering matrix.
1) Isolators 2) Phase Shifters.
7. Explain the construction, characteristics, configurations and parameters of microwave transistors.
8. What is a Gunn Diode? How it works as a Oscillator and discuss its characteristic curve.
9. Explain in detail, the various modes of operation of Gunn Diode.
10. Explain the operation of IMPATT Diode with its characteristics and write its applications.
11. Explain the operation of TRAPATT Diode and discuss its characteristics curve.

Unit –II – Microwave Amplifiers and Oscillators
Part - A
1. What are the limitations of conventional vacuum tubes?
2. Define velocity modulation.

Earning:   Approval pending.