Reg. No. :

M.E. DEGREE EXAMINATION, APRIL/MAY 2011

Second Semester

Communication Systems

CU 9223 — MICROWAVE INTEGRATED CIRCUITS

(Regulation 2009)

Time : Three hours Maximum : 100 marks

Answer ALL questions

PART A — (10 × 2 = 20 marks)

1. List out four substrates along with their dielectric values.

2. What are the advantages of MMIC technology?

3. Why lumped components are not realizable at microwave frequencies?

4. Write down the various approximation techniques to perform a filter

design.

5. Why matching is essential?

6. List out the gain formulas to calculate the gain of amplifier circuit.

7. Define conversion loss.

8. Draw the Leeson's model.

9. What is cryogenic effect?

10. What is reconfigurability?

Question Paper Code : 77699 303 303 303

77699 2

PART B — (5 × 16 = 80 marks)

11. (a) Compare and contrast various MMIC technology with the conventional technologies. (16)

Or

(b) (i) Explain multichip module technology. (10)

(ii) Write down the various design methodologies to design active devices. (6)

12. (a) A microstrip line is composed of zero thickness copper conductors on

a substrate having 0005.08tan,4.8 ==∈r and thickness 2.4 mm. If the

line width is 1 mm and operated at 10 GHz, calculate

(i) The characteristic impedance

(ii) The attenuation due to conductor loss.

Or

(b) Design a stepped impedance low pass filter having a cutoff frequency of 4 GHz and a fifth order, 0.5 dB equal ripple response.

Assume = Ω=Ω= 15,1000 lZR and Ω= 200hZ .

13. (a) Explain using flow chart how an amplifier can be designed at microwave frequencies.

Or

(b) The S parameters for the HP HFET – 102 GaAS FET at 2 GHz with a

bias voltage 0=gsV are given as follows )50( 0 Ω=Z

oo 6.123122.3,6.60894.0 2111 =−= SS ; ;4.62020.012o∗

=S

o6.27781.022 −=S . Determine the stability of the transistor by

calculating K and .|| ∆

14. (a) Explain the working of a single ended mixers.

Or

(b) Using one port negative resistance concept, explain the working of an oscillator.

15. (a) What are micromachined Antenna? How reconfigurability can be achieved using micro machining technique?

Or

(b) How probe station can be used to measure a RF amplifier? Write down the initial setup to perform the measurement.

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