Reg No.:_ Name:

G192117 Pages:2

APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY

SEVENTH SEMESTER B.TECH DEGREE EXAMINATION(R&S), DECEMBER 2019

Max. Marks: 100

1 a)
b)
2 a)
b)
3 a)
b)
4 a)
b)
5 ஐ
b)
6 a)

Course Code: EC461
Course Name: MICROWAVE DEVICES ANDCIRCUITS

PARTA

Answer any two full questions, each carries 15 marks.
What are the limitations of conventional solid state devices at microwaves ?
What does IMPATT diode stands for and with neat diagram explain the
construction and working of it and derive power and efficiency of the same. ?
E xplain GaAs MESFET with structure and principle of operation? Why GaAs
MESFETs are preferred over Si MESFETs ?
Discuss different biasing techniques used for microwave bipolar transistor ?
Explain one port negative resistance oscillator ?

A typical n-type GaAs GUNN diode has the following parameters

Threshold field ட = 2800 V/cm
Applied field E = 3200 V/cm
Device length L =10um
Doping concentration no = 2*104/em*
Operating frequency = 10 GHz

a) Compute the electron drift velocity
b) Current density
c) Negative electron mobility
PART 13
Answer any two full questions, each carries 15 marks.

Find the ABCD matrix coefficient computation of a transmission line section with

characteristic impedance ‘Z,’ propagation constant "0' and length ۹۶

Discuss the working of quarter wave transformer and halfwave
Explain the working of single stub tuning ?
Discuss in detail about impedance and frequency scaling

List the Kuroda’s identity.

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Duration: 3 Hours

Marks

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