Jaypee Institute of Information Technology (JIIT) 2008 M.Tech Electronics and Communication Engineering Test 3 : Photonics & Microwave Devices for ECE - Question Paper
JAYPEE UNIVERSITY OF INFORMATION TECHNOLOGY WAKNAGHAT TEST III (MAY 2008)
B.TECH.(VH SHM.), M.TECH.
COURSE CODE: PH 608 MAX. MARKS: 30
COURSE CREDITS 3 MAX. TIME: I HR 30 MIN.
COURSE NAME: PHOTONICS AND MICROWAVE DEVICES
Mole: All the questions are compulsory
SECTION A
Q.l Explain the following in brief (2 marks each)
I.' Gradient, divergence and curl of a Held.
II. Uniqueness theorem.
III. Radiative and nonradiative transitions in a semiconductor.
IV. Power conversion efllcienc> of an IMPATT diode.
SECTION B
Each question carries 4 marks
Q.2 Using Maxwells 2*1 and 4 equations derive Poynting's Theorem. Interpret ihe tenns involved.
Q_J Explain the term Varactor diode. Draw the equivalent circuit of a packaged reverse biased p-n junction varactor diode and find the quality factor and the intrinsic cul off frequency for the same.
Q.4 Diaw the typical electron-holc distribution in the various regions of p-in diode under forward bias condition. Also by solving the ambipolar transport equation in the i-regkw with appropriate boundary conditions show that the diode current is given by
1 n,2*rj
Q.5 What do you mean by barricr-injection transit time? Draw the energy band diagram of a reverse biased MSM structure with dc bias higher than Vpr but lower than Vpe
Each question carries 3 marks
Q.6 Consider a Silicon IMPATT diode with the width of avalanche region xj ~ /j, 200mA, saturation velocity Vj 107 cm sec*1, A 10-J m\ and a,a 0.5 V1. Calculate the inductance La and capacitance Ca of the avalanche region.
Q.7 A silicon n*-p junction solar cell with a 2 cm2 surface area and N, * 1019 cm'1 in the base region. Neglecting the contribution of the contribution of n region and assuming D m 50 cm: sec'1, f.= 3 n sec, and Gi * 5 * 10 cm* sec'1. Calculate Ii and VM.
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| Earning: Approval pending. |
