8/12/2019 Question Bank for Mid Sem

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Question Bank Microwave Techniques

Ch.41.(i) Define a TEM wave.

(ii) Can a TEM wave exist in a waveguide? Justify your answer.(iii) Define dominant mode for a waveguide. Is it possi !e t"at more t"an one mode of propagation exist? #ow?

$. %ind t"e so!ution of t"e wave e&uation in re'tangu!ar 'oordinates. Exp!ain t"ree 'ases of propagation 'onstant in waveguide.

. Mat"emati'a!!y define t"e fo!!owing for t"e TE mn modes for t"e re'tangu!ar waveguideassuming proper #e!mont e&uations* (i) Cut off wave num er+ (ii) Cut off fre&uen'y+(iii) ,ropagation 'onstant+ (iv) ,"ase ve!o'ity+ (v) C"ara'teristi's wave impedan'e and(vi) -uide wave!engt".

. / for TM modes0. Exp!ain t"e asi' 'on'ept of mi'rowave

. Exp!ain w"y #+ 2and 3 parameters 'annot e measured at mi'rowave fre&uen'ies and"en'e define t"e 45parameters for a $5port networ6.7. 8"at do you understand y a Tee59un'tion?:. Exp!ain t"e fun'tioning of a waveguide Tee 9un'tion. Derive t"e simp!ified 45matrix for

t"e E5p!ane Tee ; #5p!ane Tee.

8/12/2019 Question Bank for Mid Sem

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$. Dis'uss t"e differen'es etween mi'rowave transistors and TEDs. Exp!ain t"e -unn effe't+ as exp!ained y -unn "imse!f+ drawing t"e s'"emati' diagram

for a n5type -a s diode. %or t"is diode+ draw and exp!ain(i) drift ve!o'ity of e!e'troni's vs. e!e'tri' 'urrent

(ii) Current waveform

. Exp!ain t"e B8# t"eory for -unn diode+ giving t"e 'on'ept of Differentia! egativeBesistan'e.0. Exp!ain t"e different modes of operation of a -unn Diode.. 8"i'" are t"e possi !e domain modes for t"e -unn s'i!!ation Mode. Exp!ain t"em

wit" re!evant grap"s.

Radar System M.!. S"#!$%"&

Ch.'1. 8"at do you understand y t"e term B D B and exp!ain t"e e'"o pu!se prin'ip!e.

$. Define t"e fo!!owing terms wrt radar* (i) Bange (ii) Maximum unam iguous range (iii) ,u!se repetition fre&uen'y. Draw a neat !o'6 diagram of 'onventiona! pu!se radar and exp!ain t"em in rief.. Derive t"e simp!est form of radar range e&uation t"at re!ates transmitted power , t to t"e

max. unam iguous range of radar.

Ch.(1. 8"at are t"e fa'tors affe'ting t"e radar range?$. -ive t"e radar range e&uation. 8"at s"ou!d we do to get !ong ranges? 8"at are t"e

fa'tors for fai!ure of radar e&n. to give 'orre't range?. Define minimum dete'ta !e signa!. 8it" t"e "e!p of diagram of t"e video output of radar+

exp!ain t"res"o!d dete'tion.. 8"at is a mu!tip!e time around e'"o and "ow is it re!ated wit" radar s ,B%? Considering

t"ree targets at different distan'es+ exp!ain a met"od of distinguis"ing MT e'"oes fromunam iguous e'"oes+ using 5 s'ope