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Maharashthra Institute of Technology,Aurangabad

LABORATORY MANUAL

Practical !"eri#ent Instruction $heet

Manual: MIT(T)/ETC/CS-I/MWOC/02

Class: BTech (ETC) DEPARTMENT: Elect!n"cs # Telec!$$un"cat"!n En%"nee"n%

&ABORATOR' :C!$$un"cat"!n Sste$ &a-I &!cat"!n:-*++ PART: I PA,E: +

MASTER LIST OF EXPERIMENT

SUB-: Microwave and Optical o!!"nication la##: BTech

$ET%

EXPERIMENT

NOEXPERIMENT NAME PAGE NO.

01 To study Microwave components.

0 !tudy o" t#e c#aracteristics o" t#e $%ystron tu&e. '

0( !tudy o" Gunn Osci%%ator 1

0) Measurement o" "re*uency o" microwave source

and demonstrate re%ations#ip amon+ "re*uency,

"ree space wave%en+t# and +uided wave%en+t#.

1-

0- Measurement o" coup%in+ "actor and directivity o"directiona% coup%er.

1'

0 Measurement o" insertion %oss and iso%ation %oss o"

t#ree port circu%ator.

1

0/ To p%ot e%ectrica% c#aracteristics o" source and

etector

)

0' Measurement o" Numerica% Aperture o" "i&er /

0 2osses measurement in optica% "i&er. (1

10 Eye pattern Measurement ()

11 3ER measurement. (/

1 isp%acement Measurement )1

PREPARED B' : MsS.Nanea APPRO1ED B': Ms1MPulan"

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Maharashtra Institute of Technology,Aurangabad

LABORATORY MANUAL


E3PERIMENT TIT&E: To study Microwave components.E3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02

Class: : BTech (ETC) DEPARTMENT: Elect!n"cs # Telec!$$un"cat"!n En%"nee"n%

&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: 2


E&peri!ent No' (

Ai!: - Ai!: To study Microwave components.

Apparat"#:- Microwave components.

T)eor*:- 1. 4ave+uide Tee 5unction6

In microwave circuit a wave+uide 7unction wit# t#ree independent port is common%yre"erred to as a tee 7unction.

a.8 E9p%ane tee :!eries tee86 An E9p%ane tee is a wave+uide tee in w#ic# t#e a;is o" its side

arm is para%%e% to t#e E "ie%d o" t#e main +uide. I" t#e co%%inear arms are symmetry a&outt#e side arm t#ere are two di""erent transmission c#aracteristics :"i+ure 1.8.It can &e

seen "rom "i+ure1.1 t#at i" t#e E9p%ane tee is per"ect%y matc#ed wit# t#e aid o" screw

tuners or inductive or capacitive windows at t#e 7unction, t#e dia+ona% e%ements o" s9

matri; :s11, s, s((8 are <ero &ecause t#ere wi%% &e no re"%ection. 4#en t#e waves are "edinto t#e side arm :port (8 t#e waves appearin+ at port1 and port o" t#e co%%inear arm wi%%

&e o" t#e same ma+nitude and opposite p#ase.

=i+1.1 E9p%ane Tee

1

=i+ 1. E =ie%ds "or various inputs

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E&peri!ent No' (

&.8 >9P%ane Tee :!#unt Tee86 A >9P%ane tee is a wave+uide tee in w#ic# t#e a;is o" its side

arm is s#untin+ t#e E9"ie%d or para%%e% to t#e >9"ie%d o" t#e main +uide as s#own in "i+ure1.(It can &e seen t#at i" t#e two input waves are "ed into port 1 and port o" t#e co%%inear arm

t#e output at port ( wi%% &e in p#ase and additive on t#e ot#er #and, i" t#e input is "ed into

port ( t#e wave wi%% sp%it e*ua%%y into port 1 and port wit# same ma+nitude and same p#ase.

=i+ure 1.( >9p%ane Tee

=i+ure 1.) E =ie%ds "or various inputs

. Ma+ic Tee :>y&rid Tee86

A ma+ic tee is a com&ination o" E9p%ane tee and >9p%ane tee.:see "i+ 1.-8.It #as

severa% c#aracteristics.I" two waves o" e*ua% ma+nitude and t#e same p#ase are "ed into port1 and port, t#e output

wi%% &e <ero at port( and additive at port ).

I" a wave is "ed into port ), it wi%% &e divided e*ua%%y &etween port 1 and port and wi%% notappear at port (.

I" a wave is "ed into port ( it wi%% produce an output o" e*ua% ma+nitude and opposite p#ase

at port 1 and port .T#e output at port ) is <ero. i.e.!)(?!()?0

I" a wave "ed into one o" t#e co%%inear arms at port 1 or port , it wi%% not appear in t#e ot#erco%%inear arm at port or port 1. 3ecause t#e E9arm causes a p#ase de%ay w#i%e t#e > arm

causes t#e p#ase advance. i.e. !1?!1?0

T#e ma+ic tee is common%y used "or mi;in+ dup%e;in+ and impedance measurementsuppose "or e;amp%e t#ere are two identica% radar transmitters, in e*uipment. A particu%ar

app%ication re*uires twice more input power to an antenna t#an eit#er transmitter can de%iver.

A ma+ic tee may &e used to coup%e t#e two transmitters to t#e antenna in suc# away t#at t#e

transmitters do not %oad eac# ot#er. T#e two transmitters s#ou%d &e connected to port ( and port) respective%y.

Transmitter 1 causes a wave to antenna "rom port 1 and anot#er to ena&%e "rom port ,

t#ese waves are e*ua% in ma+nitude &ut opposite in p#ase. !imi%ar%y transmitter connectedto port ), +ives rise to a wave at port 1 and port,&ot# e*ua% in ma+nitude @ in p#ase at

port1 t#e two opposite waves cance% eac# ot#er. At port t#e two in p#ase waves add

to+et#er. !o dou&%e output power at port is o&tained "or t#e antenna s#own in "i+ure

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E&peri!ent No' (

(8 4AEGBIE CORNER! 3EN!, AN T4I!T!6

T#e wave+uide components are norma%%y used to c#an+e t#e direction o" t#e +uide

t#rou+# an ar&itary an+%e.In order to minimi<e re"%ection "rom discontinuities it is desira&%e to #ave t#e mean %en+t# 2

&etween continuities e*ua% to an odd num&ers o" *uarter wave%en+t#.i.e 2? :nD18 +F)4#ere n? 0, 1, ........@ + is t#e wave%en+t# in wave+uide

=or wave+uide &end t#e minimum radius o" curvature "or sma%% re"%ection is +iven &y sout#

wort# as

R? 1.- & "or E &end.R? 1.- a "or > &end

4#ere a @ & are t#e dimensions o" t#e wave+uide &end as s#own in "i+.

)8 IRECTIONA2 COBP2ER!6A directiona% coup%er is "our port wave+uide 7unction as s#own in "i+ 1.'. It consists o"

primary wave+uide port1 @ port and a secondary wave+uide port( @ port ).

4#en a%% ports are terminated in t#eir c#aracteristics impedances, t#ere is "reetransmission o" power wit#out re"%ection &etween port 1 and port and t#ere is no

transmission o" power &etween port 1and port ( or &etween port @ port ), &ecause no

coup%in+ e;ists &etween t#ese two pairs o" ports.

=i+ 1. is t#e constructiona% dia+ram o" a directiona% coup%er. It consists o" main arm:Primary wave +uide8 and au;i%iary arm :!econdary wave +uide8. 3ot# are connected &y

means o" sma%% #o%es &etween ad7oinin+ wave+uide section. A num&er o" #o%es @ t#e si<e o"

t#e openin+s determine t#e amount o" power +oin+ into t#e au;i%iary. A pyramid s#apeddummy %oad is %ocated in t#e %e"t side o" t#e au;i%iary arm to a&sor&s any ener+y trave%%in+

away "rom t#e au;i%iary arm .Output e%iminatin+ re"%ection &ac$ down t#e %ine. T#e

c#aracteristics o" a directiona% coup%er can &e e;pressed in terms o" its coup%in+ "actor @ itsdirectivity.

-8 MICRO4AE I!O2ATOR6T#ere are two types o" iso%ators,

A8 =araday rotation Iso%ator 9used upto "ew 1004

38 Resonance a&sorption Iso%ator9 "or #i+# power.

T#e iso%ator is common%y used to coup%e microwave source to %oad. 3ecause o" c#an+e in %oad its "re*uency and power can &e c#an+ed due to re"%ection "rom t#e %oad. !uc#

type o" undesira&%e e""ects can &e avoided wit# t#e aid o" iso%ator in &etween source and %oad

as s#own in "i+.

A8 =araday rotation Iso%ator6 A "errite device w#ic# a%%ows unattenuated transmission in

"orward direction &ut very #i+# attenuation in reverse direction. Its construction is simi%ar tot#at o" +yrator and s#own in "i+ 1.11

4#en TE 10 wave a%%ow to pass t#rou+# R.4.G. its p%ane +ets rotated due to )- 0

twist. T#en it converted into circu%ar%y po%ari<ed TE 11 wave "urt#er wave rotate t#rou+# )-0

&ecause o" "errite in reverse direction, so output si+na% is in p#ase wit# input si+na%.

E&peri!ent No' (

4#en waves enter t#rou+# port it converts into TE11 and comes into rotation o" )-0c%oc$wise due to "errite rod. =urt#er addition )-0 c%oc$wise rotation is produced due to

twist. Now t#e way at port1 is para%%e% to t#e p%ane o" resistive card. !o a%% t#e waves are

a&sor&s &y it and no si+na%s are avai%a&%e at port 1.

Per"ormance "actors are insertion %oss o" %ess t#an 1d& and iso%ation o" 0 d& to (0 d&.

8 MICRO4AE CIRCB2ATOR6 It is a mu%tiport "errite device t#at #ave t#e property t#at

a wave incident in port1 is coup%ed in port and coup%ed in port ( on%y and so an.

A "our port circu%ator uti%i<in+ 00

non9reciproca% p#ase s#i"ter is s#own in "i+. In +enera%t#e se*uence 1 ( ) 1 is "o%%owed.

/8 =REBNCH METER6 A typica% cavity wave meter is s#own in "i+. T#e a;is o" cavity is

made perpendicu%ar to t#e main wave +uide and t#e coup%in+ "rom t#e cavity to t#e wave

+uide is ac#ieved to a sma%% circu%ar #o%e or iris. A &%oc$ po%yron :a&sor&in+ materia%8 on t#e

&ac$ o" p%un+er prevents "a%se resonance. 3y proper desi+n o" cavity t#e instrument made &ydumpin+ out any osci%%ations t#at mi+#t e;ists. It s#ou%d &e notice t#at as t#e resonance is

made sma%%er &y proper desi+n o" cavity t#e instrument may &e made to indicate wave%en+t#

direct%y on a micrometer #ead attac#ed to a p%un+er. Ca%i&ration o" t#is wavemeter is done &ydeterminin+ t#e resonant "re*uency "or di""erent micrometer settin+s. T#e ca%i&ration c#art

drawn "rom t#ese readin+s and t#e wavemter ca%i&rated accordin+%y. A si+na% is "ed to cavityt#rou+# input and detector is connected t#rou+# output.T#e si<e o" cavity is ad7usted wit# t#e p%un+er unti% t#e detector indicates t#e pronounced

osci%%ations are ta$in+ p%ace, w#ereupon "re*uency is read "rom t#e micrometer.

=i+ure 1.- =re*uency Meter

' Microwave Attenuators6 Attenuators are component t#at reduce t#e amount o" power "rom

t#e input to t#e output o" t#e device. =or #i+# powers provision must &e made to removee;cess #eat. It is important t#at attenuators reduce t#e power t#rou+# t#e device wit#out

re"%ectin+ ener+y or a""ectin+ t#e mode o" transmission.

Types o" attenuator61. =i;ed attenuator

. aria&%e attenuator

a. !%ide vane attenuator &. =%ap attenuator

c. Rotary vane attenuator

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E&peri!ent No' (

A !%ide vane Attenuator6 !%ide vane and "%ap attenuators operates on t#e princip%e t#at aresistive materia% p%aced in para%%e% wit# t#e E %ines o" a "ie%d current wi%% induce a current in

t#e materia% t#at wou%d reduce in an I R power %oss.

T#e s%ide vane attenuator is a t#in die%ectric materia% suc# as +%ass t#at is coated wit# %ossyresistive materia%. It can &e p%aced in t#e wave+uide at t#e %ocation o" ma;imum E "ie%d "or

ma;imum attenuation as s#own in "i+ure.

T#e %ocation o" t#e vane wi%% depend on t#e mode o" propa+ation in t#e wave+uide. =or a

TE10 mode t#e %ocation o" ma;imum attenuation wou%d &e in t#e center o" wave+uide.

3 =%ap attenuator6 A "%ap attenuator #as a vane t#at is dropped into t#e wave+uide t#rou+# a

s%ot in t#e top o" t#e +uide as s#own in "i+ure. T#e "urt#er t#e vane is inserted into t#ewave+uide t#e +reater t#e attenuation. T#e position o" t#e s%ot "or t#e vane must &e %ocated

wit# re"erence to t#e ma;imum E "ie%d o" t#e operatin+ mode. T#e resistive vane o" t#e "%ap

attenuator is curved to reduce re"%ections as t#e vane is inserted and removed "rom t#ewave+uide.

C Rotary ane Attenuator6 It is a precision attenuator in w#ic# attenuator "o%%ows a

mat#ematica% %aw. It #as t#ree sections eac# wit# a resistive card in t#e center as s#own in "i+

wit# a%% t#e cards %ined up t#e E "ie%d is perpendicu%ar to t#e card and t#ere is <eroattenuation. T#e center section can rotate independent%y o" t#e ends. 4#en t#e center section

is rotated t#e E "ie%d is sp%it into two components. EsinJ component is o&served &y t#e card.EcosJ sp%its into components EcosJsinJ w#ic# is o&served and EcosJw#ic# is not

o&served.EcosJ e;ist t#e attenuator wit# t#e sane attenuation as E "ie%d. T#e resu%tin+

attenuation is t#en e*ua% toAttenuation ? 0 %o+10cosJ

? )0 %o+10cosJKd&

=i+ure 1. varia&%e attenuator

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E&peri!ent No' (

etector Mount6 etection o" an e%ectroma+netic wave is accomp%is#ed t#rou+# t#e use o"

specia% diodes t#at operate t#rou+#out t#e microwave ran+e. T#ese are non9%inear devicesdesi+ned "or si+na% detection, "re*uency conversion, and "re*uency #armonic +eneration.

Microwave diodes are point contact si%icon, +a%%ium or sc#ott$y &a<<ier diodes. T#ey are

mounted in a case t#at can &e inserted into detector mount.T#ese devices cannot &e mounted across t#e end o" wave+uide or %ocated in t#e top o"

wave+uide t#is is due to mismatc# o" diode wit# t#e wave+uide and t#e re*uirement "or a

return dc current pat#. etectors are in t#e inter"aced wit# t#e wave+uides t#rou+# t#e use o"

detector mount i" t#e diode is %ocated a *uarter wave%en+t# "rom t#e end o" +uide. T#e end o" t#e +uide can &e a tunin+ p%un+er to tune out any s%i+#t mismatc#. iodes are s*uare %aw

devices on%y at %ow powers.

=i+ure1./ etector Mount

10 !%otted 4ave+uide !ection6 In s%otted 4ave+uide !ection a %on+itudina% s%ot is cut into

t#e top o" a section o" wave+uide as s#own in "i+ure. T#ese sections are used as tuners to

matc# t#e wave+uide to mismatc#ed %oad "or two ma;ima or minimum "ie%d points to &e%ocated at t#e same point. T#e s%ot must &e +reater t#an #a%" wave%en+t# "or t#e %owest +roup

wave%en+t#. =ie%d stren+t# is determined t#rou+# t#e use o" a detector pro&e t#at s%ides a%on+

t#e top o" t#e wave+uides. T#e s%ot is %ocated a%on+ t#e p%ane o" ma;imum e%ectric "ie%d "or

TE 10 mode. A sca%e is %ocated on t#e top o" t#e +uide wit# a vernier sca%e %ocated on t#ecarria+e.

=i+ure 1.'.!%otted wave+uide section =i+ 1. irectiona% Coup%er

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LABORATORY MANUAL


E3PERIMENT TIT&E: !tudy o" t#e c#aracteristics o" t#e $%ystron tu&e.E3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02




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E&peri!ent No' +

Ai!: - !tudy o" t#e c#aracteristics o" t#e $%ystron tu&e.

Apparat"#:-

L%ystron power supp%y, $%ystron tu&e wit# mount, "re*uency meter varia&%eattenuator, detector mount wit# pro&e connection, Osci%%oscope.

T)eor*:-

T#e re"%e; $%ystron ma$es t#e use o" ve%ocity modu%ation to trans"orm a continuous

e%ectron &eam into microwave power. E%ectrons emitted "rom t#e cat#ode are acce%erated and passed t#rou+# t#e positive resonator towards ne+ative re"%ector, w#ic# retards and "ina%%y

re"%ects t#e e%ectrons and t#e e%ectron turn &ac$ t#rou+# resonator. !uppose an R= "ie%d e;ists

&etween t#e resonator, t#e e%ectrons trave%%in+ "orward wi%% &e acce%erated or retarded as t#e

vo%ta+e at t#e resonator c#an+es in amp%itude. T#e acce%erated e%ectrons %eave t#e resonator

at an increased ve%ocity and t#e retarded e%ectrons %eave at t#e reduced ve%ocity. T#ee%ectrons %eavin+ t#e resonator wi%% need di""erent time to return, due to c#an+e in ve%ocities.

As a resu%t returnin+ e%ectrons +roup to+et#er in &unc#es, as t#e e%ectron &unc#es passt#rou+# resonator, t#ey interact wit# vo%ta+e at resonator +rids. I" t#e &unc#es pass t#e +rid at

suc# a time t#at t#e e%ectrons are s%owed down &y t#e vo%ta+e t#en ener+y wi%% &e de%ivered

to t#e resonator and $%ystron wi%% osci%%ate.

T#e "re*uency is primari%y determined &y t#e dimensions o" resonant cavity. >ence,

&y c#an+in+ t#e vo%ume o" resonator, mec#anica% tunin+ o" $%ystron is possi&%e. A%so a sma%%"re*uency c#an+e can &e o&tained &y ad7ustin+ t#e re"%ector vo%ta+e. T#is is ca%%ed E%ectronic

tunin+.

Proced"re:

Mode #t"d* on o#cillo#cope:

1. !et up t#e components and e*uipments as s#own in "i+ure.

. Leep position o" varia&%e attenuator at minimum attenuation position.(. !et mode se%ector switc# to =M9MO position.=M amp%itude and =M position Lno&

at mid position, $eep &eam vo%ta+e $no& "u%%y antic%oc$wise and re"%ector vo%ta+e

$no& to "u%%y c%oc$wise and &eam switc# to O== position

E&peri!ent No' +

4 Leep t#e timeFdivision sca%e o" osci%%oscope around 100 M>< "re*uency

measurement and vo%tFdiv to %ower sca%e.

5 !witc# ON t#e $%ystron power supp%y and osci%%oscope.

6 !witc# ON &eam vo%ta+e switc# and set &eam vo%ta+e to -0 &y &eam vo%ta+e

contro% $no&.7 Leep amp%itude $no& o" =M modu%ator to ma;imum position and rotate t#e re"%ector

vo%ta+e antic%oc$wise to +et modes as s#own in "i+ure on t#e osci%%oscope. T#e

#ori<onta% a;is represents re"%ector vo%ta+e and vertica% a;is represents output power.

8 3y c#an+in+ t#e re"%ector vo%ta+e and amp%itude o" =M modu%ation, any mode o"

$%ystron tu&e can &e seen on osci%%oscope

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E&peri!ent No' +

alc"lation,rap):-

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E&peri!ent No' +

irc"it .ia/ra!:-

L%ystron

powersupp%y

L%ystronMount

wit# tu&e

Iso%ator =re*uency

meter aria&%e

attenuator

etector

mount

!4R

Meter

Mu%timeter

Osci%%oscope

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LABORATORY MANUAL

Practical !"eri#ent Instruction $heetE3PERIMENT TIT&E: Stu !6 ,unn Osc"llat!

E3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02


&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: +2


E&peri!ent No' 1

Ai!: - To study 9I c#aracteristics o" Gunn diode.

Apparat"#:-

• Gunn Power !upp%y

• Iso%ator

• Gunn osci%%ator

• PIN modu%ator

• =re*uency Meter

• Matc#ed termination

• Coo%in+ =an• 3NC93NC ca&%e and TNC9TNC ca&%e.

T)eor*:-

Gunn diodes are ne+ative w#ic# are norma%%y used as %ow power osci%%ator at microwave

"re*uencies in transmitter and a%so as %oca% osci%%ator in receiver "ront ends.53 Gun

discovered microwave osci%%ation in +a%%ium arsenide :GaAs8, Indium P#osp#ide :InP8 andCadmium te%%uride :CdTe8.T#ese are semiconductors #avin+ a c%ose%y spaced ener+y va%%ey

t#e conduction &onds as s#own in "i+. "or GaAs.4#en a dc vo%ta+e is app%ied across t#e

materia%,an e%ectric "ie%d is esta&%is#ed across it. At %ow E9"ie%d in t#e materia%, most o" t#e

e%ectrons wi%% &e %ocated in t#e %ower ener+y centra% va%%ey P. At #i+#er E9"ie%d most o" t#ee%ectrons, wi%% &e trans"erred into #i+# ener+y state o" 2 and X va%%eys w#ere t#e e""ective

e%ectron mass is %ar+er and #ence e%ectron mo&i%ity is %ower t#an t#at in t#e %ow ener+y P

va%%ey. !ince t#e conductivity is direct%y proportiona% to mo&i%ity, t#e conductivity and #encet#e current decreases wit# increase in E9"ie%d or vo%ta+e in an intermediate ran+e, &eyond a

t#res#o%d va%ue vt# as s#own in "i+. t#is is ca%%ed trans"erred e%ectron e""ect and t#e device is

a%so ca%%ed Trans"er E%ectron evice:TE8 or Gunn diode. T#us t#e materia% &e#aves asne+ative resistance device over a ran+e o" app%ied vo%ta+e and can &e used in microwave

osci%%ator.

Proced"re:

• !et t#e component as s#own in "i+ure.

• Leep t#e contro% $no&s o" Gunn power supp%y as &e%ow Meter switc#99999999999999999O==

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E&peri!ent No' 1

Gunn &ias $no&99999999999999=u%%y antic%oc$wise

Pin &ias $no&99999999999999999 =u%%y antic%oc$wise

Pin mode "re*uency9999999999Any position.

• !et t#e micrometer o" Gunn osci%%ator "or re*uired "re*uency o" operation.

• !witc# ON t#e Gunn power supp%y.

• Measure t#e Gunn diode current correspondin+ to t#e various Gunn &ias

• o%ta+es t#rou+# t#e di+ita% pane% meter switc#. o not e;ceed t#e &ias

vo%ta+e a&ove 10 v• P%ot t#e vo%ta+e and current readin+s on t#e +rap# as s#own in "i+ure

• Measure t#e t#res#o%d vo%ta+e w#ic# corresponds to ma;imum current

O2#ervation:

!r No GBNN vo%ta+e:8 Current:A8

1 0 0

1 0.1)'

( 0./)

) ( 0.(0

- ) 0.(00

- 0./1

/ 0.(

' / 0./0

' 0.-

10 0./1

Re#"lt 0 oncl"#ion:-


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E&peri!ent No' 1

.

irc"it .ia/ra!:-

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LABORATORY MANUAL


E3PERIMENT TIT&E: =re*uency measurement o" Microwave source

E3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02Class: : BTech (ETC) DEPARTMENT: Elect!n"cs # Telec!$$un"cat"!n En%"nee"n%

&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: +7


E&peri!ent No' 3

Ai!:- =re*uency measurement o" Microwave source and demonstrate re%ations#ip amon+

"re*uency :"8 "ree space wave%en+t# :8 and +uide wave%en+t#:8

Apparat"#:- L%ystron power supp%y, $%ystron tu&e wit# mount, varia&%e attenuator, "re*uency meter,

"i;ed attenuator, s#ort CRO as !4R meter

T)eor*:- =or dominant TE10 mode in wave+uide c, 0 and + are re%ated &y "o%%owin+ e*uation 1F 0

? 1F + D 1F c

c ? cut o"" "re*uency 0 ? "ree space wave%en+t#

+ ? +uide wave%en+t#

=or TE10 mode, c? aFm w#erea? &road dimension o" wave+uide :.'cm o" ; &and8

Proced"re:

1. !et up t#e components and e*uipments as s#own in "i+ure.

. !et up varia&%e attenuator at minimum attenuation position.

(. Leep t#e contro% $no&s o" !4R meter as &e%owRan+e -0 d&

Input switc# Crysta% %ow impedance

Meter switc# Norma% PositionGain Mid Position.

). Leep t#e contro% $no&s o" $%ystron power supp%y as &e%ow

3eam vo%ta+e O==

Mod switc# AM3eam vo%ta+e $no& =u%%y antic%oc$wise

Re"%ector vo%ta+e =u%%y c%oc$wise

AM9 amp%itude $no& Around "u%%y c%oc$wise

AM9"re*uency $no& Around mid position.

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E&peri!ent No' 3

4 !witc# ON t#e $%ystron power supp%y, !4R meter and coo%in+ "an switc#.

5 !witc# ON t#e &eam vo%ta+e switc# and set &eam vo%ta+e at -0 wit# t#e #e%p o" &eam

vo%ta+e $no&.

6 Ad7ust t#e re"%ector vo%ta+e to +et some de"%ection in !4R meter.

7 Ma;imi<e t#e de"%ection wit# AM amp%itude and "re*uency contro% $no& o" power supp%y.

8 Tune t#e p%un+er o" $%ystron Mount "or ma;imum de"%ection.

(9 Tune t#e re"%ector vo%ta+e $no& "or ma;imum de"%ection.

(( Tune t#e pro&e "or ma;imum de"%ection in !4R meter.

(+ Tune t#e "re*uency meter $no& to +et a dip on t#e !4R sca%e and note down t#e

"re*uency direct%y "rom "re*uency meter.

(1 Rep%ace t#e termination wit# mova&%e s#ort, and detune t#e "re*uency meter.

(3 Move t#e pro&e a%on+ t#e s%otted %ine. T#e de"%ection in !4R meter wi%% vary. Move t#e

pro&e to a minimum de"%ection position, to +et accurate readin+. I" necessary increase t#e!4R meter ran+e d& switc# to #i+#er position. Note and record t#e pro&e position.

(4 Move t#e pro&e to ne;t ma;imum position and record t#e pro&e position a+ain.

(5 Ca%cu%ate t#e +uide wave%en+t# as twice t#e distance two successive minimum positiono&tained as a&ove.

(6 Measure t#e wave+uide inner &road dimension a w#ic# wi%% &e around .'mm "or ;9 &and.

(7 Ca%cu%ate t#e "re*uency &y "o%%owin+ e*uation.

" ? cF 04#ere c? (10' meterFsec.ie ve%ocity o" %i+#t.

(8 eri"y wit# "re*uency o&tained &y "re*uency meter.

O2#ervation:

3eam o%ta+e ? -0 3eam current ? mA

Repe%%ar vo%ta+e ? 9-0

Position o%ta+e:p9p8 istance:cm8

0 0 11.0

0 1 10.(

o 11.-

0 1 1.(

1 0 1(.//

1 1 1(.)(

1 1(.)

1 1 1-.0

0 1.('

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E&peri!ent No' 3

alc"lation,rap):-

+ ? :918 ? :1.(' 9 1(.// 8 ? -. cm

c ? aFm ?.)F1 ? ).' cm

1F 0? 1F +D 1F c

?.'0

0 ? (.-(-) cm

" ? cF 0 ?(10' F :(.-(-)1098? '.)' G><


irc"it .ia/ra!:-

L%ystron

Power !upp%y

L%ystronMount

wit#tu&e

Iso%ator =re*uencyMeter

aria&%eAttenuator

!%otted2ine

Tuna&%e

Pro&e

Termination

!4R Meter

Mova&%e

s#ort

7/23/2019 mwoc1



LABORATORY MANUAL

Practical !"eri#ent Instruction $heetE3PERIMENT TIT&E: T! $easue c!u8l"n% an "ect"9"t !6 "ect"!nal c!u8le



&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E:+5


E&peri!ent No'4

Ai!: -. To measure coup%in+ @ directivity o" directiona% coup%er

Apparat"#:-

• L%ystron power supp%y.

• L%ystron tu&e wit# mount.

• =i;ed attenuator "re*uency meter.

• Mu%ti9#o%e directiona% coup%er.

• Matc#ed termination.

• aria&%e attenuator.

• etector mount !4R meter.

T)eor*:- A directiona% coup%er is a device wit# w#ic# it is possi&%e to measure t#e incident and

re"%ected wave separate%y. It consists o" two transmission %ines t#e main arm and au;i%iary

arm, e%ectroma+netica%%y coup%ed to eac# ot#er. T#e power enterin+ in t#e main arm +ets

divided &etween port and ( and a%most no power comes out in port) power enterin+ at portis divided &etween port 1 and ).

T#e coup%in+ "actor is de"ined asCoup%in+ =actor:c8 ?10%o+10 PinFPau; d3?P1FP(

0%o+ inFau; d3

4#ere :d38 ?coup%in+ "actor, d3. Pin?Input power to t#e coup%er.

Pau;?power oFp o" au;i%iary arm.

4it# &ui%t in termination and power enterin+ at port 1 t#e directivity o" t#e coup%er is a

measure o" separation &etween incident wave and t#e re"%ected wave. irectivity is measuredas

:d&8 ?10%o+10 :Pau;:=orward8FPau;:reverse88?PFP1

?0%o+ :au; :"8Fau;:r88 4#ere ?irectivity o" t#e coup%er, d&

Pau; :"orward8 ? Power in t#e au;i%iary arm due to power in t#e "orward

direction Pau; :reverse8 ? Power in t#e au;i%iary arm due to power in t#e reverse

direction

E&peri!ent No'4

Proced"re:

• Arran+e t#e setup as s#own in "i+. O&tain t#e osci%%ation as descri&ed ear%ier. !ince t#e

output main arm is terminated t#eir wi%% &e no re"%ection.

• T#e power +oin+ t#rou+# au;i%iary arm can &e measured &y !4R meter. Ta$e t#e readin+

as P).

• isconnect t#e directiona% coup%er and matc#ed %oad.

•

Connect t#e mount a"ter "re*uency meter.• Measured t#e detected output. Ta$e t#is readin+ as P1.

• Ca%cu%ate t#e coup%in+ "actor in d3.

• =or directivity measurement reverse t#e direction o" directiona% coup%er and "ind out t#e

output power at au;i%iary port ca%cu%ate t#e directivity.

alc"lation,rap):-

3eam vo%ta+e ? -0v

3eam current ? mARepe%%er vo%ta+e e? 9-0v

Measurement in "orward direction

Output at port )?P)"

Input power to port1 ? P1

C :d38 ?0 %o+10 :P1FP)" 8 ?0%o+10 :iF)" 8

v)" ?10.-?0.- v

in ?1.1?1. v

C :d38 ?/.d3Measurement in reverse direction6

Output at port )? P)r in reverse direction

:d38 ?0 %o+10 :P)" FP)r 8 ?0%o+10 :)" F)r 8

)r?1-mv?10.00-?0.00-v

:d38 ?)0d3


Coup%in+ :d38 ?/.d3

irectivity :d38 ?)0d3

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E&peri!ent No'4

irc"it .ia/ra!:-

7/23/2019 mwoc1



LABORATORY MANUAL

Practical !"eri#ent Instruction $heetE3PERIMENT TIT&E: T! $easue "nset"!n l!ss an "s!lat"!n l!ss !6 thee 8!t c"culat!




7/23/2019 mwoc1


&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E:2+


E&peri!ent No' 5

Ai!:- To measure insertion %oss and iso%ation o" t#ree part circu%ator

Apparat"#:- L%ystron power supp%y, L%ystron tu&e wit# mount, "i;ed attenuator, varia&%e

attenuator "re*uency meter, circu%ator, detector mount, matc#ed %oad, CRO as !4R meter.

T)eor*:- Circu%ator is de"ined as device wit# ports arran+ement suc# t#at ener+y enterin+ at port is

coup%ed to an ad7acent port &ut not coup%ed to t#e ot#er ports. It is depicted in =i+./.

Circu%ator can #ave any no. o" ports.An iso%ator is a two port device t#at trans"ers ener+y "rom input to output wit# %itt%e

attenuation @ "rom output to input wit# very #i+# attenuation. T#e iso%ator, s#own in =i+.

can &e derived "rom a t#ree port circu%ator &y simp%y p%acin+ a matc#ed %oad :re"%ection %esstermination8 on one port.

T#e important circu%ator @ iso%ator parameters are6

A CIRCB2ATOR6 Insertion %oss is t#e ratio o" power supp%ied &y at t#e output port to

power supp%ied &y source to t#e input port, measured wit# ot#er ports terminated in t#e

matc#ed %oad. It is e;pressed in d3.

3 I!O2ATOR6 Iso%ation is t#e ratio o" power app%ied to t#e output to t#at measured at t#e

input. T#is ratio is e;pressed in d3. T#e iso%ation o" a circu%ator is measured wit# t#e t#ird

port terminated in a matc#ed %oad.

C INPBT !4R6 T#e input !4R o" an iso%ator or circu%ator is t#e ratio o" vo%ta+e

ma;imum to vo%ta+e minimum o" t#e standin+ wave e;istin+ in t#e %ine wit# a%% ports e;ceptt#e test port are matc#ed

Proced"re:

• Arran+e t#e set up as s#own in =i+.

• Put "re*uency meter and varia&%e attenuator at minimum position.

• Ad7ust t#e &eam vo%ta+e ? -0 dc.

E&peri!ent No' 5

.

• O&tain t#e rectan+u%ar osci%%ation on t#e C. R. O. screen.

• Measurement o" insertion %oss

• Arran+e t#e set up as s#own in =i+.

• Put "re*uency meter and varia&%e attenuator at minimum position.

• Ad7ust t#e &eam vo%ta+e ? -0 dc.

•O&tain t#e rectan+u%ar osci%%ation on t#e C. R. O. screen.

• Measurement o" insertion %oss.

o Measure t#e vo%ta+e present at port :8. Now disconnect circu%ator connect

detector mount to varia&%e attenuator and measure :18 ca%cu%ate.

o Insertion %oss ? 0 %o+10 :1F8 d&.

• Measurement o" Iso%ation6

Now connect circu%ator in reverse "as#ion port wit# varia&%e

attenuator, port 1 detector mount, port ( matc#ed %oad. Measure t#e

vo%ta+e present at port 1 :18 "rom t#e previous measurement.

o Ca%cu%ate Iso%ation

Iso%ation ? ? 0 %o+10 :Input FOutput8 d3

alc"lation,rap):-

1. Measurement o" insertion %oss "or circu%ator in "orward direction1? . ; 0 m vo%ts :input8

? .) ; 0 m vo%ts :output8

I2?0. d&

. Measurement o" iso%ation %oss "or circu%ator in reverse direction1? . ; 0 m vo%ts :input8

? 0.'m vo%ts :output8Iso%ation?(.- d&

(. Measurement o" insertion %oss "or iso%ator in "orward direction

1? . ; 0 m vo%ts :input8

? ))m vo%ts :output8I2?1.)- d&

). Measurement o" iso%ation %oss "or iso%ator in reverse direction

1? . ; 0 m vo%ts :input8? 0. ; 0 m vo%ts :output8

Iso%ation?./ d&

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E&peri!ent No' 5


1. Insertion %oss o" circu%ator ? 0.- d3

. Iso%ation %oss o" circu%ator 1.)- d3(. Insertion %oss o" Iso%ator ? (.- d3

). Iso%ation %oss o" Iso%ator ? ./ d3

irc"it .ia/ra!:-

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LABORATORY MANUAL


E3PERIMENT TIT&E: To p%ot e%ectrica% c#aracteristics o" source and etector E3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02

Class: : BTech (ETC) DEPARTMENT: Elect!n"cs # Telec!$$un"cat"!n En%"nee"n%&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: 2*


E&peri!ent No' 6

Ai!: - !tudy o" I c#aracteristics o" 2EFetector

Apparat"#:-

• =i&er 2in$ C

• 1- cm "i&er ca&%e

• o%tmeter

• Current meters

• 5umper to crocodi%e connectors

• Power !upp%y

T)eor*:-

In optica% "i&er communication system, e%ectrica% si+na% is "irst converted into optica% si+na%

wit# t#e #e%p o" EFO conversion device as 2E. A"ter t#is optica% si+na% is transmittedt#rou+# optica% "i&er, it is retrieved in its ori+ina% e%ectrica% "orm wit# t#e #e%p OFE

conversion device as p#otodetector .i""erent tec#no%o+ies emp%oyed in c#ip "a&rication %ead

to si+ni"icant variation in parameters "or t#e various emitter diodes. A%% t#e emitters

distin+uis# t#emse%ves in o""erin+ #i+# output power coup%ed into t#e p%astic "i&er. atas#eets "or 2Es usua%%y speci"y e%ectrica% and optica% c#aracteristics, out o" w#ic# are

important pea$ wave%en+t# o" emission, conversion e""iciency :usua%%y speci"ied in terms o"

power %aunc#ed in optica% "i&er "or speci"ied "orward current8, optica% rise and "a%% times

w#ic# put t#e %imitation on operatin+ "re*uency, ma;imum "orward current t#rou+# 2E andtypica% "orward vo%ta+e across 2E. P#otodetectors usua%%y comes in variety o" "orms %i$e

p#otoconductive, p#otovo%taic, transistor type output and diode type output. >ere a%soc#aracteristics to &e ta$en into account are response time o" t#e detector w#ic# puts t#e

%imitation on t#e operatin+ "re*uency, wave%en+t# sensitivity and responsive%y

Proced"re:-

Re"er to t#e &%oc$ dia+ram @ carry out t#e "o%%owin+ connections and settin+s.

• Connect t#e power supp%y wit# proper po%arity to t#e $it %in$9C and switc# it on.

• Leep a%% t#e switc# "au%ts in O== position.

• Leep switc# !4 towards I position.

• Leep t#e &ias pot P at ma;imum "u%%y c%oc$wise position.

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E&peri!ent No' 6

• Connect Current meters to 7umpers 5P( @ 5P).

• Connect vo%tmeter &etween 7umpers 5P1 @ 5P.

• !%i+#t%y unscrew t#e cap o" !=>/- :0nm8. o not remove t#e cap "rom t#e

connector. Once t#e cap is %oosened, insert t#e 1- cm "i&er into t#e cap. Now ti+#ten

t#e cap &y screwin+ it &ac$.

• Insert t#e ot#er end o" optica% "i&er into detector !=> -0 unti% it is seated, t#en

%i+#t%y ti+#ten t#e "i&er optic %oc$in+ cinc# nut.

• P- is used to contro% current "%owin+ t#rou+# t#e 2E to +et t#e I c#aracteristics o"

2E, rotate P- s%ow%y and measure "orward current and correspondin+ "orward

vo%ta+e t#rou+# 2E and a%so measure current t#rou+# detector, Ta$e num&er o" suc#readin+s "or various current va%ues and p%ot I c#aracteristics +rap# "or t#e 2E.

• =or eac# readin+ ta$en a&ove, "ind out t#e power, w#ic# is product o" I and . T#is is

t#e e%ectrica% power supp%ied to t#e 2E. ata s#eets "or t#e 2E speci"y optica% power coup%ed into p%astic "i&er w#en "orward current was 10mA as 00m4. T#is

means t#at t#e e%ectrica% power at 10mA current is converted into 00m4 o" optica%

ener+y. >ence, t#e e""iciency o" t#e 2E comes out to &e appro;. 1.1-Q.

• 4it# t#is e""iciency assumed, "ind out optica% power coup%ed into p%astic optica% "i&er

"or eac# o" t#e readin+. P%ot t#e +rap# o" "orward current vFs output optica% power o" t#e 2E.

• !imi%ar%y &y assumin+ t#at transmitted power reac#es receiver wit#out any %oss p%ots

t#e received power vFs receiver current

O2#ervation Ta2le:-

; $% I; $!A% Pi$!w% Po $<=% I $<A%

1.00 0.- 0.' . 0./

1.0 0.' 1.( 1-. 1./

1.)0 1.)) .(0 .) .-01.0 .() (.0 )).' 0

1.'0 (.) . /1.) (0

1./00 -.)) .(- 10/.- )-

1./0 /.) 1.'0 1)/. 0

1./)0 10.1) 1/.) 0.' '0

1./0 1(.0/ (.00 ).- 100

1./'0 1.' './ (((.1 1(0

1.'00 1.' (-./ )10. 10

1.'0 (./ )(.1( )-. 1'0

1.')0 /.) -0.)1 -/./ 00

1.'0 (0. -./ -./ 0

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E&peri!ent No' 6

=?"orward vo%ta+e o" 2E !=>/-I=?"orward current o" 2E !>=/-

Pi?I:E%ectrica% Power8

Po?Pi1.1- Q: Optica% Power o" 2E/-.8I?etector current o" !=>-0 :OFP Current.8

" s I" c#aracteristics

Responsive%y o" etector

==orward o%ta+e o" 2E !=>/-I" =orward Current o" 2E !=>/-

alc"lation,rap):-


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E&peri!ent No' 6

irc"it .ia/ra!:-

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LABORATORY MANUAL


E3PERIMENT TIT&E: Measurement o" Numerica% Aperture o" "i&er E3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02




E&peri!ent No' 7

Ai!: - Measurement o" Numerica% Aperture o" optica% "i&er.

Apparat"#:-

• =i&er 2in$ C

• ( meter "i&er ca&%e

• N.A. 5i+

• !tee% ru%er

• Power !upp%y

T)eor*:-

Numerica% aperture re"ers to t#e ma;imum an+%e at w#ic# t#e %i+#t incident on t#e"i&er end is tota%%y interna%%y re"%ected and is transmitted proper%y a%on+ t#e "i&er. T#e cone

"ormed &y t#e rotation o" t#is an+%e a%on+ t#e a;is o" t#e "i&er is t#e cone o" acceptance o" t#e"i&er. T#e %i+#t ray s#ou%d stri$e t#e "i&er end wit#in its cone o" acceptanceS e%se it is

re"racted out o" t#e "i&er core

CON!IERATION! IN NBMERICA2 APERTBRE MEA!BREMENT6

(' It is very important t#at t#e optica% source s#ou%d &e proper%y a%i+ned wit# t#e ca&%e and

t#e distance "rom t#e %aunc#ed point and t#e ca&%e &e proper%y se%ected to ensure t#at t#e

ma;imum amount o" optica% power is trans"erred to t#e ca&%e.

+' T#is e;periment is t#e &est per"ormed in a %ess i%%uminated room.

Proced"re:-

Re"er to t#e &%oc$ dia+ram @ carry out t#e "o%%owin+ connections and settin+s.

• Connect t#e power supp%y wit# proper po%arity to t#e $it %in$9C and switc# it on.

• Leep a%% t#e switc# "au%ts in O== position.

• Leep t#e 7umpers 5P1, 5P @ 5P) s#orted and 5P( towards sine position.

• Leep switc# !4 towards I position.

• Leep t#e &ias pot P at ma;imum "u%%y c%oc$wise position.

• !%i+#t%y unscrew t#e cap o" !=>/- :0nm8. o not remove t#e cap "rom t#e

connector. Once t#e cap is %oosened, insert t#e ( meter "i&er into t#e cap. Now ti+#ten


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E&peri!ent No' 7

• Insert t#e ot#er end o" t#e "i&er into t#e numerica% aperture measurement 5i+. >o%d

t#e w#ite s#eet "acin+ t#e "i&er. Ad7ust t#e "i&er suc# t#at its cut "ace is perpendicu%ar

to t#e a;is o" t#e "i&er.

• Leep t#e distance o" a&out 10mm &etween t#e "i&er tip and t#e screen. Gent%y

ti+#ten t#e screw and t#us "i; t#e "i&er in t#e p%ace.

• Now o&serve t#e i%%uminated circu%ar patc# o" %i+#t on t#e screen.

•

Measure e;act%y t#e distance d and a%so t#e vertica% and #ori<onta% diameters MR and PN.

• Mean radius is ca%cu%ated usin+ t#e "ormu%a R ? :MRDPN8F).

• =ind t#e numerica% aperture o" t#e "i&er usin+ t#e "ormu%a, NA ? sin J ma; ? r F :d

D r 8 1F 4#ere J ma; is t#e ma;imum an+%e at w#ic# t#e %i+#t incident is

proper%y transmitted t#rou+# t#e "i&er

O2#ervation Ta2le:-

alc"lation,rap):-

PN>('+c!

MR>('+c!

R>PN?MR

3

>('+?('+

3

>9'5c!d>(c!

NA>? r F :d D r8 1F

? 0.

1.1

?0.-1)


T#us we #ave ca%cu%ated t#e numerica% aperture o" optica% "i&er. T#e NFA came out to &e 0.-1).

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E&peri!ent No' 7

irc"it .ia/ra!:

7/23/2019 mwoc1



LABORATORY MANUAL

Practical !"eri#ent Instruction $heetE3PERIMENT TIT&E: Measue$ent !6 &!sses "n O8t"cal ;e



&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: <+


E&peri!ent No' 8

Ai!: - T#e o&7ective o" t#is e;periment is measurin+ %oss in t#e "i&er.

(' Propa+ation 2oss

+' 3endin+ 2oss

1' Connector 2oss

Apparat"#:-

• =C2901 @ =C290.

• 1- cm @0 Meter =i&er ca&%e.

• Patc# c#ords.

• Power !upp%y :Bse on%y one provided8.• 0 M>< ua% C#anne% Osci%%oscope

T)eor*:- Optica% "i&ers are avai%a&%e in di""erent variety o" materia%s. T#ese materia%s are usua%%y

se%ected &y ta$in+ into account t#eir a&sorption c#aracteristics "or di""erent wave%en+t#s o"

%i+#t. In case o" optica% "i&er, since t#e si+na% is transmitted in t#e "orm o" %i+#t, w#ic# iscomp%ete%y di""erent in nature as t#at o" e%ectrons, one #as to consider t#e interaction o"

matter wit# t#e radiation to study t#e %osses in "i&er. 2osses are introduced in "i&er due to

various reasons. As %i+#t propa+ates "rom one end o" "i&er to anot#er end, part o" it isa&sor&ed in t#e materia% e;#i&itin+ a&sorption %oss. A%so part o" t#e %i+#t is re"%ected &ac$ or

in some ot#er direction "rom t#e impurity partic%es present in t#e materia% contri&utin+ to t#e%oss o" t#e si+na% at t#e ot#er end o" t#e "i&er. In +enera% terms it is $nown as propa+ation

%oss. P%astic "i&ers #ave #i+#er %oss o" t#e order o" 1'0 d3FLm. w#enever t#e condition "or an+%e o" incidence o" t#e incident %i+#t is vio%ated t#e %osses are introduced due to re"raction

o" %i+#t. T#is occurs w#en "i&er is su&7ected to &endin+. 2ower t#e radius o" curvature more

is t#e %oss. Anot#er %oss is due to t#e coup%in+ o" "i&er at 2E and p#oto detector ends. 4#en%i+#t trave%s down optica% "i&ers, some o" t#e %i+#t is a&sor&ed &y t#e +%ass or p%astic. T#is

means t#e %i+#t comin+ out o" t#e end o" t#e "i&er is not as stron+ as t#e %i+#t +oin+ in to t#e

"i&er. 4#en desi+nin+ a "i&er communications system, you need to $now t#e si<e o" t#is %ossto ca%cu%ate t#e ma;imum distance t#e si+na% wi%% trave%. In t#is e;periment you wi%% try one

way o" measurin+ t#e %oss in t#e "i&er

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E&peri!ent No' 8

Proced"re:-

A6 Measurement o" propa+ation 2oss

• Ma$e connections as s#own in t#e &%oc$ dia+ram. Connect t#e power supp%y wit#

proper po%arity to 2in$9C Lit. 4#i%e connectin+ t#is, ensure t#at t#e power supp%y is

O==.

• Leep switc# !4 towards TX IN position.

• Leep 7umpers 5P1, 5P @ 5P) s#orted, 5P( towards sine

• !witc# on t#e power supp%y.

• !e%ect 100><91 L>< "re*uency ran+e usin+ switc# !41 in t#e "unction +enerator.

• O&serve t#e si+na% at !INE post o" t#e "unction +enerator on t#e osci%%oscope. Leep

t#e "re*uency at a&out 1 L>< usin+ Pot Pand amp%itude o" a&out 1vpp usin+ pot P1

• Connect t#e !INE post o" t#e "unction +enerator to t#e IN post o" t#e ana%o+ &u""er.

• Leep intensity contro% pot P- at minimum position &y rotatin+ it "u%%y in an

antic%oc$wise direction.

• Connect t#e OBT post o" ana%o+ &u""er to t#e TX IN post o" Transmitter.

• Ta$e t#e p%astic "i&er o" %en+t# 1-cm and insert one end into t#e transmitter 2E !=>

/-v unti% it is sea%ed, t#en %i+#t%y ti+#ten t#e "i&er optic %oc$in+ cinc# nut.

• Insert t#e ot#er end o" optica% "i&er into t#e detector !=> -0v unti% it is sea%ed t#en

%i+#t%y ti+#ten t#e "i&er optic %oc$in+ cinc# nut.

• O&serve t#e output si+na% at t#e out post o" t#e si+na% conditionin+ section on t#eOsci%%oscope &y ad7ustin+ t#e intensity contro% pot P- on $itS you s#ou%d +et t#e

reproduction o" t#e Ori+ina% transmitted si+na% mar$ t#is amp%itude %eve% as 1.

• Now rep%ace 1- cm "i&er &y 0 meter "i&er wit#out distur&in+ any o" t#e previous

settin+s. Measure t#e amp%itude %eve% at t#e receiver side a+ain. Hou wi%% notice t#at itis %ess t#an t#e previous one. Mar$ t#is as v.

• I" U is t#e attenuation o" t#e "i&er t#en we #ave

U d&? :10F21928%o+10:vFv1821? "i&er %en+t# "or v1

2? "i&er %en+t# "or v

T#is U is "or t#e wave%en+t# o" 0 nm.36 Measurement o" &endin+ 2oss

• Repeat a%% t#e steps 1 to 1 as a&ove.

• 3end t#e "i&er in a %oop. Measure t#e amp%itude o" t#e received si+na%.

• Leep reducin+ t#e diameter o" "i&er &end to a&out cm and ta$e correspondin+

output vo%ta+e readin+s.:o not reduce %oop diameter %ess t#an cm8

• P%ot a +rap# o" t#e received si+na% amp%itude versus t#e %oop diameter.

• As you +o on increase t#e &end diameter si+na% %osses wi%% a%so increase.

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E&peri!ent No' 8

irc"it .ia/ra!:

7/23/2019 mwoc1



LABORATORY MANUAL


E3PERIMENT TIT&E: Eye pattern MeasurementE3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02


&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E:<*


E&peri!ent No' (9

Ai!: - Eye pattern measurement usin+ "i&er optic %in$.

Apparat"#:-

• 2in$93 Lit wit# power supp%y.

• Patc# c#ords.

• 1 Meter "i&er ca&%e.

• 0 M>< ua% Trace Osci%%oscope

T)eor*:- T#e eye9pattern tec#ni*ue is a simp%e &ut power"u% measurement met#od "or assessin+

t#e data9#and%in+ a&i%ity o" a di+ita% transmission system. T#is met#od #as &een used e;tensive%y"or eva%uatin+ t#e per"ormance o" wire systems and can a%so &e app%ied to optica% "i&er data %in$s.

T#e eye9pattern measurements are made in t#e time domain and a%%ow t#e e""ects o" wave"orm

distortion to &e s#own immediate%y on an osci%%oscope.

An eye9pattern can &e o&served wit# t#e &asic e*uipment s#own in =i+. 10.1. T#e output "rom a pseudorandom data pattern +enerator is app%ied to t#e vertica% input o" an osci%%oscope and t#e

data rate is used to tri++er t#e #ori<onta% sweep. T#is resu%ts in t#e type o" pattern s#own in =i+.1., w#ic# is ca%%ed t#e eye pattern &ecause t#e disp%ay s#ape resem&%es a #uman eye. To see

#ow t#e disp%ay pattern is "ormed, consider t#e ei+#t possi&%e )9&it9%on+ NRV com&inations.

4#en t#ese si;teen com&inations are superimposed simu%taneous%y, an eye pattern as s#own in=i+. 1. is "ormed.To measure system per"ormance wit# t#e eye9pattern met#od, a variety o" word patterns s#ou%d

&e provided. A convenient approac# is to +enerate a random data si+na%, &ecause t#is is t#ec#aracteristic o" data streams "ound in practice. T#is type o" si+na% +enerates ones and <eros at a

uni"orm rate &ut in a random manner. A variety o" pseudorandom pattern +enerators are avai%a&%e"or t#is purpose. T#e word pseudorandom means t#at t#e +enerated com&ination or se*uence o"

ones and <eros wi%% eventua%%y repeat &ut t#at it is su""icient%y random "or test purposes. A

pseudorandom &it se*uence comprises "our di""erent 9&it%on+ com&inations, ei+#t di""erent (9

&it9%on+ com&inations, si;teen di""erent )9&it%on+ com&inations, and so on :t#at is, se*uences o" di""erent N9&it9%on+ com&inations8 up to a %imit set &y t#e instrument. A"ter t#is %imit #as &een

+enerated, t#e data se*uence wi%% repeat.

A +reat dea% o" system per"ormance in"ormation can &e deduced "rom t#e eye pattern disp%ay. Tointerpret t#e eye pattern, "o%%ow t#e procedure a#ead

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E&peri!ent No' (9

.Proced"re:-

• Re"er to t#e &%oc$ dia+ram @ carry out t#e "o%%owin+ connections and settin+s.

• Connect t#e power supp%y wit# proper po%arity to t#e $it %in$93 and switc# it on.

• Leep a%% !witc# =au%ts in O== position.

• Leep switc# !4' towards TX position.

• Leep switc# !4 towards TX1 position.

•

Leep switc# !410 towards EHE PATTERN position.• Leep 5umper 5P- towards D- position.

• Leep 5umpers 5P s#orted.

• Leep 5umper 5P' towards Pu%se position

• !e%ect PR3! +enerator c%oc$ at ( L>< &y $eepin+ 7umper 5P) at (L position.

• Connect t#e post ATA OBT o" PR3! Generator to IN post i+ita% &u""er.

• Connect t#e OBT post o" t#e i+ita% &u""er to t#e TX IN post.

• !%i+#t%y unscrew t#e cap o" !=>/- :0 nm8. o not remove t#e cap "rom t#e

connector. Once t#e cap is %oosened, insert t#e one meter "i&er into t#e cap. Now ti+#ten


•

Connect t#e ot#er end o" t#e =i&er to detector !=>--1 :P#oto Transistor etector8 verycare"u%%y.

• Connect detected si+na% TT2 OBT to vertica% c#anne% H input o" osci%%oscope.

• Connect C2L OBT o" PR3! Generator to EXT. TRIG. o" osci%%oscope.

• T#en o&serve EHE PATTERN &y se%ectin+ EXT. TRIG LNO3 on osci%%oscope

. alc"lation,rap):-


Eye pattern "or "re*uencies ( $><, )L< and 1' $>< were o&served. As t#e circuit =re*uency

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E&peri!ent No' (9

irc"it .ia/ra!:-

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LABORATORY MANUAL

Practical !"eri#ent Instruction $heetE3PERIMENT TIT&E: 3ER MeasurementE3PERIMENT NO : MIT(T)/ETC/CS-I/MWOC/02


&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: <


E&peri!ent No' ((

Ai!: -Mea#"re!ent o; Bit Error Rate

Apparat"#:-

• 2in$93 Lit wit# power supp%y.

• Patc# c#ords.

• 1 Meter "i&er ca&%e.

• 0 M>< ua% Trace Osci%%oscope

T)eor*:-

BIT ERROR RATE

In te%ecommunication transmission, t#e &it error rate :3ER8 is a Ratio o" &its t#at #ave errorsre%ative to t#e tota% num&er o" &its received in a transmission. T#e 3ER is an indication o"

#ow o"ten a pac$et or ot#er data unit #as to &e retransmitted &ecause o" an error. Too #i+# a3ER may indicate t#at a s%ower data rate wou%d actua%%y improve overa%% transmission time

"or a +iven amount o" transmitted data since t#e 3ER mi+#t &e reduced , %owerin+ t#e

num&er o" pac$ets t#at #ad to &e resent.

Mea#"rin/ Bit Error Rate

A 3ERT :&it error rate tester8 Is a procedure or device t#at measures t#e 3ER "or a +iventransmission. T#e 3ER, or *ua%ity o" t#e di+ita% %in$, is ca%cu%ated "rom t#e num&er o" &its

received in error divided &y t#e num&er o" &its transmitted.

3ER? :3its in Error8 F :Tota% &its transmitted8Bsin+ a &enc# test setup, t#is is easi%y measured &y means o" a comparator in w#ic# t#e

transmitted &its are matc#ed in an XOR +ate wit# t#e received &its.

I" t#e &its are a%i$e at t#e XOR +ate input w#en c%oc$ed in "rom t#e "%ip "%op, t#e output is

%ow. I" t#ey are di""erent, t#e XOR output +oes #i+#, causin+ an event count. T#e eventcounter can &e set "or various time periods. In +enera%, t#e %on+er t#e time period, t#e more

accurate t#e count.

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E&peri!ent No' ((

A random c#aracter +enerator and w#ite noise source s#ou%d &e used "or t#ese measurements

T#e num&er o" &it errors is dependent upon t#e amount o" noise enterin+ t#e system. 4#ite

noise, or &ac$+round noise, #as an avera+e or RM! va%ue t#at is e;ceeded periodica%%y &y pea$s t#at rise many times t#at %eve%. T#ese pea$s e;ist on%y "or a very s#ort period o" time.

4#en t#e pea$ e*ua%s or e;ceeds t#e si+na% %eve%, t#at is noise ener+y ? &it ener+y, t#ere is a

-0F-0 c#ance o" error. T#e pea$ time periods can &e ca%cu%ated statistica%%y "rom t#e error "unction.

In 2in$93, PR3! se*uence is +enerated &y usin+ a )9&it ri+#t s#i"t re+ister w#ose "eed&ac$ is

comp%eted &y t#e EX9OR +ate.

PRBS sequence is generated by using a 4-bit right shift register whose feedback isco!"eted by the #$-%R gate.&et 'nitia""y ())( be the 4 bit switch setting on the S*6+"ock States ,( , , ,4

/ B +( ( ) ) ( ( ( ( ) ) ) ) ( ( ) (4 ( ) ( ( )5 ) ( ) ( (6 ( ) ( ) (7 ( ( ) ( (8 ( ( ( ) (0 ( ( ( ( )() ) ( ( ( )

(( ) ) ( ( )( ) ) ) ( (( ( ) ) ) )(4 ) ( ) ) )(5 ) ) ( ) ((6 ( ) ) ( (1hus the sequence re!eats constant"y with a !eriod corres!onding to (6 c"ock states.&ength of sequence 2 raise to 4 2(6

3ow the Pseudo Rando Sequence !attern is + 2 ()()(((()))())((

E&peri!ent No' ((

PROE.URE:

• Re"er to t#e &%oc$ dia+ram @ carry out t#e "o%%owin+ connections and settin+s.

• Connect t#e power supp%y wit# proper po%arity to t#e $it %in$93 and switc# it on.

• Leep a%% !witc# =au%ts in O== position.

• Leep switc# !4' towards TX position.

• Leep switc# !4 towards TX1 position.• Leep switc# !410 towards TT2 position.

• Leep 5umper 5P- towards D- position.

• Leep 5umpers 5P s#orted.

• Leep 5umper 5P' towards Pu%se position.

• !e%ect PR3! +enerator c%oc$ at ( L>< &y $eepin+ 7umper 5P) at (L position.

• !et PR3! si+na% pattern usin+ !4/.

• Connect t#e post ATA OBT o" PR3! Generator to IN post i+ita% &u""er.

• Connect t#e OBT post o" t#e i+ita% &u""er to t#e TX IN post.

• !%i+#t%y unscrew t#e cap o" !=>/- :0 nm8. o not remove t#e cap "rom t#e

connector. Once t#e cap is %oosened, insert t#e one meter "i&er into t#e cap. Nowti+#ten t#e cap &y screwin+ it &ac$. Connect t#e ot#er end o" t#e =i&er to detector

!=>--1 :P#oto Transistor etector8 very care"u%%y.

• Connect detected si+na% TT2 OBT to 3it Error Rate event counter ATA IN post @ to

post IN o" Noise !ource.

• Connect post OBT o" Noise !ource to post RXATA IN o" 3it Error Rate event

counter

• Connect post C2L OBT o" PR3! Generator to post C2L IN o" 3it Error Rate event

counter.

• Press !witc# !411 to start counter.

•ary pot P( "or Noise 2eve% to o&serve e""ect o" noise %eve% on t#e error count.

• O&serve t#e Error Count 2E "or t#e error count in received si+na% in time 10

seconds.

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E&peri!ent No' ((

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LABORATORY MANUAL

Practical !"eri#ent Instruction $heetE3PERIMENT TIT&E: D"s8lace$ent Measue$ent




7/23/2019 mwoc1


&ABORATOR' :COMM4NICATION S'STEM &a-I &!cat"!n:-*++ PART: I PA,E: *+


E&peri!ent No' (+

Ai!: - !tudy e""ect o" %atera%, %on+itudina% and an+u%ar disp%acement

Apparat"#:-

• =C2901 @ =C290.

• =G901 wit# power ca&%e.

• 0 M>< ua% C#anne% Osci%%oscope.

• 0.- meter connectori<ed =i&er ca&%es

• Connectin+ !%eeve.

• Precision isp%acement 5i+s.

• Power supp%y :Bse on%y one provided8.

T)eor*:-

MEC>ANICA2 MI!A2IGNMENT IN =I3ER!6

Mec#anica% misa%i+nment is a ma7or pro&%em w#en 7oinin+ two "i&ers &ecause o" t#eir microscopic si<e. It resu%ts in t#e radiation %oss &ecause t#e radiation cone o" t#e emittin+

"i&er does not matc# t#e acceptance cone o" t#e receivin+ "i&er. T#e ma+nitude o" t#e

radiation %oss depends upon t#e de+ree o" misa%i+nment. T#ere are t#ree types o" mec#anica%misa%i+nments as s#own in t#e &%oc$ dia+ram. T#ese are %atera% :coa;ia%8, %on+itudina% :end

separation8 and an+u%ar. T#e %atera% misa%i+nment resu%ts w#en t#e a;es o" t#e "i&ers are

separated. T#e %on+itudina% misa%i+nment occurs w#en t#e "i&ers #ave t#e same a;is &ut #avesome +ap &etween t#eir and "aces. T#e an+u%ar misa%i+nment occurs w#en t#e "i&er end "aces

are no %on+er para%%e%. T#e most common misa%i+nment t#at occurs in practice is t#e %atera%misa%i+nment. T#is misa%i+nment reduces t#e over%ap area o" t#e two "i&er core end "aces

and conse*uent%y reduces t#e amount o" power t#at can &e coup%ed "rom on "i&er into t#eot#er. T#e power %oss due to t#is type o" misa%i+nment is usua%%y more t#an t#at due to t#e

ot#er types o" misa%i+nment In t#e case o" step inde; "i&ers, t#e %oss "rom %atera%

misa%i+nment can &e "ound &y simp%y ca%cu%atin+ t#e over%ap area o" t#e core &ecause t#eirradiance is constant over t#e "ace o" a step9inde; "i&er. T#e %oss due to %on+itudina%

misa%i+nment can &e ca%cu%ated &y comparin+ t#e area o" t#e receivin+ "i&ers wit# t#e area o"

E&peri!ent No' (+

T#e %oss "rom t#e an+u%ar misa%i+nment #as t#e same "orm as t#e %on+itudina% misa%i+nment

%oss wit# sin'F NA rep%acin+ <Fa.=or +raded inde; "i&ers, t#e ca%cu%ation is muc# more comp%icated &ecause t#e

irradiance varies as a "unction o" t#e position wit#in t#e "i&er core. In t#is e;periment "i&er %oss due to mec#anica% misa%i+nments are measured. T#e "i&er cou%d &e step inde; or +raded

inde; type. =i&er Optic 2in$s can &e used "or transmission o" di+ita% as we%% as ana%o+ si+na%s.3asica%%y, a "i&er optic %in$ contains t#ree main e%ements, a transmitter, an optica% "i&er and a

receiver. T#e transmitter modu%e ta$es t#e input si+na% in e%ectrica% "orm and t#en trans"orms it

into optica% :%i+#t8 ener+y containin+ t#e same in"ormation. T#e optica% "i&er is t#e medium,w#ic# carries t#is ener+y to t#e receiver. At t#e receiver, %i+#t is converted &ac$ into e%ectrica%

"orm wit# t#e same pattern as ori+ina%%y "ed to t#e transmitter. I" we transmit si+na% &etween

two "i&ers &y puttin+ t#em trou+# coup%in+ 5i+, dependin+ on t#e e;tent o" coup%in+ we wi%%+et appropriate si+na% at t#e detector side.

Proced"re:-

•

Re"er to t#e &%oc$ dia+ram and ma$e t#e "o%%owin+ connections.• Connect t#e power supp%y wit# proper po%arity to =C2901 and =C290.

4#i%e connectin+ t#is, ensure t#at t#e power supp%y i" O==.

• Leep t#e 7umpers 5P1s#ort "or D1, 5P towards sine wave, 5P( s#ort

"or D1 @ 5P) towards TX.

• Leep switc# !4 on =C2901 to I position.

• Leep switc# !41 in !IGNA2 !TRENGT> position on =C290.

• Leep pot P( "u%%y antic%oc$wise @ P) "u%%y c%oc$wise position.

• Connect t#e output o" P#oto iode detector post OBT to post IN o" !i+na%

!tren+t# Indicator &%oc$.

•

!witc# on t#e power supp%y.• Ta$e "i&ers o" 0.-meters %en+t# a"ter connectrori<ation as e;p%ained in E;p.No.1.

!%i+#t%y unscrew t#e cap o" 2E !=>/- :0nm8. o not remove t#e cap "rom t#econnector. Once t#e cap is %oosened, insert t#e 0.-meter "i&er into t#e cap. Now ti+#ten


• Connect 0.-meter "i&er wit# p%u+ "orm receiver to part A o" Precision isp%acement

5i+.

• Connect 0.- meter "i&er wit# p%u+ "orm receiver to part 3 o" Precision isp%acement

5i+.

• C#ec$ t#at vertica% and #ori<onta% a%i+nment is proper.

• P%ace t#e ot#er end o" t#is "i&er into P#oto iode !=>-0 o" =C290 &y s%i+#t%y

unscrewin+ t#e cap. o not remove t#e cap "rom t#e connector.• Once t#e cap is %oosened, insert t#e ot#er end o" "i&er into t#e cap. Now ti+#ten t#e cap

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E&peri!ent No' (+

.

2ATERA2 I!P2ACEMENT:

• Introduce some %atera% misa%i+nment wit# t#e #e%p o" ad7ustin+ screws. =or #ori<onta%disp%acement "i; t#e vertica% disp%acement screw !C1, ary t#e #ori<onta%

disp%acement &etween part A @ part 3 "rom 0 to mm in steps o" 0.-mm.

• =or vertica% disp%acement "i; t#e #ori<onta% disp%acement screw !C1, ary t#e vertica%

disp%acement &y ad7ustin+ screw !C &etween part A @ part 3 "rom 0 to mm in steps

o" 0.-mm.

• T#e amount o" misa%i+nment e""ect can &e o&served wit# t#e #e%p o" si+na% stren+t#

meter coup%ed into t#e second "i&er. Measure t#e detected si+na% at every step and

compare it wit# t#e ear%ier readin+. And rea%i+n t#e "i&er ends.

2ONGITBINA2 I!P2ACEMENT:

• C#ec$ t#at t#e a%i+nment o" part A and part 3 o" t#e precision 7i+ is proper, i" notma$e it proper &y ad7ustin+ appropriate screws.

O2#ervation Ta2le:-

Lateral .i#place!ent--

Sr no .i#place!ent in

!!

N9'o; LE.

/low

01 ( 1

0 )0( 1

Lon/it"dinal .i#place!ent-

!r No .i#place!ent in

!!

No' o; LE.

/low

01 -

0 1 )0( 1

E&peri!ent No' (+

.

An/"lar .i#place!ent6

Sr no .i#place!ent

in .e/ree

No' o; LE. /low

01 - )

0 10 1

0( 1- 0


Any $ind o" miss a%i+nment, w#et#er %atera%, %on+itudina% as an+u%ar introduces %os in

"i&er. >ence, t#ere s#ou%d &e minimi<ed to minimi<e t#e %osses.

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E&peri!ent No' (+

.irc"it .ia/ra!:-

7/23/2019 mwoc1


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