ANALOG COMMUNICATION LAB MANUAL - Ammini … 408(P)_ Analog... · Department of Electronics and Communication Engineering EC 09 408(P) ANALOG COMMUNICATION LAB MANUAL DEPT. OF ELECTRONICS

Department of Electronics and Communication

Engineering

EC 09 408(P)

ANALOG COMMUNICATION LAB

MANUAL

DEPT. OF ELECTRONICS & COMMUNICATION ENGINEERING

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ANA

Dep

D

DE

ALOG COMM

pt of ECE

Depart

ANA

EPT. OF

MUNICATION

tment o

ALOG

ELECTR

N LAB MAN

of ElecEn

EC

G COM

M

RONICS &

NUAL

ctronicsnginee

C 09 40

MMUN

MANU

& COMM

s and Cring

08(P)

NICA

UAL

MUNICA

Commu

ATION

TION EN

unicati

N LAB

NGINEER

1

Page 1

ion

RING


ANA

Dep

EX

Cy

Cy

ALOG COMM

pt of ECE

XPERIM

ycle 1: 1. A

2. A

3. A

4. F

5. I

6. S

cle 2:

7. F

8. F

9. B

10. P

11. P

12. P

13. P

MUNICATION

MENT LI

AM MOD

AM DETE

AM USIN

FREQUEN

IF TUNED

STUDY O

FM MOD

FM DEMO

BALANC

PULSE A

PULSE W

PULSE PO

PWM AN

N LAB MAN

IST:

DULATOR

ECTOR.

NG AD 63

NCY MIX

D AMPLI

OF PLL.

DULATOR

ODULTO

ED MOD

MPLITU

WIDTH M

OSITION

ND PPM G

NUAL

R.

3 IC.

XER.

IFIER.

R USING

OR USIN

DULATO

UDE MOD

MODULA

N MODUL

GENERA

G 565 PLL

G 565 PL

R.

DULATO

TOR USI

LATOR U

ATION US

L.

LL.

OR.

ING 555.

USING 55

SING OP

55.

-AMP.

2

Page 2


ANA

Dep

Exp

Dat

AIM

from CO

TH

AM

VA

may

tran

carr

ALOG COMM

pt of ECE

p No:1

te:

M:

To desim the observ

OMPONETransis

Capacit

Resisto

DC Sou

Interme

Signal G

Bread B

CRO

HEORY: Amplitu

MPLITUDE

LUE of the

Carrier

y be high fr

nsmitted in

rier remains

MUNICATION

ign and setuved output.

ENTS ANDtor - BF

tors - 0.

rs - 4.8

urce Voltag

ediate Frequ

Generator

Board

ude modula

OF THE

Modulating

signal is a f

requency w

the form o

s the same T

AM = A

= V

= V

N LAB MAN

AM M

up an Ampli

D EQUIPF194,

1µF, 0.01µF

8 kΩ, 48 kΩ

e - (0 – 1

uency Trans

ation may b

CARRIER

g or Base B

fixed freque

while the mo

of amplitud

The time var

AC (t) + Am (

VC (1+µ Sin

VC Sin ωct +

NUAL

MODUL

itude Modu

PMENTS

F,

Ω, 72 kΩ,

5) V

sformer

be defined

is made p

Band Signal.

ency signal

odulation si

de variation

rying ampli

(t)

ωmt) Sin ωc

(µVC÷2) C

LATOR

lator and m

REQUIR

as a system

proportiona

.

with freque

ignal is aud

n, while the

itude is calle

ct, where µ

os (ωc-ωm)

measure the m

RED:

m in which

al to the IN

ency ωc. In p

dio. In AM

e phase and

ed the enve

= Vm ÷ VC

t - (µVC÷2)

modulation

THE MAX

NSTANTAN

practice, the

,the inform

d frequency

lope of AM

) Cos (ωc+ω

3

Page 3

index

XIMUM

NEOUS

e carrier

mation is

y of the

M.

ωm) t


ANA

Dep

freq

pair

freq

belo

abou

wav

anti

Inde

Mak

wav

with

clas

with

and

BF1

of tr

PR

ALOG COMM

pt of ECE

The spe

quency, whe

r n=1.For +

quency ωc i

ow ωc is kno

Modula

ut an unmo

veform (as s

Since t

icipated tha

ex. The tota

king the cu

ves. This pro

h a tuned ci

ss C amplifi

h any of the

In orde

0.01µF (w

194. Here u

ransistor. So

ROCEDUR

1. Check

circuit o

2. Note do

3. Feed th

MUNICATION

ectrum of A

ere as the s

+ve frequen

s known as

own as the l

ation Index

odulated m

seen from th

µ =

the amplitu

at the total p

al power in t

Pt =

urrent pulses

ocess is kno

ircuit, whos

ier proportio

e dc supply v

r to genera

which provid

using capaci

o this modu

RE:

the compon

on a breadb

own the amp

e modulatin

N LAB MAN

AM contain

ideband fre

ncy the ba

s the upper

lower side b

is defined

maximum ca

he oscillosc

(VMAX - VM

ude of sid

power in th

the modulat

= (V2carr ÷ R)

s proportion

own as the f

e Q is not t

onal to the m

voltages for

ate the carri

des the Fee

itive couplin

ulation meth

nents using

oard.

plitude of c

ng signal to

NUAL

ns three ter

equency is d

and of freq

side band

band (fC - fm

as the mea

arrier (µ =

ope) can be

MIN) ÷ (VMA

debands dep

he modulate

ted wave w

) + (V2LSB ÷

nal to the m

flywheel eff

too low. It i

modulating

r the amplif

er, we use

ed Back); si

ng the mess

hodology is

g Intelligen

arrier signa

the Base te

rms. Two p

defined by f

quencies tha

(fC + fm), w

m). And the

sure of the

Vm ÷ VC)

e calculated

AX + VMIN).

pends on

ed power w

will be

÷ R) + (V2US

modulating

ffect of the tu

s possible t

voltage by

fier.

the Interme

ince they o

sage signal

also called

ce Meter o

al.

erminal of tr

pairs of sid

fSB = fC ± n

at is lying

where as sy

bandwidth

extent of a

. The modu

by using th

the modul

will depend

SB ÷ R) (rms

voltage, we

uned circuit

o make the

applying th

ediate Frequ

oscillate nea

is applied t

Base Modu

or Multi M

ransistor.

debands and

nfm and in

above the

ymmetrical

of AM is 2

amplitude v

ulation Ind

he formulae

lation index

on the mod

s).

e can gener

t, and it wo

output curr

his voltage i

uency Tran

ar 455 kHz

o the base t

ulation.

Meter and se

4

Page 4

d carrier

the first

e carrier

portion

ωm.

variation

dex of a

x, it is

dulation

rate AM

orks best

rent of a

in series

nsformer

we use

terminal

etup the


ANA

Dep

CIR

ALOG COMM

pt of ECE

4. From C

maximu

5. Calcula

6. By vary

7. Note do

8. Repeat

9. Plot the

RCUIT D

MUNICATION

CRO note do

um and min

ate the modu

ying the amp

own the amp

the experim

e output for

DIAGRAM

N LAB MAN

own the VM

nimum ampl

ulation Inde

plitude of m

plitudes VM

ment by vary

µ=1, µ>1, a

M:

NUAL

MAX and VMI

litudes of A

ex using (V

message sign

MAX and VMI

ying the fre

and µ<1 on

IN values, wh

AM signal in

VMAX - VMIN

nal, observe

IN for µ=1 a

quency of m

n a graph she

here as VMA

n +ve direct

N)/ (VMAX +

e over modu

and µ>1.

message sig

eet.

AX and VMIN

tion.

VMIN).

ulation on C

gnal.

5

Page 5

N are the

CRO.


ANA

Dep

DE

Des

Des

ALOG COMM

pt of ECE

ESIGN:

Take VC

Therefo

From ci

sign of Cap

XC1 ≤ R

XC1 ≤ 9

XCE ≤ R

CE ≥ 0.0

sign of CC1,

XC ≤ Ri

Rin = R

Xc ≤ 0

Cc ≥ 1

Cc ≥ 0

Use 0.

MUNICATION

CC = +15 V,

ore IB = 10 µ

RE = (VRE ÷

VR2 = (VRE

VR1 = (VCC

ircuit diagra

VR1 = 10IB

=> R1 = 12

=> R2 = 2.2

pacitors:

Rin/10, Rin =

1.4 , C1≥ 0

RE/10 = 9.15

02 µF , CC2:

in/10

R1R2(1+

0.123K

1/(2пf*(0.1

0.133*10-6

1 µF

N LAB MAN

IC =1 mA,

µA, VCE = 4

÷ IC) = 1.5 k

E + VBE) = 1

C – VR2) = 1

am, we have

* R1

.8 ÷ (10 * 1

2 ÷ (9 * 10 *

=R1R2(

.34 use 0.22

5

+hfe*re)

12*103)) 6

NUAL

ß=100.

0% of VCC =

kΩ since IE ~

.5+0.7 = 2.

5 – 2.2 = 12

e

& VR2

10 * 10-5) =

* 10-5) = 10

(1+hfe*re) =2µF

= 6 V, VRE

~ IC.

2V.

2.8V.

2 = 9IB * R2

51.62 kΩ.

0 kΩ.

= 91.4

= 10% of V

2

VCC = 1.5 V.

6

Page 6

.


ANA

Dep

EX

DE

RE

ALOG COMM

pt of ECE

XPECTED

EMONSTR

ESULT:

1. Modula

2. Over m

MUNICATION

D WAVEF

RATION

ation Index

modulation is

N LAB MAN

FORM:

N OF AM

s seen on C

NUAL

RO and the

e observed v

value is µ

=

=

7

Page 7


ANA

Dep

VIV

ALOG COMM

pt of ECE

VA VOCE

1. Give th

2. Give th

SSB filt

3. Define

4. Explain

5. What ar

6. What is

7. Compar

8. What ar

9. Define

10. Explain

11. Which m

MUNICATION

E:

he difference

he applicatio

ters?

ISB system

n Quadratur

re the virtue

s Lincompex

re AM, DSB

re the disad

pilot carrier

n Costas rec

modulation

N LAB MAN

e between lo

ons of SSB m

ms?

re Amplitud

es and limit

x? Could it

BSC, SSBS

dvantages of

r?

ceiver?

n technique i

NUAL

ow level mo

modulation

de Multiplex

tations of AM

be used wit

SC?

f J3E with r

is used for s

odulation an

n technique?

xing?

M?

th any form

respect to A

speech trans

nd high leve

? Give name

m of SSB sys

A3E?

smission?

el modulatio

es of 3 type

stems?

8

Page 8

on?

s of


ANA

Dep

Exp

Dat

AIM

CO

TH

sign

the

In a

by i

call

Squ

with

the

achi

in o

outp

env

ALOG COMM

pt of ECE

p No:2

te:

M: To desi

OMPONETransist

IFT

Capacito

Signal g

Bread b

D.C vol

CRO.

HEORY: The pro

nal is called

process by

amplitude m

instantaneou

ed demodu

uare –Law d

Diode d

h large carri

circuit, whi

ieves this by

only one dir

put. If the d

elope is use

MUNICATION

ign and setu

ENTS ANtor

ors

generator

oard

ltage source

ocess of ext

d demodulat

which the m

modulation (

us amplitud

ulators or d

detectors and

detector met

ier are detec

ich extracts

y simply re

rection, giv

detector is to

ed, either w

N LAB MAN

AM

up an AM de

ND EQUIP

e

tracting a m

tion or dete

message is

(AM) the in

de of modul

detectors. A

d Envelope

thod is the

cted by usin

s the envelo

ctifying the

ving either t

o be used on

will work or

NUAL

M DETEC

etector circu

PMENTS

modulating

ection. In o

recovered f

nstantaneou

lating voltag

AM detecto

detectors o

simplest m

ng the enve

ope which i

e signal. Cur

the positive

nly for dete

r equally w

CTOR

uit.

S REQUIR

or base ban

ther words,

from the mo

s amplitude

ge..The dev

ors or dem

or diode dete

method for A

lope detecto

is the base b

rrent is allo

e or negativ

ection it doe

well. The cir

RED:

nd signal fr

, demodulat

odulated sig

e of the carr

vices used f

modulators a

ector AM demodu

or. The env

band or mo

wed to flow

ve half of t

es not matte

rcuit consist

rom the mo

tion or dete

gnal at the r

rier signal i

for demodul

are categor

ulation. AM

velope detec

odulating sig

w through th

the envelop

er which hal

ts of a capa

9

Page 9

odulated

ection is

receiver

s varied

lation is

rized as

M signal

ctor uses

gnal. It

he diode

pe at the

lf of the

acitor at


ANA

Dep

the

outp

also

dem

env

mod

suit

effe

prop

chea

This

to b

suff

just

mt

PR1.

c

2. S

c

3. O

ALOG COMM

pt of ECE

output. Its

put. The val

o a leakage

modulator ci

elope.

The dio

dulation lev

able for hig

ects of fadin

pagation ma

. The m

ap. Just one

s simple typ

be an accur

fers from th

An enve

responds t

t≤-1—to av

ROCEDURSetup the

components

Setup the c

circuit.

Observe the o

MUNICATION

purpose is t

lue is chose

path to en

ircuit is con

odes can i

vels are kep

gh quality a

ng experienc

ay be such t

main advanta

e diode, one

pe of AM d

rate represe

e problems

elope detec

o the +ve p

void this pr

RE: circuit of

s.

ircuit of A

output wave

N LAB MAN

to remove a

en so that it

nable the ca

nnected may

introduce a

pt low. As

applications

ced on shor

that certain

age of this f

e capacitor

demodulator

ntation of t

known as R

tor can't kn

peaks of the

roblem.

AM GEN

AM DETEC

eform on a

NUAL

any radio fr

t does not a

apacitor to d

y provide th

appreciable

a result the

s. Additiona

rtwave broa

small band

form of AM

and one res

r isn't any g

the original

Ripple and N

now that the

e inverted m

NERATION

CTION and

CRO screen

requency co

ffect the au

discharge, b

his.The outp

e levels of

ese detector

ally these d

adcast transm

s of the sign

M demodulat

sistor are re

good if we

l modulatin

Negative Pe

e carrier ph

modulated c

N after ver

feed the A

n.

omponents

udio base ba

but the circ

put is propo

f harmonic

rs can neve

detectors are

missions. H

nal are remo

tor is that it

equired. So

want the re

ng waveform

eak Clippin

hase has bee

carrier. 1 +

rifying the

AM signal t

P

of the signa

and signal. T

cuit into wh

ortional to th

distortion

er provide a

e susceptibl

Here the ion

oved.

t is very sim

it is used s

ecovered wa

m. The circ

g.

en altered, h

mt ≤ 0

condition

to the inpu

10

Page 10

al at the

There is

hich the

he input

n unless

a signal

le to the

nosphere

mple and

so often.

aveform

cuit also

hence it

— i.e.,

of the

ut of the


ANA

Dep

CIR

DE

freq

Tak

Let

EX

ALOG COMM

pt of ECE

RCUIT D

ESIGN:

The tim

quency.

RC>> t

ke RC= 100

RF=500 KH

XPECTED

MUNICATION

DIAGRAM

me constant

time period

0T where

Hz, C1=. 01

D WAVEF

N LAB MAN

M:

t RC must

of RF

T=1/RF

1microfarad

FORM:

NUAL

be larger th

d, then R1=2

han the per

20K (use 22

riod of the

2k standard

P

lowest AM

d)

11

Page 11

M signal


ANA

Dep

RE

obse

VIV

ALOG COMM

pt of ECE

ESULT: The AM

erved on CR

VA QUES1. What ar

2. Draw th

3. What is

4. What is

5. Why do

envelop

6. Define

7. What is

8. What is

9. Discuss

10. Discuss

MUNICATION

M de-modul

RO.

STIONS:re the drawb

he frequenc

s square law

s broadband

oes the qual

pe detector?

selectivity,

s delayed A

s VSB? Wh

s bandwidth

s high level

N LAB MAN

lator circuit

backs of en

y spectrum

w demodulat

d spectrum?

lity of the de

?

sensitivity,

GC?

ere is it use

h requiremen

and low-lev

NUAL

is designed

nvelope dete

of AM wav

tor?

etected sign

and fidelity

ed?

nts of AM a

vel modulat

d and setup.

ector?

ve?

nal depend u

y of a receiv

and FM.

tion system

The output

upon RC tim

ver.

ms.

P

t waveform

me constant

12

Page 12

s are

t of an


ANA

Dep

Exp

Dat

AIMTo

COAD

Sign

CRO

Bre

cap

THAM

mul

com

FUCon

in f

volt

mul

The

sum

outp

rela

ALOG COMM

pt of ECE

p No:3

te:

M: study IC 63

OMPONED 633,

nal generat

O,

eadboard

pacitors

HEORY: M is genera

ltiplier ICs

mponents.

UNCTIONnsider the f

figure.The

tage to cu

ltiplying co

e sum of

mming node

put voltage

ation betwe

MUNICATION

AM USI

33 and to d

ENTS AND

tors,

ated by mu

s AD633 i

NAL DESfunctional b

differentia

urrent conv

ore.A burie

(X+Y)/10+

e Z allows

e to a curren

en inputs a

N LAB MAN

ING MU

esign Am

D EQUIP

ultiplying t

is used to

CRIPTIOblock diagr

l X and Y

verters.The

ed zener re

+Z is then

the user to

nt, and con

and outputs

NUAL

ULTIPLI

generator u

PMENTS

the base ba

o generate

ON: ram of the

Y inputs are

product o

eference pr

n applied t

add two o

nfigure vario

are express

IER IC

using them.

REQUIR

and signal

the Am s

four quadr

e converte

of these cu

rovides an

to the out

or more mu

ous analog

sed as:

AD633

.

RED:

by the car

signal with

ant multipl

d to differ

urrents is

overall sca

tput amplif

ltiplier out

g computati

P

rrier signal.

hout any e

lier AD633

rential curr

generated

ale factor o

fier.The am

tputs, conv

ional functi

13

Page 13

.Analog

external

3 shown

rents by

by the

of 10V.

mplifier

verts the

ions.the


ANA

Dep

The

side

side

PR1.Se

10

2. S

ou

CIR

ALOG COMM

pt of ECE

e carrier an

e-band sign

e band sign

ROCEDURet up the A

0Vpp, 1kH

Set the AM

utput and m

RCUIT D

MUNICATION

nd modulati

nal.The carr

nal to produ

RE: AM-SC circu

z modulatin

with carrie

measure the

DIAGRAM

N LAB MAN

ion inputs

rier is fed t

uce a double

uit and feed

ng signal. O

er circuit by

e modulatio

M:

AM

NUAL

to the AD6

to the Z inp

e side band

d the 20Vpp

Observe the

y modifying

on index.

M USNIG A

633 are mu

put where i

d with carrie

p,10kHz si

e output wa

g the previo

AD 633

ultiplied to

it is summe

er output.

ne wave ca

aveform

ous circuit.

P

produce a

ed with the

arrier signal

Observe th

14

Page 14

double

double

l and

he


ANA

Dep

AM

AM

ALOG COMM

pt of ECE

M-DSB-SC

M-DSB

MUNICATION

C

N LAB MANNUAL

P

15

Page 15


ANA

Dep

OU

ALOG COMM

pt of ECE

UTPUT W

MUNICATION

WAVEFO

N LAB MAN

Pi

RMS:

NUAL

nout of A

AD633

P

16

Page 16


ANA

Dep

RE

wav

ALOG COMM

pt of ECE

ESULT:

The AM

veforms are

MUNICATION

M DSB SC

observed o

N LAB MAN

circuit is de

on CRO.

NUAL

esigned and

d setup USINNG AD633

P

IC. The ou

17

Page 17

utput


ANA

Dep

Exp

Dat

AIM outp CO

TH

rece

high

this

low

by l

mix

incl

freq

PR

ALOG COMM

pt of ECE

p No:4

te:

M To desi

put frequenc

OMPONE IFT, Tr

Resisto

Capacit

Signal g

Breadbo

DC Sup

CRO.

HEORY Tuned r

eivers. In TR

her frequen

, super hete

w frequency

locally gene

xer is that w

luding orig

quencies. A

ROCEDUR

1. Set up t

2. Switch

MUNICATION

FREQ

ign and set ucy of 455 kh

ENTS & E

ransistors,

rs,

tors,

generator,

oard,

pply &

radio freque

RF receiver

cies, these r

erodyne rece

called inter

erated frequ

when two sig

ginal input

filter can b

RE

the circuit o

on the sign

N LAB MAN

QUENC

up a frequenhz from two

EQUIPM

ency receiv

rs, incoming

receivers ex

eiver reduce

rmediate fre

uency to inte

gnal frequen

frequencie

e employed

on a breadbo

al generator

NUAL

CY MIXE

ncy converto input freq

MENTS RE

vers are the

g station fre

xhibit poor

es the incom

equency. Th

ermediate fr

ncies are fe

s and sum

d to select th

oard and sw

rs vin1 and v

ER USIN

ter circuit usquencies.

EQUIRED

fore-runner

equency is d

adjacent ch

ming high f

his is done b

requency. T

ed to a mixe

m and diffe

he desired fr

witch on vcc s

vin2

NG BJT

sing transist

D

rs of presen

directly fed

hannel rejec

frequency si

by mixing t

The principl

er it gives o

erence vers

frequency.

supply

P

tor to produ

nt super het

d to the dete

ction. To ov

ignal to mod

the incomin

e of workin

out few freq

sions of th

18

Page 18

uce an

erodyne

ector. At

vercome

derately

ng signal

ng of the

quencies

he input


ANA

Dep

CIR

DE

ALOG COMM

pt of ECE

3. The sig

4. Observe

RCUIT D

ESIGN

Use BF

Design

Tak

MUNICATION

gnal vin1 is 5

e the output

DIAGRAM

F194 transist

Let VCC =6

VCE = VRE =

of RE :

VRE =IERE

RE = VRE /

IBMIN = IC /

VB = VBE +

RB = (VCC

= (

= 115 K (

ke CC =0.1

N LAB MAN

50khz and 1

t on the CR

M

tor.

V ; IC =2

=50% of VC

IE =3/2 mA

hfe =20 micr

+ VRE =3.7V

– VB ) / IB

6 -3.7) / 20

(Use 120K

microF

NUAL

1vpp and the

RO.

mA ; hf

CC =3V

A =1.5 kohm

roA

V

std)

e signal vin2

fe =100

m

is 100khz a

P

and 1vpp 19

Page 19


ANA

Dep

RE

ALOG COMM

pt of ECE

ESULT

Designe

The inp

Output

Amplitu

MUNICATION

ed and set u

put frequenc

frequency o

ude of the o

N LAB MAN

up a frequen

cy fX =

fY =

of the mixer

output

NUAL

ncy converte

r =

=

er circuit ussing transist

P

tor.

20

Page 20


ANA

Dep

Exp

Dat

AIM T

CO

TH

are

two

IF

rece

osci

freq

IF=

IF a

tran

the

ALOG COMM

pt of ECE

p No:5

te:

M: To Design, s

OMPONETransis

IFT,

Resisto

Capacit

Signal g

DC sou

Bread b

CRO.

HEORY:

The int

two reasons

o.

amplifier is

eivers IF am

illator set i

quency fs is

fo - fs In

amplifier, th

nsformer. IF

load. IFT is

MUNICATION

set up, and p

ENTS ANDtor,

rs,

tors,

generator,

urce,

board

ermediate (

s why it sho

s an amplif

mplifiers a

is followed

s mixed wit

radio receiv

he collecto

FT provide

s tuned to 4

N LAB MAN

IF TUN

plot frequen

D EQUIP

(IF) of a rec

ould be neit

fier tuned t

are used to

d by the IF

th the local

vers the IF i

or resistance

es the tank c

455kHz.Am

NUAL

NED AM

ncy respons

PMENTS

ceiving syst

ther low nor

to intermed

amplify th

F amplifier

oscillator

is selected a

e of a conv

circuit and i

mplification p

MPLIFIE

e characteri

REUIRE

tem is usua

r high, nor

diate frequen

he signals i

in the rec

frequency f

at 445 kHz

ventional am

nductive co

peaks at int

ER

istics of an I

ED:

ally a compr

in a certain

ncy. In Tel

in IF range

ceivers. The

fo to produc

as a univer

mplifier is

oupling for t

termediate f

P

IF amplifier

romise, sin

n range betw

levision and

e. The mix

e incoming

ce the IF su

rsal standard

replaced b

the output s

frequency s

21

Page 21

r.

ce there

ween the

d Radio

xer-local

g station

uch that

d. In the

y an IF

signal to

ince the


ANA

Dep

tank

reso

indu

wh

circ

deci

amp

exam

kno

amp

the

mod

PR

1. S

2. F

3. N

freq

4. D

5. C

ALOG COMM

pt of ECE

k circuit in

onance, whe

uctive branc

here hfe is t

cuit is define

ides the ab

plifier,

IF tune

mple. Tune

own as IF tra

plifiers are u

band of fre

dulation bro

ROCEDUR

Set up the ci

Feed a sinus

Note the Am

quency vary

Draw the fre

Calculate Q

MUNICATION

IFT reso

ere, L is th

ch. Voltage

the current

ed as the ra

bility of the

ed amplifier

ed circuit tu

ansformer. I

used. In this

equencies a

oadcast rece

RE:

ircuit on bre

oidal signal

mplitude of t

ying from H

equency resp

using the fo

N LAB MAN

onates at th

he inductanc

gain of the

A

gain and R

atio of react

e amplifier

BW= fo

r is widely

uned to IF

In majority

s stage, qua

accommoda

eiver

ead board.

l of 100 mV

the output s

Hz to MHz ra

ponse chara

ormula Q= f

NUAL

hat frequen

ce is the ca

amplifier is

Av =hfeL /R

Ri is the in

tance to res

to select th

o /Q

y used in r

and induct

of commer

ality factor Q

ated is quite

V to the amp

signal and e

ange.

acteristics an

fo /BW.

ncy. The lo

apacitance a

s given by t

Ri CR

nput resista

sistance of t

he desired

receivers. S

tively coupl

rcial broad c

Q of the tun

e small bein

plifier input

enter in the t

nd mark the

ad resistanc

and R is th

the expressi

ance. The qu

the tank circ

frequency.

Super hetero

led to next

cast receive

ned circuit is

ng only 10

t.

table. Repe

e 3-dB and

P

ce equals L

he resistance

ion,

uality facto

cuit. Qualit

Bandwidth

odyne is on

stage is g

rs, two stag

s kept high

KHz in am

at for variou

centre frequ

22

Page 22

L/CR at

e of the

or of the

ty factor

h of the

ne such

enerally

ges of IF

because

mplitude

us input

uency.


ANA

Dep

CIR

DESele

DC

Des

Des

avo

Bas

Vol

Also

Vol

ALOG COMM

pt of ECE

RCUIT D

ESIGN OFection of a t

conditions

sign of RE:

sign of R1 a

id loading o

se current IB

ltage drop a

o, VR2=9IBR

ltage drop a

MUNICATION

DIAGRAM

F CC

transistor:

s: Assume V

We have R

and R2: Ass

of R1and R2

B=IC/hFE=1 m

across R2, V

R2=6.6V.Fr

across R1 is

N LAB MAN

M:

Use a high

Vcc = 12V, V

RE = VRE/IE.S

sume the cu

2 network by

mA/60=17µ

VR2=VBE+VR

om this we

VR1=VCC-V

NUAL

h frequency

Vce = 6V, V

Since IE ≈ IC

urrent throu

y the base c

µA. Since h

RE=0.6+6=6

get, R2=43k

VR2=5.4V

transistor, B

VRE = 6V and

C, RE = 6K.U

gh R1 = 101

current.

FE min of th

6.6V

k.Use 47 k

BF195 or its

d IC = 1mA

Use 5.6 K

1B and that t

he transistor

std.

P

s equivalent

through R2 =

is 60

23

Page 23

t.

= 9IB to


ANA

Dep

Also

Sel

Des

Des

resi

TAVin=

f(

ALOG COMM

pt of ECE

o VR1=101B

lection of R

sign of CC1:

sign of CE: R

stance to b

ABULAR =

(Hz)

MUNICATION

BR1=5.4V.F

RL: Take RL

: CC2 and CE

Here Rin=

We get Rin-

So, CC1 > 1

Take CC2 =

Reactance o

bypass low

XCE ≤ RE/

CE ≥ 1/2πfL

COLUM

Vo

N LAB MAN

From this we

L=1k, a nom

E: The rule

=R1 R2 hF

-1.11k.Then

/2πfL * 0.11

CC1 = 4.7µ

of emitter b

frequencies

10

L * 560=177

MN:

(volts)

NUAL

e get, R1=32

minal value.

for the desi

FE re

n XCE < 0.1

1k = 3.2µF

F

bypass capac

s to ground.

72 pF (Use 2

lo

2k.Use 33k

ign of coupl

1k at freque

citor should

2200 pF std

g f

std.

ling capacit

ency of oper

d be one-ten

d.)

20 log(Vo/

P

tor, XC1<Rin

ration 455 k

nth of emitte

/Vin) dB

24

Page 24

n/10

kHz.

er


ANA

Dep

MO

RE

VIV

Wh

Wh

Wh

Wh

Wh

List

Wh

ALOG COMM

pt of ECE

ODEL GR

ESULT: Bandwi

Q of the

VA QUES

at is meant

at are the cr

at are the ad

at is image

ich are the p

t the various

at is meant

MUNICATION

RAPH:

idth of the c

e circuit =

STIONS:

by intermed

riterion for

dvantages o

signal frequ

parameters

s application

by Q-factor

N LAB MAN

circuit =….

…………..

diate freque

choosing in

of using BF

uency?

affecting th

ns of IF am

r?

NUAL

..…..Hz

ency?

ntermediate

195 tansisto

he working

mplifier?

frequency?

or in the cir

of an ampli

?

rcuit?

ifier?

P

25

Page 25


ANA

Dep

Exp

Dat

AIM

rang

CO

TH

synt

dete

feed

diff

volt

freq

will

equ

freq

inpu

is re

freq

limi

ALOG COMM

pt of ECE

p No:6

te:

M: To desi

ge and lock

OMPONEPLL Ch

Resisto

Capacit

Dc Pow

Signal G

Breadbo

HEORY: Monoli

thesizers, m

ector, an L

dback frequ

ference betw

tage control

quency and

When t

l be in free

al to input

quency incre

ut frequency

educed, VC

quency is fu

it of fL1. If i

MUNICATION

P

ign a PLL range. Plot

ENTS ANDhip - NE 56

rs,

tors,

wer Supply,

Generator,

oard.

thic PLL is

motor speed

PF and a V

uency. Outp

ween freque

ls VCO fre

automatical

the input fre

running sta

frequency.

eases; VCO

y further in

CO frequen

urther reduc

input freque

N LAB MAN

PHASE

circuit for t the frequen

D EQUIP5

a highly ve

control, FS

VCO. Phas

put of pha

encies. Low

equency. VC

lly gets itse

equency is l

ate. When in

. In other w

O frequency

ncreases, VC

ncy become

ced VCO fr

ency is again

NUAL

LOCKE

free runninncy graph.

PMENTS

ersatile devi

SK demodul

se detector

ase detector

w pass filter

CO frequen

lf equal to t

less than fL

nput frequen

words, VCO

y follows the

CO retains

s equal to

requency fo

n reduced, V

ED LOO

ng frequency

REQUIR

ice used for

lators etc. P

compares

r is a dc v

r removes h

ncy is fed b

the input fre

L, PLL is ne

ncy reaches

O captures

e input freq

the free run

input frequ

ollows the in

VCO goes b

OPS

y of 2.5KH

RED:

r FM demod

PLL mainly

the input f

voltage prop

high freque

back and co

equency.

either in loc

s fC1, VCO f

input frequ

quency up to

nning state.

uency only

nput freque

back to the

P

Hz.Find the

dulation, fre

consists of

frequency w

portional to

ency noise.

ompared wit

ck nor in cap

frequency b

uency. If th

o the limit o

If input fre

at fC2. If th

ency only u

free running

26

Page 26

capture

equency

f a phase

with the

o phase

The dc

th input

pture. It

becomes

he input

of fL2. If

equency

he input

up to the

g state.


ANA

Dep

lock

whi

PR

BL

ALOG COMM

pt of ECE

Lock ra

k with inpu

ich PLL is a

ROCEDUR

1. Set up t

2. Note do

3. Feed

frequen

fC2 and

4. Calcula

LOCK DIA

MUNICATION

ange fL2-fL1

ut frequency

able to captu

RE:

the circuit a

own the free

an input sig

ncy terminal

fL1.

ate capture r

AGRAM

N LAB MAN

can be def

y. Capture r

ure the inpu

after verifyin

e running fr

gnal either

ls and vary

range and lo

NUAL

fined as the

range fC2-fC

ut frequency

ng the cond

requency fO

sine wave

y its frequen

ock range.

range of fr

C1 is defined

y. fL will be

dition of com

without any

or square w

ncy from 10

requency in

d as the ran

greater tha

mponents.

y input sign

wave to an

00Hz.to 4K

P

n which PLL

nge of frequ

an fC.

nal.

ny one of th

KHz and not

27

Page 27

L keeps

uency in

he input

te down


ANA

Dep

CIR

DE

ALOG COMM

pt of ECE

RCUIT D

ESIGN:

Let V

Let th

Take

Then

The v

Take

The t

fL = +

fc = +

MUNICATION

DIAGRAM

V+= +10V an

he free run

e C1= 0.01µ

n R1 = 12K

value of R1

e C3 = 0.01

theoretical v+/-8fo/V

+/-(f1/2)/(2*п

N LAB MAN

M

nd V- = -10V

nning freque

µF

satisfies th

µF and C2=

values of fL

*3.6*103*C

NUAL

V

ency, f0 =1.2

he required c

= 10µF

L and fc is gi

C2)1/2

2/(4R1*C1)

condition 2K

iven by

) = 2.5KHz

K<R1<20K

P

K

28

Page 28


ANA

Dep

EX

RE

calc

ALOG COMM

pt of ECE

XPECTED

ESULT. Designe

culated the l

MUNICATION

D WAVEF

ed and set

lock range a

Lo

Captur

N LAB MAN

FORM

up a PLL

and capture

ock range fL

re range fC

NUAL

circuit for

range.

L =

=

free runni

ng frequen

P

cy of 2.5K

29

Page 29

KHz and


ANA

Dep

Exp

Dat

AIM

mod

CO

TH

carr

ban

stan

dete

whi

hosp

syst

whi

inpu

One

VCO

ALOG COMM

pt of ECE

p No:7

te:

M To setu

dulation ind

OMPONELM 565

Resisto

Capacio

Power s

Signal g

Bread b

HEORY Frequen

rier. In an F

d) signal w

ndard techni

ectors, whe

ich are the d

Frequen

pital comm

tems, and ra

PLL sta

ich function

ut and outp

e of of its m

O is a meas

MUNICATION

up and study

dex from the

ENTS REQ5 (phase loc

rs- 3.3 KΩ,

ors-0.01µF,

supplies,

generator,

board etc

ncy modula

FM signal, t

while its am

ique for hig

en properly

dominant pa

ncy modula

munications,

adio amateu

ands for ph

ning is base

ut controlle

many appli

sure of the in

N LAB MAN

FM M

y an FM gen

e output wa

QUIREDcked loop)

, 10 KΩ,

0.01µF,

ation is an

the frequen

mplitude rem

gh-fidelity T

designed,

art of electri

ation is us

emergency

ur bands abo

hase locked

ed on phase

ed oscillator

ications and

nput freque

NUAL

MODUL

nerator usin

aveform.

WITH D

important

cy of the si

mains the sa

The main re

are not se

ical

ed in com

y channels,

ove 30 MHz

loop and is

sensitive d

r. It contain

d features i

ency, with o

LATOR

ng 565 PLL

DETAILE

method of

ignal is cha

ame. Frequ

eason for the

ensitive to

mmercial rad

TV sound,

z.

s basically

detection of

ns a phase d

is tone-deco

obvious appl

IC and to c

ED SPECI

impressing

anged by the

uency modu

e improved

random am

dio broadca

, wireless (

a closed lo

f phase diffe

detector, am

oding.the c

lications.

P

alculate

IFICATIO

g informatio

e modulatio

ulation (FM

d fidelity is t

mplitude va

asts in pol

(cellular) te

oop control

erence betw

mplifier, an

ontrol inpu

30

Page 30

ON

on on a

on (base

M) is the

that FM

ariations

lice and

lephone

system,

ween the

d VCO,

ut to the


ANA

Dep

high

and

is se

with

over

betw

obta

Pha

freq

loop

A l

loop

the

lock

inpu

ensu

tran

para

imp

WO

FM

grou

and

outp

dete

ALOG COMM

pt of ECE

The LM

hly linear v

a double b

et with an e

h the same

r a wide ra

ween the V

ain frequenc

A Phas

ase-lock. Th

quency is ca

p acquires p

ow-pass fil

p. If the dif

resultant s

ked, the fil

ut frequenc

uring a rap

nsient. How

ameters of

possible for

ORKINGOnly th

output. Ini

unded. The

also input t

The mo

put. This ou

ector are gro

MUNICATION

M565 is a

voltage con

alanced pha

external res

capacitor. T

ange with

VCO and the

cy multiplic

se-Locked

he range ov

alled the loc

phase-lock i

lter is used

fference be

signal is ou

lter only li

cy. In addi

pid recaptur

wever, a de

that filter r

r the phase-

G OF THEhe VCO mo

itially the V

message si

to the ampli

odulated ou

utput will be

ounded and

N LAB MAN

general pu

trolled osci

ase detector

istor and ca

The charact

an externa

e phase det

cation.

Loop has

ver which

ck range. O

is the captur

d to contro

etween the

ut of the ca

mits the sp

ition, the lo

re of the sig

esign of a

restrict the l

-locked loop

E CIRCUIodule of the

VCO oscilla

ignal is giv

ifier also.

utput is obt

e the FM ou

pin no: 5 w

NUAL

urpose Phas

illator (VCO

r with good

apacitor, an

teristics of t

l resistor a

tector for in

basically t

the loop sy

On the other

re range, an

l the dynam

input and

apture rang

peed of the

oop filter p

gnal if the

loop filter

loop's captu

p to lock w

IT: e PLL is us

ates at its f

ven to pin n

tained at p

utput. Pin n

which conne

se-Locked L

O) for low

carrier sup

nd a tuning

the closed l

and capacito

nsertion of

three states

ystem will

r hand, the

nd is never g

mic charac

VCO frequ

ge of the lo

e loop's ab

provides a

system is th

r represent

ure range a

without it.

sed. And th

free running

no.7 of the I

pin no.4 of

no: 2 and 3 a

ects VCO to

Loop IC co

distortion

ppression. T

range of 10

oop system

or. The loo

a digital fr

s- Free-runn

follow cha

frequency

greater than

cteristics of

uencies is s

oop. Once t

bility to tra

sort of sh

hrown out

ts a compr

and speed, i

he VCO out

g frequency

IC which is

f the PLL w

are the two

o phase

P

ontaining a

FM demod

The VCO fre

0:1 can be o

m-- may be a

op may be

requency div

ning, Captu

anges in th

range in wh

n the lock r

f the phase

significantly

the loop is

ck changes

hort-term m

of lock by

romise in t

it would alm

tput is taken

y when pin

s input to th

which is th

inputs to th

31

Page 31

a stable,

dulation,

equency

obtained

adjusted

broken

vider to

ure and

he input

hich the

range.

e-locked

y large,

s phase-

s in the

memory,

a noise

that the

most be

n as the

no:7 is

he VCO

he VCO

he phase


ANA

Dep

the

volt

PR

ALOG COMM

pt of ECE

compar

VCO.VCO

tage acts s th

ROCEDUR1. Set up t

2. Withou

frequen

3. Feed th

Increase

4. Observe

frequen

index.

MUNICATION

rator is unco

O frequency

he control v

RE the circuit o

ut feeding th

ncy of the ou

he modulat

es when con

e the FM ou

ncy of the w

N LAB MAN

onnected al

y should com

voltage whi

on the bread

he modulati

utput square

ting signal

ntrol voltag

ut put on th

waveform an

NUAL

lso. The AF

me in Lock

ch modulat

d board.

ng signal, o

e wave.

of 2V.It c

ge Vc decrea

he screen an

nd calculate

F input to p

k with the i

es the volta

observe and

can be see

ases and vis

d note down

e the freque

pin no 7 var

input freque

age controlle

d note down

en that the

se versa.

n the maxim

ency deviati

P

ry the frequ

ency. Usua

ed oscillator

n the amplit

output fre

mum and m

ion and mod

32

Page 32

uency of

lly a dc

r.

tude and

equency

minimum

dulation


ANA

Dep

CIR

DE

equ

Sele

Sele

Let

From

form

ALOG COMM

pt of ECE

RCUIT D

ESIGN Let the

ation

ecting the v

V+= 10v

ƒ0= 1.2 /

ect the free

the free run

m the form

ms a part of

MUNICATION

DAIGRAM

free runnin

oltages as

v and V-= -

/ 4 R1C1

running fre

nning frequ

mula it is cle

f the low pas

N LAB MAN

M:

ng frequenc

10v for the

quency dete

uency be 2.5

ear that the

ss filter is se

NUAL

cy of the p

chip.

ermined acc

5 kHz. And

resistor va

elected to b

hase locked

cording to c

d select the

alue will be

be 0.01µF

d loop is de

capacitor an

capacitor v

e12K. The c

P

etermined b

nd resistor v

value to be

capacitor C

33

Page 33

by the

values.

0.01µF.

C2 which


ANA

Dep

WA

RE

obse

usin

for v

ALOG COMM

pt of ECE

AVEFOR

ESULT: Frequen

erved on a C

ng the form

various freq

MUNICATION

RMS:

ncy modula

CRO. The m

mula: ß= fre

quencies is

N LAB MAN

ation has b

modulation

quency dev

carried out.

NUAL

been done u

index has b

viation /mes

using 565

been calcula

ssage signa

IC and the

ated from th

al frequency

P

e output wa

he output wa

y and measu

34

Page 34

aveform

aveform

urement


ANA

Dep

VIV

ALOG COMM

pt of ECE

VA VOIC1. What y

2. What ar

3. What ar

4. What is

5. What is

6. How PL

7. Explain

8. Give an

9. What ar

10. What y

11. Give th

12. Explain

13. What ar

14. How PL

15. Explain

MUNICATION

CE ou mean by

re the differ

re the advan

s ment by lo

s ment by ca

LL can be u

n a 565 IC?

n example fo

re the differ

ou mean by

he general ex

n draw back

re the limita

LL works as

n different m

N LAB MAN

y frequency

rent types o

ntages of fre

ock range?

apture range

used for FM

for VCO?

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FM?

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35

Page 35


ANA

Dep

Exp

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AIM To d CO

TH

info

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dep

the

Slop

Fost

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tend

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p No:8

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original mo

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36

Page 36

presents

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NBFM)

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k signal

k signal


ANA

Dep

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37

Page 37

quantity

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is


ANA

Dep

CIR

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38

Page 38


ANA

Dep

EX

RE

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39

Page 39

l


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40

Page 40


ANA

Dep

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pt of ECE

p No:9

te:

AIM: To design a

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41

Page 41

RO

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42

Page 42

arrier is

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43

Page 43


ANA

Dep

RE The

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ESULT:

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44

Page 44


ANA

Dep

Exp

Dat

AIM

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45

Page 45

using an

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46

Page 46

mplitude

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47

Page 47


ANA

Dep

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EX

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ESIGN better integ RC > 1the clock fr So T = Take C

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48

Page 48


ANA

Dep

Exp

Dat

AI CO

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mod

wid

vari

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49

Page 49

e length

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timer is

ble time


ANA

Dep

volt

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state

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50

Page 50

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RCUIT D

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51

Page 51


ANA

Dep

EX

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VIVWh

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met

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52

Page 52

ation


ANA

Dep

Exp

Dat

AIM

CO

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refe

diff

mon

PW

the

PR

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pt of ECE

p No:12

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To desi

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erence posit

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53

Page 53

.

from a

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Dep

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MUNICATION

the monosta

CRO observ

ate the pulse

ate the pulse

ate the pulse

e signal grap

DIAGRAM

ble multivi

V, ms and td = 0quqtion 69 (Ra + Rb69 Rb*C µF b = 6.8K

N LAB MAN

able circuit

e the PPM o

e width mod

e position m

e width of P

ph by using

M:

ibrator:

0.5ms

b) C

NUAL

and feed th

output.

dulated outp

modulated ou

PPM wave.

the values.

e PWM out

put voltage.

utput voltag

tput to it .

ge.

P

54

Page 54


ANA

Dep

Des Tak

We

EX

RE

PPM

ALOG COMM

pt of ECE

sign of mon

ke the pulse T = 1m

have the eq T = 1.1 Take R

XPECTED

ESULT:

M circuit usPulse wPulse pPulse w

MUNICATION

nostable mu

duration ms

quation,

RC = 10K then

D WAVEF

ing NE555 width modulosition mod

width of PPM

N LAB MAN

ultivibrator

n C = 0.1µF

FORM:

is desighnelated O/P vodulated O/PM wave =

NUAL

r:

F

ed and set upoltage = voltage =

p and verifiied.

P

55

Page 55


ANA

Dep

Exp

Dat

P

AIM

CO

TH puls

wid

is v

and

the

cod

and

ALOG COMM

pt of ECE

p No:13

te:

PULSE W

M

To desi

OMPONE IC 741C

Resisto

Capacit

Potentio

Signal G

DC Sou

Bread b

CRO.

HEORY

PWM i

se length mo

dth of pulses

aried with r

the time o

transmissio

e modulatio

PWM c

reference r

MUNICATION

WIDTHMO

ign and set u

ENTS AND

C,

rs,

tors,

ometers,

Generators,

urce,

board

is analog p

odulation. I

s is varied a

respect to a

f tracking i

on of PWM

on.

can be gene

ramp wavef

N LAB MAN

MODUDULAT

up a pulse w

D EQUIP

ulse modul

It utilizes th

according to

reference p

is determine

is more as

erated using

forms are f

NUAL

ULATIONTION US

width and pu

PMENTS

lation techn

he advantage

o the amplit

position. Th

ed by the m

in the case

g a compara

fed. A PPM

N AND PSING OP

ulse positio

REQUIR

nique. It is

es of consta

tude of AF

he rising edg

modulating s

of PAM tr

ator to whic

M waveform

PULSE P-AMP

n modulatio

RED

also called

ant amplitud

signal. The

ge of the pu

signal. The

ransmission

ch the signa

m can be der

P

POSITI

on using op

d pulse dura

de pulses. In

e width of th

ulse is the re

energy nee

compared

al to be mo

rived from

56

Page 56

ION

-amp.

ation or

n PWM

he pulse

eference

eded for

to pulse

odulated

a PWM


ANA

Dep

wav

PPM

PR

CIR

DELet

Let

For

Tak

ALOG COMM

pt of ECE

veform. The

M, location

ROCEDUR

1. Check

2. Set up

3. Give

4. Obse

RCUIT D

ESIGN T = 1ms

β= (R1/R2)

saw tooth g

vp-p of s

ke vp-p = 15v

i.e, R1 =

MUNICATION

e relationsh

of leading e

RE

k the condit

p the circuit

the modula

erve the wav

DIAGRAM

) = 1/2 ; C

generator ,

sawtooth wa

v, vsat = ±15

= (15/5)*(10

N LAB MAN

hip between

edge is varie

tions of the

t on bread b

ting signal a

veform on C

M

C=0.1µF

aveform = (

5v, R2 =10 k

0 kohm/2) =

NUAL

the two is

ed in PPM w

op-amp.

board.

after the gen

CRO.

(2R1/R2).vsa

kohm

= 5kohm,. U

that while

with consta

neration of

at

Use 5.6 koh

the position

ant width.

sawtooth.

m std

P

n of pulse v

57

Page 57

varies in


ANA

Dep

Freq

Tak

Tak

For

The

EX

RE

ALOG COMM

pt of ECE

quency,

ke f=5khz,

ke R4 as 22

differentiat

RC<<0

RC<<4

en RC=10

XPECTED

ESULT

Designe

MUNICATION

f=(R2/4*R1

,C=0.01µf,

2 kohm pot

tor:

.0016T ; H

0*10^-8 s

*10^-8 s<<

D WAVEF

ed and set u

N LAB MAN

1.R3.C)

R1=5kohm,

Here T =0.2

Take C=0

< 40*10^-8 s

FORM:

up pulse wid

NUAL

, R2= 10 ko

25 ms

.001µf and

s

dth and puls

hm i.e, R3=

R=100 ohm

se position m

=10kohm

m

modulator u

P

using op-am

58

Page 58

mp.


ANA

Dep

EX

ALOG COMM

pt of ECE

XAMINAT

1. Design

to m =

2. Design

3. Obtain

6sin2Π

4. Generat

modula

it.

5. Design

6. Implem

obtain t

7. Design

bandwi

8. Produce

9. Genera

and dem

10. Obtain

MUNICATION

TION QU

and set up

1, m <1 and

and setup a

the modul

15000t. Als

te a modul

ating signal.

and setup a

ment and se

the demodu

and setup

dth to great

e the signal

ate f1 and f2

modulate it.

the signal

N LAB MAN

UESTION

a circuit for

d m>1.

a product m

ated o/p co

so demodula

ated signal

. Choose ca

a narrowban

etup to tran

ulated one.

a BPF fo

ter than 15K

l using an a

2 and perfo

NUAL

NS:

r AM gener

modulator cir

orrespond t

ate it.

having ba

arrier as 600

nd pass filte

nsmit an au

or a bandw

KHz.

analog switc

orm convolu

ration obtain

rcuit and tun

to audio sig

andwidth 2*

0KHz and A

er for a reson

udio signal

width of 10

ch.

ution so as

n the wavef

ne it to 455K

gnal 5sin2Π

*highest fre

AF as 1KHz

nance frequ

which is F

0KHz and l

to get the g

P

form corresp

KHz

Π1000t and

equency con

z. Also dem

uency of 455

FM modula

later increa

given wave

59

Page 59

ponding

d carrier

ntent of

modulate

5KHz.

ated and

ases the

eform


ANA

Dep

ALOG COMM

pt of ECE

11. Generat

12. Design

carrier p

13. Experim

detector

14. Experim

detector

15. Design

16. Detect t

17. Design

18. Design

MUNICATION

te an AM si

and set up

power. Carr

mentally pr

r varies with

mentally fin

r varies with

and setup a

the AM mo

an AM de-

a circuit to

N LAB MAN

ignal with 3

an AM circ

rier frequen

rove that th

h RC time c

nd out that th

h time cons

an AM detec

odulated sign

modulator t

display onl

NUAL

30% modula

cuit so that t

ncy = 100KH

he quality

constant.

he quality o

stant RC.

ctor circuit.

nal and amp

to detect on

ly the carrie

ation

the transmit

Hz

of a detec

of the detect

.

plify the out

nly the negat

er signal.

tted power i

cted signal

ted signal fr

tput.

tive envelop

P

is 104.5% o

from an

rom an enve

pe.

60

Page 60

f the

envelop

elope


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ANALOG COMMUNICATION LAB MANUAL - Ammini … 408(P)_ Analog... · Department of Electronics and Communication Engineering EC 09 408(P) ANALOG COMMUNICATION LAB MANUAL DEPT. OF ELECTRONICS