advanced communication laboratory final manual

8/13/2019 Advanced Communication Laboratory Final Manual

1/62


2/62

roughly from /cm to cm (1-1/ $! and the waves having wavelengths

less than cm corresponds to higher frequencies (21/ $! are called

millimeter (mm waves.

Micro a!e Fre%#e$cie&:

3elationship between the frequency (f and the wavelength (4 of an

M wave is

where c 5 velocity of electromagnetic radiation, usually called the speed of

light.

IEEE Micro a!e Fre%#e$c' (a$ :

De&i*$atio$Fre%#e$c'

ra$*e +,H-)$% /.//1 5 /./1'$% /./1 5 /.1#$% /.1 5

5 6and - 7S 5 6and 7 - 89 5 6and 8 - ; 5 6and - 7


3/62

i"e any other energy, microwave energy has a heating effect, it is

used in microwave oven for home coo"ing, drying machine, drying in"s, and

in food processing industries.

Microwaves are capable of energetically interacting with matter and

so used in microwave spectroscopy for structural analysis. >part from

scientific research the absorption of microwave by molecular resonance is

well suited for various industrial measurements li"e control of pollution by

chec"ing the concentration of different gases from an e+haust chimney.

Micro a!e Co"po$e$t&:

There are several microwave components are discussed below.

2YSTRON MOUNT:

Model 7/? n octal base with cable

is provided for


4/62

Model 0/7 and 0/77 are T and C types of three port circulators

respectively. These are precisely machined and assembled to get the

desired specifications. 9irculators are matched three port devices and these

are meant for allowing Microwave energy to flow in cloc"wise direction with

negligible loss but almost no transmission in the anti-cloc"wise direction.

Speci/icatio$&:

Model Ao. : ; - 0/7

%requency 3ange ( $! : .0 - /.0 or /.7 - 7.7

Min. *solation (d6 : 7/

Ma+. *nsertion oss (d6 : /.8

Ma+. 'SB3 : .7/

S2IDE SCREW TUNERS:

Model 8/8 slide screw tuners are used for matching purposes by

changing the penetration and position of a screw in the slot provided in the

centre of the wave guide.

This consists of a section of waveguide flanged on both ends and a

thin slot is provided in the broad wall of the Bave guide. > carriage carrying

the screw is provided over the slot. > 'SB3 upto 7/ can be tuned to a value

less than ./7 at certain frequency.

4


5/62

Speci/icatio$&:

Model Ao. : ; 5 8/8

%requency 3ange ( $! : .7 - 7.8

B Type (B3- : @/

%lange type (# : 1@

MU2TIHO2E DIRECTIONA2 COU32ERS:

Model 0/// series Multihole directional couplers are useful for

sampling a part of microwave energy for monitoring purposes and for

measuring reflections and impedance.

This consists of a section of Bave guide with addition of a second

parallel section of waveguide thus ma"ing it a four port networ". $owever

the fourth port is terminated with a matched load. These two parallelsections are coupled to each other through many holes, almost to give

uniform couplingD minimum frequency sensitivity and high directivity. These

are available in 1,0, /,7/ and 8/d6 coupling.

Speci/icatio$&:

Model Ao. : ; - 0//1

%requency 3ange ( $! : .7 - 7.8

9oupling (d6 : 1, /,7/,8/

Eirectivity (d6 : 1?

5


6/62

Bave guide type (B3- : @/

%lange type (# : 1@

E 32ANE TEE:

Model 1/0 - plane tee are series type T - Function and consists of

three section of waveguide Foined together in order to divide or compare

power levels. The signal entering the first port of this T - Function will be

equally dividing at second and third ports of the same magnitude but in opp.

phase

Speci/icatio$&:

Model Ao. : ; - 1/0

%requency 3ange ( $! : .7 - 7.8

B Type (B3- : @/

%lange Type (# : 1@

H 4 32ANT TEE:

Model 1/0? $ - Glane Tee are shunt type T - Function for use in

conFunction with 'SB3 meters, frequency - meters and other detector

devices. i"e in -plane tee, the signal fed through first port of $ - plane Tee

will be equally divided in magnitude at second and third ports but in same

phase.

6


7/62

Speci/icatio$&:

Model Ao. : ; - 1/0?

%requency 3ange ( $! : .7 - 7.8

B Type (B3- : @/%lange Type (# - : 1@

MA,IC TEE:

Model 1/8? - $ Tee consists of a section of wave guide in both series

and shunt waveguide arms, mounted at the e+act midpoint of main arm.

6oth ends of the section of waveguide and both arms are flanged on their

ends. These Tees are employed in balanced mi+ers, >%9 circuits and

impedance measurement circuits etc. This becomes a four terminal devicewhere one terminal is isolated from the input terminal.

Speci/icatio$&:

Model Ao. : ; - 1/8?

7


8/62

%requency 3ange ( $! : .7 - 7.8

B Type (B3- : @/

%lange Type (#3- : 1@

3YRAMIDA2 WAVE,UIDE HORN ANTENNA:

Model ?/8 pyramidal Bave guide $orn antenna consists of

waveguide Foined to pyramidal section fabricated from brass sheet. The

pyramidal section shapes the energy to concentrate in a specified beam.

Baveguide horns are used as feed horns as radiators for reflectors and

lenses and as a pic"up antenna for receiving microwave power.

Speci/icatio$&:

Model Ao. : ; - ?/8

%requency 3ange ( $! : .7 - 7.8

Ma+ 'SB3 : .7/B Type (B3- : @/

%lange Type (# - : 1@

,UNN OSCI22ATORS:

Model 7 ? unn )scillators are solid state microwave energy

generators. This consists of waveguide cavity flanged on one end and

micrometer driven plunger fitted on the other end. > unn-diode is mounted

inside the Bave guide with 6A9 (% connector for E9 bias. ach unn

oscillator is supplied with calibration certificate giving frequency vs

micrometer reading.

8


9/62

Speci/icatio$&:

Model Ao. : ; 5 7 ?7

%req : .7 - 7.8 $!,

Min output power : / MB

B Type (B3- : @/

%lange Type (# - : 1@

,UNN 3OWER SU332Y:

Model ;- / unn Gower supply comprises of an regulated E9 power

supply and a square wave generator, designed to operate unn-)scillator

model 7 ? or 7 ?7, and pin modulators model 8? respectively.

The E9 voltage is variable from / - /'. The front panel meter

monitors the unn voltage and the current drawn by the unn diode. The

square wave of generator is variable from / - /'. in amplitude and @// -// $! in frequency.

The power supply has been so designed to protect unn diode from

reverse voltage application over transient and low frequency oscillations by

the negative resistance of the unn-diode.

9


10/62

Speci/icatio$&:

>mplifier Type : $igh gain tuned at one frequency

%requency : /// $! H 7I

Sensitivity : /. microvolt at 7// for full scale

6and width : 7? - 1/ cps

3ange : =/d6 min in / d6 steps

Scale selector : Aormal +pand

ain control : J9oarseK L J%ineK

Mains power : 71/', ?/$!

ISO2ATORS :

The three port circulators Model 0/7 may be converted into isolators

by terminating one of its port into matched load. these will wor" over the

frequency range of circulators. These are well matched devices offering low

forward insertion loss and high reverse isolation.

Speci/icatio$&:

Model Ao. : ; - 0/77

%requency 3ange ( $! : .0 - /.0 or /.7 - 7.7

Min *solation (d6 : 7/

Ma+ *nsertion oss (d6 : /.8Ma+ 'SB3 : .7/

RESU2T:

10


11/62

Thus all the microwave communication and their components were

studied in detail.

Expt. No.:

15) STUDY OF MICROWAVE COM3ONENTS USIN, MAT2A(Date:

AIM:

To study and simulated the S-matri+ for various types of following

microwave components using M>T >6.

a *solator

b Eirectional 9ouplerc Magic Tee

SOFTWARE USED:

M>T >6

FORMU2A USED:

11


12/62

a *solators:

b Eirectional 9oupler:

c Magic Tee:

where

G 5 *nput power at port

G7 5 )utput power at port 7

G1 5 9oupled power at port 1

G8 5 *solated Gower at port 8

THEORY:

Microwave techniques have been increasingly adopted in such diverseapplications as radio astronomy, long distance communications, space

navigation, radar systems, medical equipment and missile electronic

systems.

Nee o/ S para"eter&:

12


13/62

*f the frequencies are in the microwave range, however, the $,C and

parameters cannot be measured for the following reasons:

a quipment is not readily available to measure total voltage and total

current at the ports of the networ".

b Short and open circuits are difficult to achieve over a broadband of

frequencies.

c >ctive devices, such as power transistors and tunnel diodes,

frequently will not have stability for short or open circuit.

I&o0ator&:

>n isolator is a non-reciprocal transmission device that is used to

isolate one component from reflections of other components in the

transmission line. >n ideal isolator can be constructed in many ways. They

can be made by terminating port 1 and port 8 of a four port circulator with

matched loads. *t may be inserting a ferrite rod along the a+is of a

rectangular waveguide. The S matri+ is given by:

Directio$a0 Co#p0er&:

*t is a four port waveguide Function is shown in figure. *t consists of a

primary waveguide 5 7 and secondary waveguide 1 5 8. Bhen all ports are

terminated in their characteristic impedances, there is free transmission of

power between port and 1 or port 7 and 8 because no coupling e+ists

between these two pairs os ports. The degree of coupling between port

and 8 and between port 7 and 1 depends on the structure of the coupler.

The S matri+ is given by

13


14/62


15/62

CHARACTERISATION OF MICROWAVE COM3ONENTS3RO,RAM CODE:clcDclear allDdisp(O*S) >T)3O D

15


16/62

disp(O*AG#T: O DGsNinput(O nter *nput Gower: O DGs Ninput(O nter )utput Gower: O Dp NGs -GsDan Np &7/Dsp N /P(an DGs7Ninput(O nter )utput Gower: O D

p7NGs7-GsDan7Np7&7/Dsp7N /P(an7 Dsm NQ/ sp Dsp7 /RDiserloss NGs-Gs Disoloss NGs-Gs7Ddisp(O)#TG#T: O Ddisp(O*nsertion oss (d6 : O Ddisp(iserloss Ddisp(O*solation oss (d6 : O Ddisp(isoloss Ddisp(OS-matri+ of *solator: O Ddisp(sm Ddisp(OE*3 9T*)A> 9)#G 3O Ddisp(O*AG#T: O DGs1Ninput(O nter )utput Gower: O Dp1NGs1-GsDan1Np1&7/Dsp1N /P(an1 DGs8Ninput(O nter )utput Gower: O Dp8NGs8-GsDan8Np8&7/Dsp8N /P(an8 DGs?Ninput(O nter )utput Gower: O Dp?NGs?-GsDan?Np?&7/Dsp?N /P(an? DGs0Ninput(O nter )utput Gower: O Dp0NGs0-GsD

an0Np0&7/Dsp0N /P(an0 DGs=Ninput(O nter )utput Gower: O Dp=NGs=-GsDan=Np=&7/Dsp=N /P(an= DGs Ninput(O nter )utput Gower: O Dp NGs -GsDan Np &7/Dsp N /P(an DGs@Ninput(O nter )utput Gower: O Dp@NGs@-GsDan@Np@&7/Dsp@N /P(an@ DGs /Ninput(O nter )utput Gower: O Dp /NGs /-GsDan /Np /&7/Dsp /N /P(an / DGs Ninput(O nter )utput Gower: O Dp NGs -GsDan Np &7/Dsp N /P(an DGs 7Ninput(O nter )utput Gower: O Dp 7NGs 7-GsDan 7Np 7&7/D

16


17/62

sp 7N /P(an 7 DGs 1Ninput(O nter )utput Gower: O Dp 1NGs 1-GsDan 1Np 1&7/Dsp 1N /P(an 1 DGs 8Ninput(O nter )utput Gower: O Dp 8NGs 8-GsD

an 8Np 8&7/Dsp 8N /P(an 8 Dsm7NQ/ sp1 sp8 sp?Dsp0 / sp= sp Dsp@ sp / / sp Dsp 7 sp 1 sp 8 /RDcouplefact NGs-Gs8Ddirect NGs8-Gs?Diserloss7NGs-Gs1Disoloss7NGs-Gs?Ddisp(O)#TG#T: O Ddisp(O9oupling %actor (d6 : O Ddisp(couplefact Ddisp(OEirectivity (d6 : O Ddisp(direct Ddisp(O*nsertion oss (d6 : O Ddisp(iserloss7 Ddisp(O*solation oss (d6 : O Ddisp(isoloss7 Ddisp(OS-matri+ of Eirectional 9oupler: O Ddisp(sm7 Ddisp(OM> *9 T O Ddisp(O*AG#T: O DGs ?Ninput(O nter )utput Gower: O Dp ?NGs ?-GsDan ?Np ?&7/Dsp ?N /P(an ? DGs 0Ninput(O nter )utput Gower: O Dp 0NGs 0-GsDan 0Np 0&7/Dsp 0N /P(an 0 DGs =Ninput(O nter )utput Gower: O D

p =NGs =-GsDan =Np =&7/Dsp =N /P(an = DGs Ninput(O nter )utput Gower: O Dp NGs -GsDan Np &7/Dsp N /P(an DGs @Ninput(O nter )utput Gower: O Dp @NGs @-GsDan @Np @&7/Dsp @N /P(an @ DGs7/Ninput(O nter )utput Gower: O Dp7/NGs7/-GsDan7/Np7/&7/Dsp7/N /P(an7/ DGs7 Ninput(O nter )utput Gower: O Dp7 NGs7 -GsDan7 Np7 &7/Dsp7 N /P(an7 DGs77Ninput(O nter )utput Gower: O Dp77NGs77-GsDan77Np77&7/Dsp77N /P(an77 DGs71Ninput(O nter )utput Gower: O Dp71NGs71-GsD

17


18/62

an71Np71&7/Dsp71N /P(an71 DGs78Ninput(O nter )utput Gower: O Dp78NGs78-GsDan78Np78&7/Dsp78N /P(an78 DGs7?Ninput(O nter )utput Gower: O D

p7?NGs7?-GsDan7?Np7?&7/Dsp7?N /P(an7? DGs70Ninput(O nter )utput Gower: O Dp70NGs70-GsDan70Np70&7/Dsp70N /P(an70 Dsm1NQ/ sp ? sp 0 sp =Dsp / sp @ sp7/Dsp7 sp77 / sp71Dsp78 sp7? sp70 /RDcouplefact7NGs-Gs 0Ddirect7NGs 0-Gs77Diserloss1NGs-Gs ?Disoloss1NGs-Gs =Ddisp(O)#TG#T: O Ddisp(O9oupling %actor (d6 : O Ddisp(couplefact7 Ddisp(OEirectivity (d6 : O Ddisp(direct7 Ddisp(O*nsertion oss (d6 : O Ddisp(iserloss1 Ddisp(O*solation oss (d6 : O Ddisp(isoloss1 Ddisp(OS-matri+ of Eirectional 9oupler: O Ddisp(sm1 D

SAM32E IN3UT AND OUT3UT:

ISO2ATORIN3UT:

nter *nput Gower Gin(d6 : - 7

G)3T nter )utput Gower G7(d6 : - 7G)3T 7

nter )utput Gower G (d6 : -7 .

OUT3UT:*nsertion oss (d6 :

/*solation oss (d6 :

@. ///S-matri+ of *solator:

/ .//// /.1710 /

DIRECTIONA2 COU32ERIN3UT:G)3T

nter )utput Gower G7(d6 : - 7.nter )utput Gower G1 (d6 : -70.nter )utput Gower G8 (d6 : -?0

G)3T 7nter )utput Gower G (d6 : - 7.nter )utput Gower G1(d6 : -?8.?nter )utput Gower G8(d6 : -70.7

G)3T 1

18


19/62

nter )utput Gower G (d6 : -70.7nter )utput Gower G7(d6 : -?8.=nter )utput Gower G8(d6 : - 7.

G)3T 8nter )utput Gower G (d6 : -?1.?nter )utput Gower G7(d6 : -70.nter )utput Gower G1(d6 : - 7.@

OUT3UT:9oupling %actor (d6 :

8. ///Eirectivity (d6 :

[email protected]///*nsertion oss (d6 :

/. ///*solation oss (d6 :

88S-matri+ of Eirectional 9oupler:

/ /.@ 7/ /. 7/ /.//01 /.@ 7/ / /.//=? /. @?/ /. @?/ /.//=1 / /.@ 7/ /.// 8 /. @=7 /.@/ 0 /

MA,IC TEEIN3UT:G)3T

nter )utput Gower G7(d6 : - 1.nter )utput Gower G1(d6 : - 1.nter )utput Gower G8(d6 : -7=

G)3T 7nter )utput Gower G (d6 : - 1.nter )utput Gower G1(d6 : -70.nter )utput Gower G8(d6 : - 1.@

G)3T 1nter )utput Gower G (d6 : - 1.nter )utput Gower G7(d6 : -7=

nter )utput Gower G8(d6 : - 1.@G)3T 8nter )utput Gower G (d6 : -7=nter )utput Gower G7(d6 : - 1.nter )utput Gower G1(d6 : - 1.

OUT3UT:9oupling %actor (d6 :

. ///Eirectivity (d6 :

1.7///*nsertion oss (d6 :

. ///*solation oss (d6 :

?S-matri+ of Eirectional 9oupler:

/ /. 7 /. 7 /. == /. 7 / /. 7/ /. /1? /. 7 /. == / /. /1? /. == /. 7 /. 7 /Expt. No.: S3ECTRA2 ANA2YSIS OF AM6FM AND FS USIN,

S3ECTRUM ANA2Y7ERDate:

19


20/62

AIM:

To study the spectrum of Modulation circuits li"e >M, %M and %S< by

using Spectrum >naly!er.

E8UI3MENTS RE8UIRED:

. Spectrum >naly!er

7. >rbitrary Baveform enerator

1. 7/ M$! dual )scilloscope

8. Multi-meter

?. 9onnecting Grobes

THEORY:

(0oc9 Dia*ra" o/ Spectr#" A$a0'-er:

The main components of Spectrum >naly!er are an 3% input

attenuator, input amplifier, mi+er, *% amplifier, *% filter, envelope detector,

video filter, 93T display, ), ramp generator.

ets describe each component individually *nput Section. The input to

the spectrum analy!er bloc" diagram has a step attenuator, followed by an

amplifier. The purpose of this input section is to control the signal levelapplied to the rest of the instrument. *f the signal level is too large, the

analy!er circuits will saturate the mi+er and distort the signal, causing

distortion products to appear along with the desired signal. *f the signal level

is too small, the signal may be mas"ed by noise present in the analy!er.

ither problem tends to reduce the dynamic range of the

measurement. The new instruments provide an auto range feature, which

automatically selects an appropriate input attenuation. The input circuitry ofa typical analy!er is very sensitive and will not withstand much abuse.

9areful attention should be paid to the allowable signal level at the input,

particularly for microwave analy!ers. Some instruments tolerate E9 voltages

at their

20


21/62

(0oc9 ia*ra" o/ &pectr#" a$a0'-er

IF Fi0ter a$ Se0ecti!it'

21


22/62

inputs, but others require that no E9 be applied, or be restricted to small

The front end of spectrum >naly!er is made with wide open on the basis

that we have no idea how many signals are involved in our measurement, in

order to control somehow on the measured spectrum, it is necessary to add

G% for image reFection.

Mixer

> mi+er is a device that converts a signal from one frequency to

another. *t is therefore sometimes called a frequency converter device. The

output of a mi+er consists of the two original signals f ) and f 3% as

well as the sum f ) Uf 3% and difference f ) -f 3% frequencies of

these two signals.

The *% filter is a 6and Gass %ilter (6G% which is used as the VwindowV

for detecting signals. *ts bandwidth is also called the 3esolution 6andwidth

(36, 36B of the analy!er and can be changed via the front panel of the

analy!er.

6y giving you a broad range of variable resolution bandwidth settings,

the instrument can be optimi!ed for the sweep and signal conditions, lettingyou trade-o. frequency selectivity (the ability to resolve signals , signal-to-

noise ratio (SA3 , and measurement speed. )ne of the first things to note is

that a signal cannot be displayed as an infinitely narrow line such as

mathematics ( delta function. *t has some width associated with it. This

shape is the analy!erKs tracing of its own *% filter shape as it tunes past a

signal. Thus, if we change the filter bandwidth, we change the width of the

displayed response. This concept enforces the idea that the *% filtersbandwidth and shape determines the resolvability between signals.

Bhen measuring two signals of equal-amplitude, the value of the

selected. 6B tells us how close together they can be and still be

distinguishable from one another (by a 1 d6 KdipK . $owever, with wider

6Bs, the two signals may appear as one. *n general then, two equal-

22


23/62

amplitude signals can be resolved if their separation is greater than or equal

to the 1-d6 bandwidth of the selected resolution bandwidth filter.

TA(U2AR CO2UMN:

A"p0it# e Mo #0atio$:

Modulation %requency: WWWWWW $! 9arrier %requency: WWWWWW $!

(a$ Fre%#e$c' +H-) 3o er 0e!e0 + (")

Fre%#e$c' "o #0atio$:

Modulation %requency: WWWWWW $!, 9arrier %requency: WWWWWW $!, %requency

Eeviation: WWWW $!

(a$ Fre%#e$c' +H-) 3o er 0e!e0 + (")

23


24/62

Si*$a0& o/ U$e%#a0 A"p0it# e

Se$&iti!it'

)ne of the primary uses of a spectrum analy!er is to search out and

measure low-level signals. The sensitivity of any receiver is an indication of

how well it can detects small

signals. > perfect receiver would add no additional noise to the natural

amount of thermal noise present in all electronic systems, represented byA N "T 6

where A is the noise power, " is 6olt!mannKs constant, T N temperature in

n input signal below this noise level cannot

be detected. enerally, sensitivity is on the order of -@/ d6m to - 8? d6m

depending on quality of spectrum analy!er. *t is important to "now the

sensitivity capability of your analy!er in order to determine if it will measure

your low-level signals.

)ne aspect of the analy!erKs internal noise that is often overloo"ed is

its selective level as a function of the 3% input attenuator setting . Since the

internal noise is generated after the mi+er (primarily in the first active *%

stage , the 3% input attenuator has no effect on the actual noise level.

$owever, the 3% input attenuator does affect the signal level at the input

and therefore decreases the signal-to-noise ratio (SA3 of the analy!er. The

best SA3 is with the lowest possible 3% input attenuation. This internally

generated noise in a spectrum analy!er is thermal in natureD that is, it is

24


25/62

random and has no discrete spectral components. >lso, its level is flat over a

frequency range that is wide in

comparison to the ranges of the 36Bs. This means that the total noise

reaching the detector (and displayed is related to the 3esolution bandwidth

selected.

Since the noise is random, it is added on a power basis, so the

relationship between displayed noise level and 3esolution bandwidth is a

ten log basis. *n other words, if the 3esolution bandwidth is increased (or

decreased by a factor of ten, ten times more (or less noise energy hits the

detector and the displayed average noise level increases (or decreases by

/ d6. Spectrum analy!er noise is specified in a specific 3esolution

CIRCUIT DIA,RAM:

FRE8UENCY SHIFT

EYIN,: MODE2 ,RA3H:

TA(U2AR CO2UMN:

FS Mo #0atio$:

9arrier %requency: WWWWWW $! $op %requency:

WWWWWW $!

(a$ Fre%#e$c' +H-) 3o er 0e!e0 + (")

25


26/62

bandwidth. The spectrum analy!erKs lowest noise level

(thus slowest sweep time is achieved with its narrowest

3esolution bandwidth.

Detector

Many modern spectrum analy!ers have digital

displays, which first digiti!e the video signal with an analog-

to digital converter (>E9 . This allows for several different

detector modes that dramatically effect how the signal is

displayed. )rdinary spectrum analy!er use pea"-detection

technique.

Vi eo Fi0ter

The video filter is a low-pass filter that is located after

the envelope detector and before the >E9. This filter

determines the bandwidth of the video amplifier, and is

used to average or smooth the trace seen on the screen.

The spectrum analy!er displays signal-plus-noise so

that the closer a signal is to the noise level, the more the

26


27/62

noise ma"es the signal more difficult to read. 6y changing

the video bandwidth setting, we can decrease the pea"-to-

pea" variations of noise. This type of display smoothing can

be used to help find signals that otherwise might be

obscured in the noise

The '6B, however, does not affect the frequency

resolution of the analy!er (>s does the resolution

bandwidth filter , and therefore changing the video filter

does not improve sensitivity. *t does, however, improve

discernibly and repeatability of low signal-to-noise ratio

measurements.

3ROCEDURE

Select the type of modulation.

Set the carrier frequency as a sine wave which can

range up to 7/ M$!

Set the hop frequency which is the modulating signal,

a square wave whose range is limited.

The output performance in frequency domain can be

viewed in the spectrum analy!er.

Similarly proceed for other modulations.

RESU2T:

Thus the spectrum of communication circuits li"e >M

and %M by using spectrum analy!er was studied.

AM32ITUDE MODU2ATION3RO,RAM CODE:clcD

clear allDAN7/8 DfsN7/8 DtN(/:(A- &fsDdisp(O nter the details of message signalO DvmNinput(O>mplitude(' : O DfmNinput(O%requency($! : O DwmN7XpiXfmDdisp(O nter the details of carrier signalO D

27


28/62

vcNinput(O>mplitude(' : O DfcNinput(O%requency($! : O DwcN7XpiXfcD'mNvmX(sin(wmXt D'cNvcX(sin(wcXt DmNvm&vcDam NvcXsin(wcXt U(mXvc&7 Xcos((wc-wm Xt -(mXvc&7 Xcos((wcUwm Xt Dam7N(mXvc&7 Xcos((wc-wm Xt -(mXvc&7 Xcos((wcUwm Xt Dfigure(subplot(8, , Dplot(t,'m Dtitle(OMessage SignalO D+label(OTime(sec O Dylabel(O>mplitude(' O Dsubplot(8, ,7 Dplot(t,'c Dtitle(O9arrier SignalO D+label(OTime(sec O Dylabel(O>mplitude(' O Dsubplot(8, ,1 Dplot(t,am Dtitle(O>mplitude modulated signalO D+label(OTime(sec O Dylabel(O>mplitude(' O Dsubplot(8, ,8 Dplot(t,am7 Dtitle(OEouble side band supressed carrierO D+label(OTime(sec O Dylabel(O>mplitude(' O Dmf Nabs(fft(am ,A DfNfsX(/:A&7 &ADfigure(7 Dsubplot(7, , Dplot(f( :7?0 ,mf ( :7?0 Dtitle(O%requency spectrum of >mplitude modulated signalO D+label(O%requency($! O Dylabel(OMagnitude(' O Dmf7Nabs(fft(am7,A Dsubplot(7, ,7 Dplot(f( :7?0 ,mf7( :7?0 D

title(O%requency spectrum of Eouble side band supressedcarrierO D+label(O%requency($! O Dylabel(OMagnitude(' O D

SAM32E IN3UT AND OUT3UT:IN3UT:

nter the details of message signal>mplitude(' : ?

28


29/62

%requency($! : /nter the details of carrier signal

>mplitude(' : /%requency($! : //

OUT3UT:

0 0 .1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 -5

0

5M e s s a g e S ig n a l

Tim e (s e c )

A m

p l i t u d

e ( V )

0 0 .1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 -1 0

0

1 0C a rrie r S ign a l

Tim e (s e c )

A m

p l i t u d

e ( V )

0 0 .1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 -2 0

0

2 0A m p litu d e m o d u la te d s ig n a l

Tim e (s e c )

A m p

l i t u d

e ( V )

0 0 .1 0 .2 0 .3 0 .4 0 .5 0 .6 0 .7 0 .8 0 .9 -5

0

5D o u b le s id e b a n d s u p re s s e d c a rrie r

Tim e (s e c )

A m

p l i t u d

e ( V )

29


30/62

0 50 100 150 200 250 3000

2000

4000

6000

8000

10000

12000Frequency spectrum of A m plitude m odulated signal

Frequency(Hz)

M a g n

i t u

d e

( V )

0 50 100 150 200 250 3000

50 0

1000

1500

2000

2500

3000Frequency spectrum of Double side band supressed carrier

Frequency(Hz)

M a g n

i t u

d e

( V )

30


31/62

FRE8UENCY MODU2ATION3RO,RAM CODE:clcDclear allDAN7/8 DfsN7/8 DtN(/:(A- &fsDdisp(O nter the details of message signalO DvmNinput(O>mplitude(' : O DfmNinput(O%requency($! : O DwmN7XpiXfmDdisp(O nter the details of carrier signalO DvcNinput(O>mplitude(' : O DfcNinput(O%requency($! : O DwcN7XpiXfcD'mNvmX(sin(wmXt D'cNvcX(sin(wcXt DmNinput(O nter the modulation inde+: O D+NvcXsin((wcXt U(mXsin(wmXt Dfigure(subplot(8, , Dplot(t,'m Dtitle(OMessage SignalO D+label(OTime(sec O Dylabel(O>mplitude(' O Dsubplot(8, ,7 Dplot(t,'c Dtitle(O9arrier SignalO D+label(OTime(sec O Dylabel(O>mplitude(' O Dsubplot(8, ,1 Dplot(t,+ Dtitle(O%requency modulated signalO D+label(OTime(sec O Dylabel(O>mplitude(' O Dsubplot(8, ,8 Dmf Nabs(fft(+,A DfNfsX(/:A&7 &ADplot(f( :7?0 ,mf ( :7?0 Dtitle(O%requency spectrum of %requency modulated signalO D

+label(O%requency($! O Dylabel(OMagnitude(' O D

31


32/62

SAM32E IN3UT AND OUT3UT:IN3UT:

nter the details of message signal>mplitude(' : ?%requency($! : /

nter the details of carrier signal>mplitude(' : /%requency($! : //

nter the modulation inde+: 7

OUT3UT:

0 0 .05 0 .1 0.15 0.2 0 .25 0.3 0 .35 0 .4 0 .45 -5

0

5M es s age S ignal

Tim e(s ec )

A m p

l i t u d

e ( V )

0 0 .05 0 .1 0.15 0.2 0 .25 0.3 0 .35 0 .4 0 .45 -1 0

0

10C arrier S ignal

Tim e(s ec )

A m p

l i t u d

e ( V )

0 0 .05 0 .1 0.15 0.2 0 .25 0.3 0 .35 0 .4 0 .45 -1 0

0

10F reque nc y m odula ted s ignal

Tim e(s ec )

A m p

l i t u d

e ( V )

0 50 100 150 200 250 300

2000

4000

6000F requen c y s pec trum o f F reque nc y m odulated s ignal

F reque nc y (H z )

M a g n

i t u

d e

( V )

32


33/62

FS MODU2ATION3RO,RAM CODE:clcDclear allDf/N //Df N1//DtN/:7Xpi&@@:7XpiDcpNQRDseNQRDbitNQRDmodNQRDmod NQRDgNQ / / / / / / / RDfor nN :length(g D if g(n NN/ dieNones( , // D cNsin(f/Xt D seN!eros( , // D else

dieNones( , // D cNsin(f Xt D seNones( , // D end cpNQcp dieRD modNQmod cRD bitNQbit seRDendfs"Ncp.XmodDsubplot(1, , Dplot(bit,O ineBidthO,7./ Dtitle(O6inary SignalO D+label(OTime(sec O Dylabel(O>mplitude(' O Da+is(Q/ //Xlength(g -7 7R Dsubplot(1, ,7 Dplot(fs",O ineBidthO,7./ Dtitle(O%S< modulationO D+label(OTime(sec O Dylabel(O>mplitude(' O Da+is(Q/ //Xlength(g -7 7R D

!Nabs(fft(+corr(fs" D+N/: //Dsubplot(1, ,1 Dplot(!,O ineBidthO,7./ Dtitle(OGower spectrum of %S< signalO D+label(O%requency($! O Dylabel(OGower(d6m O Da+is(Q/ // / . Xma+(! R D

33


34/62

OUT3UT:

0 200 400 600 800 1000 1200 140-0.5

0

0. 5

1

1. 5B inary S ignal

Tim e(sec)

A m p

l i t u d e

( V )

0 200 400 600 800 1000 1200 140

-1

0

1

FS K m odulation

Tim e(sec)

A m p

l i t u d e

( V )

0 10 20 30 40 50 60 70 80 90 1000

5

10

x 104 P ower spect rum of FS K signal

Frequency(Hz)

P o w e r (

d B m

) )

34


35/62

Expt. No.: MEASUREMENT OF S N AND C N USIN, SATE22ITE 2IN

DESI,NDate:

AIM:

To measure 9&A and S&A ratio using satellite lin" withthe uplin" frequency 7.8 $! and downlin" frequency

7.8 $!.


Satellite uplin" transmitter, satellite downlin"

receiver and satellite lin" emulator.

Gair of Cagi #da antennas and the 3$9G and $9G

a+ial mode heli+ antennas.>ntenna stands with connecting cables, mic, video

monitor, 99E cameras, functyion generator, 93),

spectrum analy!er.

FORMU2A:

%or


36/62

The signals have to be sent at different frequency,

usually in the higher 8 $! band, to avoid interference

with downlin" signals. >nother function performed by the

uplin" station is to control tightly the internal functions of

the satellite itself. #plin"s are controlled so that the

transmitted microwave power beam is e+tremely narrow, in

order not to interfere with the adFacent satellites in the geo

5 arc. The powers involved are several hundred watts.

36


37/62

Tra$&po$ er:

ach satellite has a number of transponder witch

access to a pair of receive & transmit antennas andassociated electronics for each channel. %or e+ample in

urope the uplin" sends a signal at a frequency of about 8

$!. These are received downlin" converted in frequency

of about & 7 $! and boosted by high power amplifier

for retransmission to earth. Separate transponder is used

for each channel and is powered by solar panels with

bac"up batteries for eclipse protection.

Sate00ite Do $ 2i$9:

The medium used to transmit signal from satellite to

earth is microwave electromagnetic radiation which is

much higher in frequency normal broadcast T' signal in

'$% & #$% bands. Microwave still e+hibit a wave li"e nature,

but inherit a tendency to serve attenuation by water vapors

or any obstruction in line of sight of antenna. The

transmitted micro wave power is e+tremely wea" by the

time it reaches earth and unless well designed equipment

is used and certain installation precaution are ta"en, the

bac"ground noise can ruin the signal.

3ROCEDURE:

37


38/62

To eter"i$e C N ratio:

Set up the lin" as before, press one frequency select

switch of satellite emulator downlin" channel several

time so as to set the frequency display from 7.8,

7.87=, 7.8?8, 7.8 and bac" to 7.8 $!. this is done

to ensure the emulator downlin" G is loc"ed and

displayed frequency is generated correctly. *f

switching )A the "$! test tone via satellite. G of

complete lin" are )< and a successful satellite is said

to be established.

Aow, switch )%% the carrier switching of both satellite

and transmitter.

3eceiver will read only its noise floor at 3SS* output

which has a E9 voltage output is proportional to the

received signal strength.

The chart can be used to connect E9 voltage to

corresponding 3% signal level in d6m or d6Z'.

Say in the absence of any carrier receiver reads

/.@7' which is equal to -@0d6m.

Thus -@0d6m is noise floor of receiver that means if

carrier received by receiver is less than -@0d6m.

TA(U2AR CO2UMN:

TRANSMITTER:

3at 0o&& Vo0ta*e +V) 3o er + () C N po er + ()Low

Medium

High

U32IN :


MediumHigh

38


39/62

DOWN2IN :


MediumHigh

RECEIVER:


MediumHigh

CONVERTIN, C N TO S N RATIO:

3at 0o&& C N 3OWER+ (") S N + ()U32IN DOWN2IN Low

MediumHigh

Switch )A transmitter and satellite, the receiver

reads .@ ' equal to -?@d6m of carrier level being

received.

9&A equal to carrier level&noise ratio as both noise

and carrier signal level detected are measured in d6.

9&A is equal to -?@-(-@0 N 1=d6m.

Ma"e sure receiver is not saturated with carrier

otherwise incorrect 9&A will be read.

Measure the 9&A readings of different levels of path

loss.

This means the received signal is Fust above the noise

floor of receiver.

RESU2T:

Thus the 9&A and S&A ratio using satellite lin" with the

uplin" and downlin" frequency has been measured.

39


40/62

To eter"i$e S N ratio:

Set up the lin" as similar to 9&A.

3emove 6A9 cables from video and digital in switch

enable of telecommand meaning.Measure the noise floor of all baseband output of

demodulator of receiver by removing all modulating

signal being fed transmitter and satellite lin"

emulator.

Aow, put audio or video signal into baseband of

transmitter so that modulated carrier will be

received.

>s both noise and modulating signal are measured

in m'.

Measure S&A by varying path loss at receiver.

*f video sent is received, it means the signal is

above threshold. This means the received signal is

above noise floor.

9onnect a Cagi #da antenna at receiver and with

same polarity of satellite downlin" station.

ain of Cagi #da antenna N 1d6i

ain of $eli+ antenna N d6i

stimated gain of antennas are ta"en into account

for losses due to mismatch and consequent SB3.

&T can be calculated as:

A> noise temperature N 7@/( / (nf& /- X< N

1?@<

&T N / log( /&1?@ N-

?d6&<

Minimum to ma+imum value of &T varies between

- /d6&


41/62

RESU2T:

Thus the 9&A and S&A ratio using satellite lin" with the

uplin" and downlin" frequency has been measured.

SATE22ITE 2IN DESI,N3RO,RAM CODE:

I#G *A<

41


42/62

GtNinput(O nter the arth station transmitted o&p power: O DboNinput(O arth station 6ac" off oss: O DbfNinput(O arth station 6ranching and %eeder oss: O D

ENinput(O nter the Eiameter: O DfNinput(O nter the %requency: O D

uNinput(O>dditional #plin" >tmospheric osses: O DT Ninput(O nter the Transponder 3atio: O D

%bNinput(O nter the Transmission 6it 3ate: O D>tN /Xlog /(.??X1. 8XEXfX /&1 D

pN 1.?U7/Xlog /(f D*3GNGtU>t- bo- bfD

9GEN *3G- p- uD9A3N9GEU T U77 .0D

bAo N9A3- /Xlog /(%b De N /P(. X bAo Dfprintf(O[n The >ntenna ain: IfO,>t Dfprintf(O[n The %ree Space Gath oss: IfO, p Dfprintf(O[n *3G: IfO, *3G Dfprintf(O[n 9GE: IfO,9GE Dfprintf(O[n 9A3: IfO,9A3 Dfprintf(O[n bAo : IfO, bAo D

IE)BA *A< Gt Ninput(O[n[n nter the satellite transmitted o&p power: O D

bo Ninput(OSatellite modulation 6ac" off oss: O Dbf Ninput(OSatellite 6ranching and %eeder oss: O D

E Ninput(O nter the Satellite Eiameter: O Df Ninput(O nter the Satellite %requency: O D

d Ninput(O>dditional Eownlin" >tmospheric osses: O DT Ninput(O nter the Transponder7 3atio: O D

%b Ninput(O nter the Transmission 6it 3ate: O D>t N /Xlog /(.??X1. 8XE Xf X /&1 D

p N 1.?U7/Xlog /(f D*3G NGtU>t - bo- bfD

9GE N *3G - p - d D9A3 N9GE U T U77 .0D

bAo7N9A3 - /Xlog /(%b De7N /P(. X bAo7 D%inNe Xe7&(e Ue7 Dfprintf(O[n The >ntenna ain: IfO,>t Dfprintf(O[n The %ree Space Gath oss: IfO, p D

fprintf(O[n *3G: IfO, *3G Dfprintf(O[n 9GE: IfO,9GE Dfprintf(O[n 9A3: IfO,9A3 Dfprintf(O[n bAo : IfO, bAo7 Dfprintf(O[n[n%inal bAo: IfO,%in DSAM32E IN3UT AND OUT3UT:

IN3UT:nter the arth station transmitted o&p power: 1/

42


43/62

arth station 6ac" off oss: 1arth station 6ranching and %eeder oss: 1nter the Eiameter: /nter the %requency: 8

>dditional #plin" >tmospheric osses: /.nter the Transponder 3atio: -8.0nter the Transmission 6it 3ate: @///////

OUT3UT: The >ntenna ain: 7@./07@@ The %ree Space Gath oss: 7/0.877?0 *3G: ?1./07@@ 9GE: - ?8. ?@?=/ 9A3: 0@. 8/81/ bAo : -@.=/ @@?

IN3UT:nter the satellite transmitted o&p power: /

Satellite modulation 6ac" off oss: /.Satellite 6ranching and %eeder oss: /

nter the Satellite Eiameter: /.?nter the Satellite %requency: 7

>dditional Eownlin" >tmospheric osses: /.0nter the Transponder7 3atio: .8nter the Transmission 6it 3ate: @///////

OUT3UT: The >ntenna ain: ?.1 1771 The %ree Space Gath oss: 7/0.877?0 *3G: [email protected] 1771 9GE: - 0=.01@11= 9A3: [email protected]/001 bAo : - /. =07

%inal bAo: /./?/?@0

Expt. No.: 3C TO 3C COMMUNICATION 2INDate:

43


44/62

AIM:

To connect the 3S717 ports of two computers using

optical fiber digital lin", transmit data from one G9 over this

lin" and receive the same data on the other G9.


in" 6 "it with power supply.

Gatch chords

meter %iber cable

@ pin E connector 9ables 5 7 Aos.

9omputer 5 7 Aos. (Minimum 9onfiguration .

THEORY:

Tra$&"itter:

Eata signals transmitted through pin1 of @-pin JEK

connector of 3S-717 9)M port are sent to pin of M>;717

and it converts these 3S-717 compatible levels of U@' or

-@' to /&? volt TT levels as given in table.

The output of M>;717 drives the GAG

transistor through a bias resistor of " ohm, to switch

on \*3 ESV and also visible E. $ere actually when theoutput of M>;717 is /' at that time the GAG

transistor will be conduct and the *3 E as well visible E

will glow.

>nd when the output of M>;717 is ?' at that time

the GAG transistor will not conduct it is in cut-off region. So,

at that time the *3 E as well the visible E will not glow.

$ere it uses laser diodes and Es for the transmitter. 6othhave their own advantages and disadvantages. 6ut Es

are more reliable and also cheap, so we will be using a E.

There are several different schemes for carrying out

the modulation function. These are respectively:

*ntensity Modulation, %requency Shift


45/62


46/62

46


47/62

reason for the popularity of *ntensity Modulation is its

suitability for operation with EOs. >n E can only

produce incoherent optical power. Since *ntensity

Modulation does not require coherence it can be used with

an E.

The E that we have used has the following

features:

*nfrared E

Ao optical design required

Suitable for G9 to Geripheral lin"s

Recei!er:

The *3 signals are detected by a photo diode (E .>

Ghoto Eiode is reverse biased L brea"s down when *3 light

falls on its Function .The detected TT level (/&?' signals

are coupled to pin / of M>; 717 *9 .These TT levels are

converted toU@'or -@' levels internally L output at pin =.

> visible E at pin = of M>;717 *9 indicated that

the signals are bagging received. Gin = is also connected to

pin 7 of pin @ JEK connector used for the serial port in the

G9, so that the data may be read .The optical signals

received by the photodiodes are in fact converted to

electrical pulses and both the G9s \thin"V that there is null

modem cable connected between them.

The 3eceiver component serves two functions. %irst,

it must sense or detect the light coupled out of the fiber

optic cable then convert the light into an electrical signal.Secondly, it must demodulate this light to determine the

identity of the binary data that it represents. *n total, it

must detect light and then measure the relevant

*nformation bearing light wave parameters. > 3eceiver is

47


48/62

generally designed with a Transmitter. 6oth are modules

within the same pac"age. The very heart of the receiver

is the means for sensing the light output of the fiber optic

cable. ight is detected and then converted to an electrical

signal. The demodulation decision process is carried

out on the resulting electrical signal. The light detection is

carried out by a photodiode. This senses light and converts it

into an electrical current.

3ROCEDURE:

Ma"e connections as per figure. 9onnect the power supply

with proper polarity to in" 6 "it. Bhile connecting this,

ensure that power supply is )%%.


49/62

Slightly unscrew the cap of E S%$=?0' (00/ nm

on "it. Eo not remove fiber into the cap. Aow tight

the cap by screwing it bac".

Slightly unscrew the cap of 3; photo transistor with TT logic output S%$?? '. Eo not remove the cap

from the connector. )nce the cap is loosened, insert

the other end of fiber into the cap. Aow tighten the

cap by screwing it bac".

9onnect TT )#T post of 3eceiver section to 9)M7

post on the "it (3S 717 section .

>fter putting )A one of the G9, go to ST>3T M A#,

G3) 3>MS, >99 SS)3* S, 9)MM#A*9>T*)A and

then 9lic" on $CG 3 T 3M*A> .

> new Bindow will open, where in you Eouble 9lic"

$CG 3T 3M, Two windows will open, one at the

bac"ground and another (small window with title

connection description which will be active.

nter the name in the bo+ by which you would li"e to

store your connection for e.g. (G97G9 and 9lic" )lso you could select the icon provided below. The

bac"ground window title will change to the name

provided by you.

Then specify connect using: by selecting Eirect to

9)M or port where your cable is connected and then

clic" on )


50/62

Glease chec" the port you have selected and the

ports you are connecting.

Aow window with title 9)M Groperties will appear

where port setting should be done as shown below

and clic" on )


51/62

%or 6it per second setting you could select them for

different speeds. Eo not e+ceed it above ?7// bps.

>fter the above settings you clic" )

window will be prompted having title Send %ile with

%ile Aame and Grotocol. See %* .

51


52/62

Select 6rowse for the file, which you would li"e to

send to the G9 connected, select the file and 9lic" on

)pen the file name and address will be displayed in

the small window. Then select the window will

be prompted having title 3eceived %ile with location

at which you want to store the received file and

receiving protocol. See %* .

Select 6rowse for the file, which you would li"e to

send to the G9 connected, select the file and 9lic" on

)pen the file name and address will be displayed in

the small window. Then select the same


53/62

)n the G9 from which the selected file to be

transmitted, clic" on S AE. > window will open

showing file transfer status. *mmediately at the

receiving G9 clic" 3eceive (otherwise Time out error

will be displayed and communication will fail . Cou

will see a window showing file is begin received in the

form of pac"ets. See %* .

>fter file is transferred both the windows in the

(transmitting L receiving G9s will close. 9hec" for

the received file in the folder where the file is stored.

53


54/62

RESU2T:

Thus the G9 to G9 communication has been

established using a fiber optic digital lin".

54


55/62

3C TO 3C COMMUNICATION THROU,H O3TICA2 2IN

TRANSMITTER:

3RO,RAM CODE:

clcDclear allDs Ninput(J nter the Te+t to be Transmitted: J Dpause( D

I)pening Gorts and Specifying its Groperties

s7Nserial(J9)M K Dset(s7,K6aud3ateK,@0//,KEata6itsK, ,KStop6itsK, , K)utput6ufferSi!eK, /8 ?=0 Dfopen(s7 Dfprintf(s7,s D

I9losing Gorts

fclose(s7 Ddelete(s7 Dclear(s7 Ddisp(J[n[nE>T> *S T3>ASM*TT EK D


nter the Te+t to be Transmitted: J9ollege StudentsK

E>T> *S T3>ASM*TT E

55


56/62

3C TO 3C COMMUNICATION THROU,H O3TICA2 2IN

RECEIVER:

3RO,RAM CODE:

clcDclear allD

I)pening Gorts and Specifying its Groperties

s7Nserial(J9)M K Dset(s7,K6aud3ateK,@0//,KEata6itsK, ,KStop6itsK, , K)utput6ufferSi!eK, /8 ?=0 Dfopen(s7 DdataNfscanf(s7 D

I9losing Gorts

fclose(s7 Ddelete(s7 Dclear(s7 Ddisp(JE>T> *S 3 9 *' E: K Ddisp(J[n[ndataK D


E>T> *S 3 9 *' E:

9ollege Students

56


57/62

Expt. No.: STUDY OF ,3S TRAINER MODU2EDate:

AIM:

To perform the e+periment using GS trainer module and

to determine the number of active satellite in the

geographical location.

To infer the data received from the satellite.

THEORY:

C0oc9 O&ci00ator:

*t generates $! cloc" pulse. %or generation of $! cloc"

pulse timer *9???. # is used in astable mode. The 39

combination is used as per the values derived using the

formulas,

output of # is given to the invereter # (*9=8 S=8 across the

input and output of which 6i-color E ( is used for the

indication. )utput of # is ta"en cloc" input for # 7 (*9=8 S1@1 .

Di!i e 5' 5; Circ#it:

6inary counter # 7 (*9=8 S1@1 is used to divide the $!

cloc" pulse from oscillator section by b8. The output of binary

counter is used as input for # 1 (*9=8 S 71 .

Mo$o&ta50e M#0ti!i5rator:

)utput of monostable negative triggerable multivinrator ' 1

(*9=8 S 71 is used to reference pulse to cone of the inputs of

>AE gate ' 8 (*9=8 S/ second input for ' 8 is received from

transmitted output of GS receiver.

(eeper Recei!er:

Transmitter ] and ] 7 (7A1@/8 are used in as Earlington

pair for driving the beeper and 9E ( S . This is a audio visual

indication for self chec" cycle of GS receiver.

57


58/62

,3S Recei!er:

> typical receiver consists of the following components >ntenna (usually microstrip

ow noise 3% amplifier

9ode demodulators

6an" of correlators (one of each channel upto 7

mbedded microcontroller

Gower conditioner

58


59/62

Si*$a0 3roce&&i$*: The receiver demodulates the navigation message

superimposed on the carrier. 6y the time the signal reaches the

receiver, it is attenuated by 0/ d6. The resulting low signal

level requires an antenna and amplifier as ahown in the bloc"

59


60/62

diagram. The antenna and amplifier are termed to frequency

and enough bandwidth to pass the respective signal.

Co e De"o #0atio$:

*t is accomplished by a costers loop. That is by multiplying

the incoming signal by a relica of the carrier generated by a

local oscillator. *f the phase of the local oscillator does not

e+actly match the phase of the carrier, error occurs. Therefore

the phase of 9 is more adFustable to trac" the carrier phase.

The output of the costers loop is the navigation message

superimposed on the GA code. Therefore the GA code must be

removed. This is accomplished by correlating the received GA

code with a locally generated replica of GA code after phase

synchroni!ation.

3o&itio$i$* So/t are:

The embedded microcontroller may implement the

following functions: 9orrelation&synchroni!ation

%etching the navigation message

9alculating positioning information

Storming data %ormatting data

)utputting data on a serial port of computer

interfacing

RS


61/62

Start the GS trainer module.

9hec" for GS fa+ availability.

9lic" start to view the active and passive satellite.

Then clic" the SA3 plot, to "now the SA3 value of all

active satellite.

o to survey to "now the latitude and longitudinal position

of the satellite.

9hec" the A>'* >T*)A report, to "now thedistance of the

satellite from the sea level.

RESU2T:

Thus the e+periment for GS trainer module, to determinethe number of active satellite and infer data received from the

satellite was performed.

61


62/62

advanced communication laboratory final manual

Documents