ScienTECH 2261 User manual

AntennaTrainer
Scientech2261
ProductTutorial
Ver1.1
Designed&ManufacturedinIndia by-
\AnISO9001:2008company
ScientechTechnologiesPvt. Ltd.
94,ElectronicComplex, Pardesipura,Indore-452010India,
[phone], : [e-mail] , : www.ScientechWorld.com

Scientech2261
2
AntennaTrainer
Scientech2261
TableofContents
1. SafetyInstructions5
2. Introduction6
3. Features7
4. TechnicalSpecifications8
5. TrainerDescription9
6. BasicAntennaConcept13
7. RadiationMechanismandEvolutionofDipole15
8. StandingWaveRatio16
9. DirectionalCoupler17
10. AntennaMatching18
11. ImportantCharacteristicsofAntenna20
12. RadiationResistance 20
13. RadiationPattern21
14. PolarPlots21
15. BeamWidthandGainofMainLobe22
16. PositionandMagnitudeofSideLobes23
17. Bandwidth23
18. FronttoBackRatio23
19. Aperture/CaptureArea 24
20. PolarisationofElectricField24
21. Experiments
·Experiment125
Arrangingthesetup andperforming thefunctionalchecksof
Antennasystem
·Experiment227
Toperformmodulationanddemodulationtest
·Experiment328
PlottingthePolargraph/radiationpatternofanAntennamanually
·Experiment432
PlottingthePolargraph/radiationpatternofanAntennausing software
·Experiment536
StudyofSimpleDipole(l/2)antenna

Scientech2261
3
·Experiment639
StudyofSimpleDipole l/4antenna
·Experiment742
StudyofFoldedDipole l/2antenna
·Experiment845
StudyofSimpleDipole(3l/2)antenna
·Experiment948
StudyofYagi-UDA5ElementSimpledipoleantenna
·Experiment10 51
StudyofYagi-UDA3ElementFoldeddipoleantenna
·Experiment11 54
StudyofYagi-UDA5ElementFoldeddipoleantenna
·Experiment12 57
StudyofYagi-UDA7ElementSimpledipoleantenna
·Experiment13 60
StudyofHertzantenna
·Experiment14 63
StudyofZeppelinantenna
·Experiment15 66
Studyof l/2PhaseArray(Endfire)antenna
·Experiment16 69
Studyof l/4PhaseArray(Endfire)antenna
·Experiment17 72
StudyofCombinedCo-linearArrayantenna
·Experiment18 75
StudyofBroadSideArrayantenna
·Experiment19 78
StudyofLogPeriodicantenna
·Experiment20 81
StudyofCutParaboloidReflectorAntenna
·Experiment21 84
StudyofLoopAntenna
·Experiment22 87
StudyofRhombusantenna
·Experiment23 90
StudyofGroundPlaneantenna
·Experiment24 93
StudyofSlotantenna

Scientech2261
4
·Experiment25 96
StudyofHelixAntenna
·Experiment26 99
ToperformPolarisationTest
·Experiment27 101
Studyofvariationintheradiationstrengthatagivendistance from
theantenna
·Experiment28 102
StudyoftheReciprocitytheoremforantennas
·Experiment29 103
StudyofMatching Stub
·Experiment30 105
SWRMeasurement
·Experiment31 106
Antennacurrentsensor
22. µAtodBµAConversionChart109
23. Warranty110
24. ListofAccessories(FullUnit)111
25. ListofAccessories(10 Antenna)113
26. ListofAccessories(BaseUnit)114

Scientech2261
5
SafetyInstructions
Readthefollowing safetyinstructionscarefullybeforeoperatingtheproduct.
Toavoidanypersonalinjuryordamagetotheproduct,oranyproductsconnectedto
it;
Donotoperatetheinstrumentifyoususpectanydamagewithin.
Theinstrumentshouldbeservicedbyqualifiedpersonnelonly.
ForyourSafety:
UseproperMainscord:Useonlythemainscorddesignedforthisproduct.
Ensurethatthemainscordissuitableforyour
country.
Ground theInstrument:Thisproductisgroundedthroughtheprotectiveearth
conductorofthemainscord.Toavoidelectricshock
thegroundingconductormustbeconnectedtothe
earthground.Beforemaking connectionstotheinput
terminals,ensurethattheinstrumentisproperly
grounded.
ObserveTerminalRatings :Toavoidfireorshockhazards, observeallratingsand
marksontheinstrument.
UseonlytheproperFuse :Usethefusetypeandratingspecifiedforthisproduct.
UseinproperAtmosphere :Pleaserefertooperatingconditionsgiveninthe
manual.
1. Donotoperateinwet/dampconditions.
2. Donotoperateinanexplosiveatmosphere.
3. Keeptheproductdustfree, cleanand dry.

Scientech2261
6
Introduction
ScientechAntennaTrainer, Scientech2261; isastudentfriendlytrainerkitfor
studyingcharacteristicsofdifferentantennas.Thetrainerisdesignedsothatstudents
cantakethereadingsandplotthepolarplotsthemselves,thusunderstanding the
subjectthoroughly. Theycanevenstop&repeatthereadingsinbetweenifneeded.
Alltheantennasaremadebyhighconductingrodswithchromefinishforlong
durabilityandmountedontheglass epoxyPCBforeasymountinganddismounting.
AreasofExperimentationandStudy:
·Polarplot&PolarizationofvariousAntennas
·WaveModulationandDemodulation
·AntennaGain
·AntennaBeamWidth
·ElementCurrentStudy
·FrontBackRatioStudy
·AntennaMatching
·SWRMeasurement
·AntennaRadiationwithDistance.
AntennaTrainer

Scientech2261
7
Features
·SelfContainedSimpleand StudentFriendlyTrainer.
·LowCost.
·Handsonset-up formeasuringand plottingradiationpatternsof20
differentAntennas.
·OnboardRF&ToneGenerators.
·AntennaMatchingStub.
·Characteristicsand SWRMeasurement
·Transmittingand ReceivinglevelsobservedOnBuilt- inMeters.
·FunctionalBlockindicatedOn-boardMimics.
·BuiltinDC PowerSupply.
·FullyDocumentedOperatingManualand PolarChartswitheachTrainer.
·“Antennakit”forfabricatingSpecialAntenna.
·CompactDesign.
·Lightweight.

Scientech2261
8
TechnicalSpecifications
RFGenerator :750 MHzapproximately(onboardadjustablewith
leveldisplay)
ModulationGenerator: 1KHzapproximately(Onboardwithleveladjustfor
modulation)
DirectionalCoupler: Forward&Reverse(Onboardselectable)
MatchingStub :SlideStub
AntennaRotation :0-360 Degrees,Resolution1Degree Transmitting &
Receivermastsprovided
Receivingantenna :FoldedDipolewithreflector
DetectorDisplay:Onboardleveladjustablemeter
PowerSupply :230V±10%, 50Hz
PowerConsumption: 3VA(approximately)
Interconnections:BNC
Dimensions(MainUnit): 385×285×75mm
Weight :3.5Kgs. approximately

Scientech2261
9
TrainerDescription
Thetrainerconsistsof:
·MainUnit
·TransmittingMast
·Receiving Mast
·RFDetector
·AccessoriesCasecontaining Antennas(22 types)
·Matching Stub
·OtherAccessories
Themainunitisdesignedfordesktopusewithscreenprintonfrontpanelshowing
trainermimicdiagram. See figure1.
Themainunitconsistsof:
·RFGenerator
·ModulationGenerator
·DirectionalCoupler
MainUnit

Scientech2261
10
RFGenerator
Itdeliversatestsignaltofeedtheantennasundertest. TheRFGeneratoroperatesata
frequencyof750 MHzapproximately.Thereasonbeing reducedsize forantennas.
Thehigheristhefrequency, thesmalleristhesizeoftheantennasandthesizeofthe
trainerasawhole. Thisgivestheadvantageofahandiestoperationofthesystemona
testdeskofalaboratory.
TheRFgeneratorfeaturesthefollowing:
1. Knobadjustableoutputpowerlevel.
2. Facilitiestomatchdifferentloads.
3. Modulatinginput(AM)whichcanbeusedwiththeonboardmodulation
generator.
4. Capabilitytostandindefinitelyevenheavilymismatchedoutput(shortoropen).
Inextremecasesthegeneratorstopsoscillationsandlatchesup inprotection.
Normaloperationisrestoredbytakingthelevelknobtozeroorswitchoff the
powerandagainswitchon.
Modulationgenerator:
Thisprovidesamplitudeadjustablesinewave(approximately2Vpp,1KHz)for
modulationoftheRFgenerator.
Directionalcoupler:
Thisallowsseparatemeteringofpowerflowing intheforwarddirection(generatorto
antenna)andthereversedirection(antennatogenerator).Thisisusedduring the
experimentsasanaidtomatchthegeneratortotheloadandalsoasameansto
measurethe Standing Wave Ratio inthetransmissionlinetotheantennas.
Matchingstub:
Thisisatrunkofthetransmissionline,whichisgivenseparatelyprovidedwitha
slidecursorshorteningthelineatpresetablelengthfromtheotherend(input).
RFDetector:
Thisisusedtodetectandmeasuretheradiationpatternoftheantennasunderstudy.
(See figure2.)
Thefeaturesofthedetectorarethefollowing:
1. Completelypassiveinstruments.
2. Adapter(+7.5-9V)isgivenforDPM (Digitalpanelmeter).
3. ThetabletopRFDetectorcanbedirectlyconnectedtoreceiving mastbyusing
aBNCtoBNCcableof25”long. See thefigure4forsetup.
4. Detectorantennaisconsistsofafoldeddipoleantennaasreceiving elementand
areflectortoreduce possibledisturbancetothemeasurementduetoreflection
ofwavesfromobjectsandlaboratorywallsbehindthedetector.
5. Displayreadingscanbeadjustedbyvarying ‘Level’knob.