Basic Knowledge of Antenna and Antenna Selection

Radio Network Planning & Optimization DepartmentMobile Institution1V1.020077PurposeAfter learning this course you will be able to:Know the concept of dipolesUnderstand basic properties of antennaMater the principle of antenna selection 2IndexOutline of antennaTechnical dataTypes of antennas and their development trendPrinciple of antenna selection

3make optimize projectNetwork optimizationCollect data informationDeal optimize projectRegulate and verifyAntenna optimizationOptimize cover rangeAverage calling missionImprove calling qualityImprove network running qualityThe function of antennaOutline of antenna4Antenna is the conversion for circuit signal of communication equipment to radio in the air like the bridge tower.

Antenna is the key equipment for the sending and receiving of radio.

The gain, covering direction, beam, available driver power, configuration and polarization function will affect the communication.

Outline of antennaThe outline and function of antenna 5Wavelength1/2 Wavelength1/4 Wavelength1/4 Wavelength1/2 WavelengthDipole

1800MHz 166mm 900MHz 333mm Dipole Outline of antenna6

One dipoleReceive power1mwn dipolesReceive power4mwGAIN= 10log(4mW/1mW) = 6dBdDipole Outline of antenna710log(8mW/1mW) = 9dBdSector antenna Receive power : 8mWOmnidirectional array Receive power :4mW(top view)AntennaDipole Outline of antenna8IndexOutline of antennaTechnical dataTypes of antennas and their development trendPrinciple of antenna selection

9GSM 900 DCS 1800 GSM900+DCS1800 CDMATechnical dataElectrical properties--frequency

10 BANDWIDTH = 960 - 890 = 70MHzOptimum 1/2 wavelengthfor dipole at 925MHzat 960MHzAntenna Dipoleat 890MHzElectrical properties--frequencyTechnical data1150

Cable

50 ohmsAntenna 50 ohmsElectrical propertiesinput impedanceTechnical data12

9.5 W50 ohmsforward: 10Wbackward: 0.5WReturn Loss 10log(10/0.5) = 13dBVSWR (Voltage Standing Wave Ratio)Electrical propertiesvoltage standing wave ratio

Technical data13

VSWR1.5

=(VSWR-1)/(VSWR+1)

VSWR=(1+ ||)/(1-| |)

RL=-20lg ||Electrical propertiesvoltage standing wave ratioTechnical data14

VerticalHorizontal+ 45degree slant- 45degree slantElectrical propertiespolarize modeTechnical data15

V/H (Vertical/Horizontal)Slant (+/- 45)Electrical propertiespolarize modeTechnical data16Linear,verticadual linear 45 slant

Electrical propertiespolarize modeTechnical data17Antenna radiant energy collection degree and the energy conversion efficiencyG=4 U/PA unitdBiG= GA/ GA0 unitdBd0dBd=2.15 dBi

Electrical propertiesgainTechnical data18dipoleidea point fountainzero waste equality radiationeg: 0dBd = 2.15dBi

dBd and dBi

2.15dBElectrical propertiesgainTechnical data19

Electrical propertiesgainTechnical data20120 (eg)PeakPeak - 10dBPeak - 10dB10dB Beamwidth60 (eg)PeakPeak - 3dBPeak - 3dB3dB BeamwidthElectrical propertieswave widthTechnical data21

Electrical propertieswave widthTechnical data22Sector antenna 30/65/90/105/120 omni-antenna 360Electrical propertieswave widthTechnical data

23

Electrical propertieswave widthTechnical data24

horizontal 3dB beam width 3dB width choose graphElectrical propertieswave widthTechnical data25No declinationMachine declinationFixed electrical declinationMeasurable electrical declinationRemote control declinationMachine electrical combine use

Electrical propertiesdeclinationTechnical data26

Electrical propertiesdeclinationTechnical data27

Electrical propertiesdeclinationTechnical data

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No declinationElectrical declinationMachine declination

Electrical propertiesdeclinationTechnical data29

Electrical propertiesdeclinationTechnical data30The max value of main petal to the max value of back petal ratioF/B = 10 log( front power / back power ) typically 25dB

Back powerFront powerElectrical propertiesFront to Back Ratio Technical data31

Electrical propertiespetal restrain & zero point fillTechnical data32Down assistant petal (dB)Up assistant petal (dB)

Electrical propertiespetal restrain & zero point fillTechnical data33Continuous :25-1500watts

peak :n2p

Electrical propertiespower capabilityTechnical data341000mW ( 1W)1mW10log(1000mW/1mW) = 30dB

For multi-port antenna using, the isolation degree between every port must be bigger then 30dBElectrical propertiesisolateTechnical data35The same frequency, different frequency, dual-frequency antenna port>30dB

Electrical propertiesisolateTechnical data36Length width highlengthrelate with vertical petal, gainwidthrelate with horizontal petalhighrelate with the technology of antenna

Mechanism properties parameterTechnical data37PVC, ABS, fiberglass etc.Prevent from bask, freeze, salt fog, burning and aging.

Mechanism properties parameter materialTechnical data38good look, environment protection

Mechanism properties parameter appearance colorTechnical data39type value-40C+70C

Mechanism properties parameter working degreeTechnical data40For example: 83N at 160 km/h

Mechanism properties parameter wind carryTechnical data41The smaller the better

Mechanism properties parameter windwardTechnical data427/16DINNSMAfemale

Mechanism properties parameter tie-inTechnical data43Mast diameter 45-90mm

Mechanism properties parameter hold poleTechnical data44

Mechanism properties parameter thunder resistantTechnical data45index

Outline of antennaTechnical dataTypes of antennas and their development trendPrinciple of antenna selection

46According to frequencyGSM900GSM1800GSM900/1800 dual-frequency According to polarization Vertical45liner polarizelevelcircularity polarizeAccording to direction chartOmni-antennasector antenna According to declination mode nomechanismfixed electrical measurable electrical remote control According to function sendreceivesend-receive together Types & developmentkinds of BTS antenna47

develop trendWidth frequency bandMulti-functionHigh integrated

Types & development48

GSM900/1800 dual-frequency and dual-polarizeRemote control isolate electrical declination antennadevelop trend Types & development49C 900/1800C 900/1800+45/900 +45/1800 -45/900 -45/1800+45/900 -45/900 +45/1800-45/1800

develop trend Types & development50index

Outline of antennaTechnical dataTypes of antennas and their development trendPrinciple of antenna selection

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principle of antenna selectionRadio environment for suburb/country52Polarize modAs it is hard to choose BTS address and space for antenna, the dual-polarize antenna need to be chosedirection chatAccording duplicate using of frequency, sector antenna need to be chose3dB Power Beam widthFor controlling the cover range to restrain disturb, the horizontal plane 3dB power beam width of antenna in urban should be 60~65antenna gainThe gain of antenna, which should be used in urban, is 15-16dBi. The antenna with lower gain could be used to cover the blind urban area.Declination degreeDown tilt antenna is suggested, and electrical declination antenna in sometimes.Characteristics of application environment:When The distribution of BTS is dense, the cover range of single BTS need to be small, the over cover phenomena and the disturb between BTS need to be decreased, the duplicate using of frequency need to be increased.antenna choose for urban principle of antenna selection53

Radio environment for urban principle of antenna selection54Characteristics of application environment: Environment around should be considered in Sparse distributing, low traffic, larger coverage situation.Polarize modChoose vertical polarize or dual-polarize antennadirection chatThe sector antenna with 90or 105horizontal plane 3dB power beam width is used.3dB Power Beam widthThe omni-antenna with 90or 105horizontal plane 3dB power beam width or wider is used.antenna gainThe antenna with high gain is suggested, which is 16-18dBi for sector antenna or 911dBi for omni-antenna in rural and suburb area.Declination degreeMechanism declination is suggested. The zero fill antenna is needed when the high level of antenna is greater then 50 meters to avoid dark under antenna phenomenon.antenna choose for suburb/country principle of antenna selection55

Radio environment for highway principle of antenna selection56Characteristics of application environment:Low traffic, high speed moving The covering problem is the key issue. For strap covering, dual-cell coverage is needed. Sometimes, the omni-cell is used in some spots.Polarize modChoose vertical polarize or dual-polarize antenna according to particular situationdirection chatTo cover railway and road, the narrow beam width and high gain antenna should be used.3dB Power Beam widthThe gain of sector antenna is higher, the horizontal plane 3dB power beam width is about 30 antenna gainThe gain of sector antenna should be 18dBi22dBi, and omni-antenna is 11dBi Declination degreeDown tilt is not needed for highway covering, and the mechanism declination antenna is suggested.antenna choose for highwayprinciple of antenna selection57

Figure 6.5 beauty spotRadio environment for mountainous area principle of antenna selection58Characteristics of application environment:in the knap out of the way, serious mountain block, big radio pass losshard to cover area. Polarize modChoose vertical polarize or dual-polarize antenna according to particular situationdirection chatChoose omni-antenna or sector antenna3dB Power Beam width For BTS built on the mountain, if the level of cover area is low, the antenna with bigger 3dB power beam width need to be chose antenna gainChoose middle antenna gain according to the distance of cover area, omni-antenna(9-11dBi), sector antenna(15-18dBi)Declination degreeIf BTS be built on the mountain, when the cover area is under the mountain, the antenna with zero point filling or declination need to be choseantenna choose for mountainous area principle of antenna selection59Thanks!60