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Antennas for GSM System
Contents
Base station antenna specification and meanings
Antenna types and trends
(Technical Data)
B lah
blahb la h bl ah
( Electrical properties )• Operation Frequency Band• Input impedance• VSWR• Polarization• Gain• Radiation Pattern• Horizontal/Vertical beamwidth • Downtilt• Front/back ratio• Sidelobe suppression and null filling• Power capability• 3rd order Intermodulation• Insulation
( Mechanical properties )• Size• Weight• Radome material• Appearance and color• Working temperature• Storage termperature• Windload• Connector types• Package Size• Lightening
Electrical properties
Wavelength
1/2 Wavelength
1/4 Wavelength
1/4 Wavelength
1/2 Wavelength
Dipole
( Dipoles )
1800MHz : 166mm
900MHz : 333mm
1 个 dipole (received power) : 1mW
Multiple dipole matrixReceived power : 4 mW
GAIN= 10log(4mW/1mW) = 6dBd
Gain=10log(8mW/1mW) = 9dBi
Sector antennaReceived power : 8mW
Omni directional arrayReceived power : 1mW
(Overlook)
Antenna
( Frequency Range )
• GSM 900 : 890-960MHz• GSM 1800 : 1710-1880MHz• GSM dual band : 890-960MHz &
1710-1880MHz• eg.824-960MHz , 1710-
1900MHz
( BANDWIDTH ) = 960 - 890 = 70MHz
Optimum 1/2 wavelengthfor dipole at 925MHz
at 960MHz
Antenna Dipole
at 890MHz
( Impedance )
• 50
Cable
50 ohms
Antenna 50 ohms
9.5 W80
ohms50 ohms
Forward: 10W
Backward: 0.5W
Return Loss : 10log(10/0.5) = 13dB
VSWR (Voltage Standing Wave Ratio)
( VSWR )
1.5=(VSWR-1)/(VSWR+1)RL=-20lg
( Polarization )
Vertical Horizontal
+ 45degree slant - 45degree slant
V/H (Vertical/Horizontal) Slant (+/- 45°)
( Linear,vertical )( dual linear 45 slant )
Dipole
Ideal radiating dot source(lossless radiator)
eg: 0dBd = 2.15dBi
dBd and dBi
2.15dB
( Pattern )
( Beamwidth )
120° (eg) Peak
Peak - 10dB
Peak - 10dB
10dB Beamwidth
60° (eg) Peak
Peak - 3dB
Peak - 3dB
3dB Beamwidth
( 3dB Beam width Horizontal )
• Directional Antenna : 65°/90°/105°/120 °Omni : 360°
( 3dB Beam width Vertical )
Directional : Omni-directional :
( Down Tilt )
Mechanical down tiltFixed electronic down tiltAdjustable electronic down tilt
Demonstration of Electronic Down-tilt
Non down tilt Electronic downtilt Mechanical downtilt
(Electronic and mechanical downtilt)
( Front to Back Ratio )
Ratio of maximum main lobe to maximum side lobe
F/B = 10 log(FP/BP) typically : 25dB
Back power Front power
( Upper Side lobes Suppression & Null Fill )
( Side lobes )
( Permitted Power )
Continuous :25-1500 watts
peak :n2p
( Third Order Intermodulation )
IMD@243dBm f1, f2, 2f1-f2, 2f2-f1
913MHz,936MHz,959MHz,982MHz
1000mW ( 1W) 1mW
10log(1000mW/1mW) = 30dB
( Isolation )
Mechanical properties
( Dimensions )
LWHLength : connected with vertical bandwidth and
gainWidth : connected with horizontal bandwidthHeight : connected with techniques adopted
( Weight )
Affecting transmission and deploy
( Radome Material )
PVC, FiberglassAnti-temperature 、 water-proof , anti-
aging , weather resistant
( Colour )Good-looking,
environment-protecting
( Operating Temperature Range )
Typical range : -40°C — +70°C
( Storage Temperature Range )
Typically : -40°C — +70°C
( Wind Load )
Eg: 83N at 160 km/h
( Connector Type )
7/16”DIN , N , SMA female
( Mast )
Mast diameter 45-90mm
( Lightening Protection )
Direct Ground
(Antenna Types and Development )
(Antenna Types)By frequency band: GSM900, GSM1800, GSM900/1800
By polarization: Vertical, Horizontal, ±45º linear
polarization, circle polarization
By pattern: Omni-directional, directional
By down-tilt: Non, mechanical, electronic
adjustment, remote control
By function: Transmission, receiving, transceiving
(Antenna Development Trend)
Broad bandMultifunctionalHigh Integrity
ONE ANTENNA FOR MULTIPLE BANDS
870-960MHz and 1710-1880MHzExtended band option with 806-960MHz Dual slant ±45º polarisation65º horizontal beamwidthBand independent Teletilt™ control17dBi gain in both bandsDiplexed or Non-Diplexed versionsMechanical downtilt mounting option
7/8” ( MAIN FEEDER )
1/2” ( JUMP CABLE )
7/16”DIN-F ( DIN CONNECTOR )
7/16”DIN-M ( DIN & N CONNECTOR )
Lightening Arrestor
Rf port 2
Grounding
( ACCESSORIES )( Trimming Tool or Hand Tool Kit )( Clamp )( Earthing Kit )( Wall Glands )( Hoisting Stocking ) ( Universal Ground Bar)
Antenna
7/16 Din Connector
7/8“ Cable
Grounding
1/2“ Jumper
Cabinet
EMPGrounding clip
Grounding bar
1/2 Clamp
Tower Top Amplifier
7/8“ Cable
Machine house
1/2 Jumper
Thank you