6.antenna introduction(v0.1).pdf
TRANSCRIPT
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 1/50
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 2/50
2
CDMA
Antenna Introduction
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 3/50
3
Syllabus¾ BTS Antenna System
Introduction¾ Antenna Diversity
¾ Electrical properties
¾ Mechanical properties
¾ Antenna Development
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 4/50
4
BTS Antenna System Introduction
antenna
7/16 Tie-in
1/2“ cable
7/8“ cable1/2 cable
BTS
arrester
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 5/50
5
Syllabus¾ BTS Antenna System
Introduction¾ Antenna Diversity
¾ Electrical properties
¾ Mechanical properties
¾ Antenna Development
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 6/50
6
Antenna DiversitySpace Diversity
Space Diversity:
when there exist certain space between tworeceiving antennas,they can receive the same signal with
different fading envelope . and if the correlation coefficient is
less than 0.7, the diversity receiving requirement is met.
Space Diversity requires :
D>10λ h/D≤11
Where H : the height of the antenna.D : the distance between two antennas
Space Diversity is only used in horizontal
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 7/50
7
Polarization Diversity
Polarization Diversity can be
obtained if dual polarization (+
45° /- 45°) antenna is used at each
sector of each carrier
Antenna Diversity
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 8/50
8
Syllabus¾ BTS Antenna System
Introduction
¾ Antenna Diversity
¾ Electrical properties
¾ Mechanical properties
¾ Antenna Development
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 9/50
9
Electrical properties
Blah blahblah bl ah
Frequency Range
Impedance
Dipoles Polarization
Gain
VSWR Beamwidth
Downtilt
PatternElevation Upper Side lobes & Null Fill
Third OrderInter modulation
Front to Back Ratio Isolation
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 10/50
10
Wavelength
1/2 Wavelength
1/4 Wavelength
1/4 Wavelength
1/2 Wavelength
Dipole
1800MHz :166mm
900MHz :333mm
Dipoles
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 11/50
11
One dipoleReceived Power:1mW
multiple dipolesReceived Power:4 mW
GAIN = 10log(4mW/1mW) = 6dBd
Dipoles
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 12/50
12
10log(8mW/1mW) = 9dBd
Sector antennaReceived Power:8mW
Omnidirectional arrayReceived Power:4mW
(down look)
Antenna
Dipoles
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 13/50
13
Frequency Range
For CDMA1900 system, the frequency
range of antenna can be 1850-1990MHZ
For CDMA800 system,the frequency range
of antenna can be 824-896MHZ
For GSM900 system,the FrequencyRange of antenna can be 890-960MHz、
870-960MHz、807-960 MHz or 890-1880
MHz.
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 14/50
14
BANDWIDTH = 896 - 824 = 72MHz
Optimum 1/2 wavelength
for dipole at 860MHz
at896
MHz
AntennaDipole
at824
MHz
The Frequency Range of antenna inCDMA800M system
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 15/50
15
Impedance
50Ω
Cable
50 ohms
Antenna
50 ohms
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 16/50
16
9.5 W80
ohms50 ohms
forward: 10W
reverse: 0.5W
Return Loss:10log(10/0.5) = 13dB
VSWR (Voltage Standing Wave Ratio)
VSWR
576.12236.01
2236.01
1
1VSWR
10
5.0
=−
+
−
+
=
==
ρ
ρ
ρ
Usual Request:VSWR<1.5
Reflection Coefficient:Γ=(VSWR-1)/(VSWR+1)
Return Loss:RL=-20lg Γ
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 17/50
17
Polarization
Vertical Horizontal
+ 45degree slant - 45degree slant
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 18/50
18
V/H (Vertical/Horizontal) Slant (+/- 45°)
Polarization
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 19/50
19
Linear,vertical
Polarization
dual linear ±45 ° slant
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 20/50
20
Gain
Ratio of antenna power density at adistant point relative to that of an
isotropic radiator as the two input power
values are the same.
Unless otherwise specified, the gain
usually refers to the direction of
maximum radiation.
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 21/50
21
Antenna gain is usually expressed in dBi or dBd
dBiGain relative to an isotropic antenna when the
reference antenna is an isotropic antenna.
dBd
Gain relative to a half-wave dipole when the
reference antenna is a half-wave dipole.
Gain
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 22/50
22half-wave dipole
isotropic radiator
eg: 0dBd = 2.15dBi
2.15dB
Gain
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 23/50
23
Pattern
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 24/50
24
120° (eg) Peak
Peak - 10dB
Peak - 10dB
10dB Beamwidth
60° (eg) Peak
Peak - 3dB
Peak - 3dB
3dB Beamwidth
Beamwidth
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 25/50
25
3dB Beam width Horizontal
Directional Antenna:65° /90° /105° /120°
Omni Antenna:360°
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 26/50
26
3dB Beam width Vertical
Directional Antenna Omni Antenna
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 27/50
27
Down Tilt
Mechanical Downtilt
Settled Electrical Downtilt
Modified Electrical Downtilt
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 28/50
28
Down Tilt
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 29/50
29
Down Tilt
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 30/50
30
No Downtilt Electrical DowntiltMechanical
Downtilt
Down Tilt
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 31/50
31
Down Tilt
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 32/50
32
Front to Back Ratio
The ratio of front max beam to
back max beam
F/B = 10 log typically : 25dB(Front Power)
(Back Power)
Back Power Front Power
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 33/50
33
Elevation Upper Side lobes & Null Fill
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 34/50
34
Elevation Upper Side
lobes(dB)
Sidelobes
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 35/50
35
Null Fill
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 36/50
36
Permitted Power
The permitted power rangeof common antenna
25-1500 W
The permitted power of
BTS antenna should bebigger than 200 W
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 37/50
37
Third Order Inter modulation
IMD@2×43dBm
f 1, f 2, 2f 1-f 2, 2f 2-f 1
830MHz,835MHz,840MHz,845MHz
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 38/50
38
1000mW ( 1W) 1mW
10log(1000mW/1mW) = 30dB
Isolation
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 39/50
39
Syllabus¾ BTS Antenna System
Introduction
¾ Antenna Diversity
¾
Electrical properties
¾ Mechanical properties
¾ Antenna Development
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 40/50
Mechanical properties
Weight
Radome Material
Operation and Storage
Configuration Parameters
Mast
Light Protection
Dimensions
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 41/50
41
Dimensions
length×width×height
length:be related to vertical
beamwidth and gain
width: be related to horizontalbeamwidth
height:
be related to thetechnology of antenna
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 42/50
42
Weight
Having an Influence on
Transportation and Construction
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 43/50
43
Radome Material
PVC, ABS, fiberglass,etcSun-proof 、prevent frostbite,Fire-
retardant etc
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 44/50
44
Operation and Storage
Storage Temperature Range :
Operating Temperature Range:
Typical:-40°C — +70°C
Typical:-40°C — +70°C
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 45/50
45
Configuration Parameters
Flat Plate Area
Shipping Dimensions
Wind Load
length×width×height
Eg: 83N at 160 km/h
The smaller the betterConnector Type
7/16”DIN,N,SMA female
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 46/50
46
Mast
Mast diameter 45-90mm
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 47/50
47
Light Protection
DC Ground
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 48/50
48
Syllabus¾ BTS Antenna System
Introduction
¾ Antenna Diversity
¾ Electrical properties
¾ Mechanical properties
¾ Antenna Development
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 49/50
49
Antenna Development
Wide Frequency
Much Function
High Integration
Smart Antenna
7/29/2019 6.Antenna introduction(V0.1).pdf
http://slidepdf.com/reader/full/6antenna-introductionv01pdf 50/50
50