02 cdma antenna and feeder system

Customer Service Department of CDMA Division

Internal Use Only ▲

VIII.CDMA Antenna & Feeder System



CDMA Antenna and Feeder System

3.1 Antenna Introduction

3.2 BTS Antenna System

3.3 Antenna Technical Parameters

3.3.1 Electrical Properties

3.3.2 Mechanical Properties

3.4 Antenna Development


Internal Use Only ▲Antenna IntroductionAntenna Introduction

• Antenna is a structure or device used to

collect or radiate electromagnetic waves.

Transmission

radiates electromagnetic energy into space

Reception

collects electromagnetic energy from space



• Antennas are widely used in our society

– Mobile Communication

– Satellite Communication

– Wireless Radio

– Wireless Television

– Radar



• In two-way communication, the same antenna

can be used for transmission and reception

– the RF antenna System of the BTS

– GPS Antenna System

BSSB Antenna SystemBSSB Antenna System


Internal Use Only ▲BTS Antenna SystemBTS Antenna System

Antenna System Structure Antenna Types


Internal Use Only ▲Antenna System StructureAntenna System Structure

•

Lightningarrester

Antenna (6 sets;directional)

Jumper (1/2''; 6 PCS)

Lightning protectiongrounding clip

Main feeder (7/8''; 6 PCS)

BTScabinet

Lightning protectiongrounding clip

Cabling rackLightning protectiongrounding clip

Iron tower

Equipment room

Lightning arrester

Jumper (1/2''; 6 PCS)

the antenna feeder system comprises antenna, antenna jumper, main feeder, lightning arrester, cabinet-top jumper, grounding parts and others.


Internal Use Only ▲Antenna Technical ParametersAntenna Technical Parameters

Usually, antenna has two kinds of technical parameters:

Electrical Properties

Mechanical Properties



Frequency Range Impedance

VSWR polarization

Gain Beam width

Front to Back Ratio

Up Side Lobe suppression and Null Fill

Electrical PropertiesElectrical Properties



Wavelength

1/2 Wavelength

1/4 Wavelength

1/4 Wavelength

1/2 Wavelength

Dipole

DipolesDipoles

1800MHz ： 166mm

900MHz ： 333mm



one dipole Received Power ： 1mW

Dipole arrayReceived Power ： 4 mW

Gain = 10log(4mW/1mW) = 6dBd



10log(8mW/1mW) = 9dBd

Sector antennaReceived Power ： 8mW

Omnidirectional arrayReceived Power ： 4mW

(top view)

Antenna


Internal Use Only ▲Frequency RangeFrequency Range

• CDMA 800: 824-896MHz

• CDMA 1900: 1850-1990MHz



BANDWIDTH = 896 - 824 = 72MHz

Optimum 1/2 wavelengthfor dipole at 860MHz

at 896MHz

Antenna Dipole

at 824MHz


Internal Use Only ▲ImpedanceImpedance

• 50

Cable

50 ohms

Antenna 50 ohms



9.5 W80

ohms50 ohms

Forward: 10W

Reverse: 0.5W

Return Loss ： 10log(10/0.5) = 13dB

VSWR (Voltage Standing Wave Ratio)

VSWRVSWR



VSWR1.5

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

RL=-20lg


Internal Use Only ▲PolarizationPolarization

Vertical Horizontal

Vertical Polarization:

The electric field is vertical to the ground

Horizontal Polarization:

The electric field is parallel to the ground



+ 45degree slant - 45degree slant



V/H (Vertical/Horizontal) Slant (+/- 45°)

Dual Linear PolarizationDual Linear Polarization



Linear,vertical dual linear 45 slant



Definition

Ratio of antenna power density at a distant

point relative to that of an isotropic radiator

as the two input power values are the same.

Gain characterizes the ability of a antenna to

radiate and collect electromagnetic energy.

GainGain



)( 010

1inin PP

S

SG

G: Antenna gain

S1: Power density at a distant point relative to antenna

S0: Power density at the same point relative to isotropic

antenna

Pin1:Input power of the antenna

Pin0:Input power of the isotropic antenna

GainGain


Internal Use Only ▲GainGain

Unless otherwise specified, the gain usually refers to the direction of maximum radiation.



Antenna gain is usually expressed in dBi or dBd

dBi

Gain relative to an isotropic antenna when the re

ference antenna is an isotropic antenna.

dBd

Gain relative to a half-wave dipole when the refe

rence antenna is a half-wave dipole.

GainGain


Internal Use Only ▲dBd and dBidBd and dBi

half-wave dipole

isotropic radiator

So 0dBd = 2.15dBi

2.15dB



A directional antennaA directional antenna An Omni-directional antennaAn Omni-directional antenna

Directional & Omni-directional AntennaDirectional & Omni-directional Antenna



120° (eg) Peak

Peak - 10dB

Peak - 10dB

10dB Beamwidth

60° (eg) Peak

Peak - 3dB

Peak - 3dB

3dB Beamwidth

BeamwidthBeamwidth


Internal Use Only ▲Horizontal BeamwidthHorizontal Beamwidth

• Directional Antenna ： Omni Antenna ： 360°• 65°/90°/105°/120 °


Internal Use Only ▲Vertical Beam width Vertical Beam width

Directional Antenna ： Omni Antenna ：


Internal Use Only ▲Down TiltDown Tilt

Mechanical downtilt

Fixed electr. downtilt

Tunable electr. downtilt


Internal Use Only ▲Mechanical Down tiltMechanical Down tilt

Adjust antenna mechanically

to tilt lobe down


Internal Use Only ▲Front to Back RatioFront to Back Ratio

Main lobe max. value to back lobe max. value ratio

F/B = 10 log(forward Power/Reversed Power) typically ： 25dB

Reversed Power Forward Power


Internal Use Only ▲ Upper Side Lobes Suppression & Null FillUpper Side Lobes Suppression & Null Fill


Internal Use Only ▲Side lobesSide lobes

Upper Side Lobe Suppression (dB)



Null FillNull Fill


Internal Use Only ▲ Power CapacityPower Capacity

Continuous :25-1500watts

Typical: 250-500watts



1000mW ( 1W) 1mW

10log(1000mW/1mW) = 30dB

Antenna Port IsolationAntenna Port Isolation



For same frequency 、 dual frequency ， isolation of different port >30dB



Dimensions Weight Radome Material Color

Operating Temperature Range Storage Temperature Range

Mechanical PropertiesMechanical Properties


Internal Use Only ▲DimensionsDimensions

LengthLengthWidthWidthDepthDepth

Length Length ：： related with vertical beamwidthrelated with vertical beamwidth 、、 gaingain

WidthWidth ：： related with horizontal beamwidthrelated with horizontal beamwidth

DepthDepth ：： related with adoptive technologyrelated with adoptive technology


Internal Use Only ▲WeightWeight

Affect Transportation 、 construction


Internal Use Only ▲ Radome MaterialRadome Material

PVC, ABS, fiberglass

Sun Protection 、 Ice Protection ， Salt protection Burning Blocking ， Anti-aging etc.


Internal Use Only ▲Operating Temperature RangeOperating Temperature Range

TypicalTypical ：： -40°C — +70°C-40°C — +70°C


Internal Use Only ▲ Storage Temperature Range Storage Temperature Range

TypicalTypical ：： -40°C — +70°C-40°C — +70°C


Internal Use Only ▲Shipping DimensionsShipping Dimensions

LengthWidthDepth


Internal Use Only ▲MastMast

Mast diameter: 45-90mm


Internal Use Only ▲Lightning ProtectionLightning Protection

DC Grounded


Internal Use Only ▲Lightning rod Lightning rod

A grounded metal rod can prevent damage by conducting lightning to the ground；

It is placed on top of the structure


Internal Use Only ▲Lightning rod Lightning rod

The radio frequency antenna must be installed within the 45 protection angle for arrester；

Lightning arrester

45 protection angle

Lightning protection belt45 protection

angle

Antenna and outdoor unit


Internal Use Only ▲Antenna TypesAntenna Types

A directional antennaA directional antenna An Omni-directional antennaAn Omni-directional antenna


Internal Use Only ▲1/2 jumper1/2 jumper

½ jumper is used between cabinet-top and the main feeder cable , between the main feeder and antenna ;


Internal Use Only ▲1/2 jumper ’s properties1/2 jumper ’s properties

Specification ： ½ foamy medium cable; Maximum working frequency ： 2000MHz; Resistance ： 50; Wastage per 100m ： <7.5 dB; One-time bending radius ： 32mm;


Internal Use Only ▲The main feederThe main feeder

The minimum bending radius of the main feeder should not be less than 20 times the length of the radius of the main feeder

One-time bending, the minimum bending radius is 90mm. The minimum bending radius of repeated bends is 200 mm.


Internal Use Only ▲The main feeder’s propertiesThe main feeder’s properties

Specification ： 7/8 foamy medium cableMaximum working frequency ： 2000MHzResistance ：50Wastage per 100m ： <4.0 dB one-time bending radius ： 90mm


Internal Use Only ▲The three feeder clipThe three feeder clip

Installing the three-feeder clips every 1.5 meters along the iron tower or cabling rack; The maximum spacing

between the hangers is 1.65m.


Internal Use Only ▲The main feederThe main feeder

Feeder window

First bending with the bending radius larger

than 90 mm.

Cabling rack Feeder clip

OutdoorIndoorFeeder window

Outdoor

IndoorSecond bending with the

bending radius larger than 90 mm.

Cabling rack

Feeder clip


Internal Use Only ▲Lightning arrester’s propertiesLightning arrester’s properties

The feeder window is usually mounted on the wall outside the equipment room between the indoor and the outdoor cabling racks ; The size of the feeder cable window provided by ZTE is 400 mm 400 mm. It is a four-hole window and 12 pieces of feeder cables can pass through it. A 300 mm 300 mm hole should be drilled on the wall for the

installation of this feeder cable window.


Internal Use Only ▲Lightning arresterLightning arrester

For the wide-band lightning arrester that need not be grounded separately, you may directly connect it in serial to the place between the main feeder and the indoor cabinet top jumper. During the installation, the lightning arrester and indoor equipment as the cabling rack should be insulated.


Internal Use Only ▲Lightning arrester’s propertiesLightning arrester’s properties

Frequency ： 1850-1990MHzResistance ：50Echo wastage ： <-25dBThe maximum attacking electronic current ： 50

kAThe average manimum power ： 3kw


Internal Use Only ▲Lightning ArresterLightning Arrester

For the lightning arrester that need be grounded, a lightning arrester frame should be provided.


Internal Use Only ▲The installation of the lightning The installation of the lightning

arrester frame arrester frame

Feeder window

Antenna feederlightning arrester

Fixing plate of thelighting arrester

Lightningarrester frame

Jumper

Jumper

GPS Lightningarrester

Insulationsleeve

Grounding cable of the lightningarrester frame (to connect the

outdoor grounding bar)

Wall

Antennafeeder

GPS feeder


Internal Use Only ▲Connector between two accessoriesConnector between two accessories

Feeder connector


Internal Use Only ▲'' cabinet-top jumper'''' cabinet-top jumper''

cabinet-top jumpers are used between the lightning arrester connected to the main feeder and the rack ; it ’s properties are the same to the ½ antenna jumper ;


Internal Use Only ▲GPS Antenna Feeder System GPS Antenna Feeder System

BSC

GPS antenna

Coaxial cable

Lightning arrestorFixing caliper

Tube

Composition of the GPS Antenna Feeder System


Internal Use Only ▲GPS Antenna Feeder System GPS Antenna Feeder System

Capturing the clock for CDMAthrough the GPS signal receiver for use by the related units of the CDMA base station.

02 cdma antenna and feeder system

Education