3.5.3 Nokia Antennas

7/30/2019 3.5.3 Nokia Antennas

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1 © NOKIA Antennas_v04.ppt /22.05.2002 /PBe

Nokia Base Station Antennas

Please, refer to the notepages




Why Base Station Antennas?

The BTS antennas are- the sending element when

talking about the down linksignal (BTS to Mobile)

- the receiving element whentalking about the uplink signal(Mobile to BTS)

- an important part of thewhole communication chainand therefore only approvedantennas by Nokia should be

used

Downlink

Uplink

Base Station (BTS)

Mobile

Antenna System




Dipole (X-pol) Patch (X-pol)

Panel antenna technology

Dipole (V-pol)




V-pol versus X-pol design

Vertical polarized antenna

- one feeder connector per antenna

X polarized antenna

- dipoles slanted +/- 45° X shape

- two feeder connectors per antenna


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Horizontal beam width

• The comparision betweendifferent antenna horizontal beamwidths

65°

90°

105°120°

360° (Omni)

• The beam width for antennas aregiven as the “half -power beam

width“, the 3dB point

3dB



Vertical beam width and Gain

• to concentrate the radiated power into the area around the horizon,half wave dipoles are arrangedvertically and combined in phase

• with every doubling of the dipolesnumber

- the half power beam widthapproximately halves

- the gain increases by 3 dB in themain direction



• the network is divided into cells in ahoneycomb structure

• sector sites with 3 cells of differentfrequencies for a higher amount of subscribers

• smaller cells in high traffic areas likecities and city centers

• omni antennas for low traffic cells

• the topography, the repeatability of the frequencies and the antennalocations influence the networkplanning

Configuration of Cellular Networks



Down tilting the Antenna

• as a standard the vertical beam is

pointing to the horizon• downtilting of the pattern provides the

following benefits

- the majority of the radiated power isconcentrated within the sector

- the reduction of the power towards thehorizon avoids interference problemswith the next sector

• best results when fieldstrength in thehorizon is reduced by 6 dB

• selected downtilt angle depends on the

vertical half power beam width

Horizon

Horizon

6dB



Mechanical down tilt

Clamp set

Deformation of thehorizontal pattern

MechanicalDown tilt kit

• No “real“ maximum tilt angle

• Mechanical down tilt causes deformation in thehorizontal pattern

• For a complete installation also clamps or aclamp set is required

Clamp




Adjustable Electrical Down Tilt

• The Adjustable EDT antennas can be adjusted manually or remotely

• Phase shifters provides variable phase distribution which in turn keeps the

pattern shape constant

• Maximum Adjustable EDT range approx. 0-14° (normally 0-8°)

• For a higher downtilt angle a combination of the Mechanical DT and the Adjustable EDT is recommended

Horizontal pattern

remains constant

Remote useManual use




Adjustable Electrical Down Tilt Design

• Phase shifters for each dipole group provides variable phase distributions

• For sidelobe control the dipole groups are fed with different power • The phase shifter design is based on capacitive coupling, to avoid IM-

products

phase shifter

power splitter

example of a phase shifter




Dual Band Antenna

• separate radiation elements for 900MHz and 1800MHz

• 1800MHz dipoles interlocked betweenthe 900MHz dipoles

• vertical dipole spacing one wave length higher number of 1800MHz dipoles higher gain

• two feeder connectors per frequencyband 4 connectors per antenna

Th b fit i D l d T i l B d




The benefit using Dual and Triple Bandantennas

Instead of mounting three or two

antennas, only one antenna isrequired, per sector




BTS Antennas in the Nokia portfolio

• Antennas for the following cellular systems• UMTS / WCDMA• GSM and GSM EDGE• Tetra (a limited selection)

• Main types available are 33/45°, 65° & 88/90° Panelantennas with adjustable electrical down tilt and Omniantennas

• All main types with a selection of 2-4 different gainversions

• Antennas for Single, Dual, Wide or Triple Band use

• Smart Radio Concept (SRC) antennas




TX/RX antennafor the used frequency band

UMTS: 1920-2170MHzGSM 1900: 1850-1990MHzGSM 1800: 1710-1880MHz

GSM 900: 890-960MHzGSM 800: 824-894MHz

•2 RF feeders/sector

• RX diversity used

BTS

Antenna Line for 1 Sector, Single Band




TX/RX antennafor GSM1800/GSM1900/UMTS

(1710-2170MHz)•2 RF feeders/sector • no need for diplexersat the antenna end dueto wide/broad band elements

• RX diversity used

GSM1800

UMTS

Diplexer Diplexer

Antenna Line for 1 Sector, Wide Band




GSM

900

TX/RX antenna

for GSM900/1800or for GSM900/WideBand

• 4 RF feeders/sector • RX diversity used

GSM

1800

GSM

900

GSM

1800

Diplexers

Diplexers

• With external diplexers• 2 RF feeders/sector • RX diversity used

Antenna Line for 1 Sector, Dual Band

A t Li f 1 S t D l B d




Bias-T with DC-block

GSM1800

UMTS

Diplexer

DC-blocks for multi-MHA use

MHA DC-feedsfrom BTS

1800 MHAs WCDMA MHAs

Diplexers

• With external diplexers

• 2 RF feeders/sector • Rx diversity used

TX/RX antenna

for two times Wide Band(1710-2170/1710-2170MHz)

The Nokia Smart Radio Conceptcan be used with this antenna, if all four ports are used for thesame frequency band

Antenna Line for 1 Sector, Dual Band(SRC)




GSM

900

• With external

triplexers• 2 RF feeders/sector • RX diversity used

GSM

1800

Triplexers

Triplexers

UMTSGSM

900

GSM

1800UMTS

• Without triplexers• 6 RF feeders/sector • RX diversity used

TX/RX antennafor 900/1800/UMTS

Antenna Line for 1 Sector, Triple Band




• Antenna tilt is controlled remotely fromwithin the NetAct Framework by the user

• In a later NetAct version, both antennacontrol and optimal tilt calculation can becarried out automatically by the Optimizer tool running within the Nokia NetActFramework, if required

O&M data

0º tilt

14º ti lt

NetAct

O&M dataO&M data

0º tilt

14º ti lt

0º ti lt

14º tilt

0º ti lt

14º tilt

NetAct

Nokia RealTilt with NetAct




Nokia RealTilt

Tilt

Adjuste

(RTA)

Antenna

Additional

control cable

Feeder lines

Splitter (RSA)

• Nokia RealTilt is a fullyintegrated solution whichenables the optimization of WCDMA networks by adjustingantenna tilt angle remotely fromthe network managementsystem, Nokia NetAct

O&M Center

BTS

Control Unit (RCU)




Integrated

Hidden

Painted

Antenna camouflage

Documents

3.5.3 Nokia Antennas