Antenna Mast Design

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Telecommunications Masts& Towers

By S.Thananjayan


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Contents

Introduction

Design Concept

Typical Tower Components

Existing Tower Mast Structures

Summary

Empire State Building

Willis Tower

CN Tower

Tokyo Sky Tree Petronas Twin Tower

Lotus Tower

Lotus & Petronas Mast Comparison


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Introduction

Towers can be classified into four categories which are

Monopole, Lattice(Self Standing), Guyed or

Stealth

Antenna Tower Masts are structures made of Steel

Hollow sections or Lattice Type placed on top of

skyscrapers which are used to fix the Telecommunication,TV broadcasting antennas(UHF or VHF) and Radio

broadcasting antennas


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Design ConceptsReferences: Eng. Vasantha Kumuthu; Communication Masts by Brian W.S

1. To design an antenna mast first we should identify the

requirements that is the place, number of broadcasters to be

placed, type of broadcasting and strength

2. Designing the transmission antennas according to the

requirements

3. Mast designer will design the antenna tower mastconsidering the parameters(Minimum Height, Section size

and shape required) from antenna designer and structural

loads :- Dead and Wind(Predominant)


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Design Concept : Flow

Location

Type of broadcasting i.e. TV orRadio

Type of Signal i.e. Analogue orDigital

Frequency & Capacity

Regulatory Body Decides the Frequency

Intended Application

Social issues

Environmental issues

Cost

Antenna Manufacturer will design the Antenna Geometry

i.e. Antenna Cross Section and the Antenna Height

Antenna Mast Designer will design the Mast including all

the requirements from the Antenna Manufacturer and

Loadings


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Cont..

Typical Drag Coefficients for regular geometries and

pressure distribution around a cylindrical body submerged into a fluid

Ideal Fluid

Real Fluid


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Cont..

In the actual situation, antenna carries many antenna panels.

Therefore the drag force of the wind increases. Further due

to the vortex shedding effect also wind load increases

For a rigorous analysis of the mast, it is needed to conduct an

wind tunnel test to calculate the more accurate wind load on

the structure. It is done using an scaled model


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Cont..

Typical antenna components


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Cont..

Typical Properties

Antenna Panels

Antenna Cables
http://c/Users/hp/Desktop/TR%20A%20I%20N%20I%20NG/Lotus%20Tower/Powerpoint%20Presentations/Antenna%20Panel.pdfhttp://c/Users/hp/Desktop/TR%20A%20I%20N%20I%20NG/Lotus%20Tower/Powerpoint%20Presentations/Telecom%20Cables.pdfhttp://c/Users/hp/Desktop/TR%20A%20I%20N%20I%20NG/Lotus%20Tower/Powerpoint%20Presentations/Telecom%20Cables.pdfhttp://c/Users/hp/Desktop/TR%20A%20I%20N%20I%20NG/Lotus%20Tower/Powerpoint%20Presentations/Antenna%20Panel.pdf


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Cont..

Antenna Panels


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Cont..

Antenna Cables


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Typical Tower Components


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Existing Tower Mast Structures

Empire State Building


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Willis Tower

TV and FMTransmission

antennas


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CN Tower

102 m Height steel mast of 260 mph wind resistance and 10 ton swingingcounterparts mounted on the antenna

Dynamic Peak of the antenna is 68m from the centre

Broadcasting facility : Television(VHF, UHF and Cable)

FM Radio

Microwave Users


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Tokyo Sky Tree

Lattice Steel Mast for Television

Broadcasting 139 m Height above 495 m

Elevation


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Tokyo Sky Tree Cont...


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Petronas Twin Tower


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Cont.

Impact damper against excessive

wind-induced vibration Galvanized anchor chain of 54 kg/m

and 7.3 m length suspended within

the rope of the mast

400 mm dia. s.s. pipe(12 mm thk.)

fixed to the mast to provide uniform

free travel of the damper


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Lotus Tower

Lotus Tower mast is composed of Concrete mastof 27.6 m height & Steel mast of 64.1 m height

having a penetration of 7.0 m into the Concrete

mast.


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Cont..

Lotus Tower Mast Sections


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Petronas Tower

3m

50mm x 250mm S.S

Plate

12mm S.S Plate

Section X-X

X X


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Lotus Tower


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Cont..

Petronas Tower


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Summary

Types of Antenna Towers Monopole, Lattice(Self Standing), Guyed or

Stealth

Types of cables used intelecommunications

Twisted pair cables, coaxial cable, and fiber

optic cable

Antenna Mast design includes parameterssuch as Number of channels, Strength,

Architectural and Structural


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References

Telecommunications Masts and Towers

By Brian W. Smith

Eng. Vasantha Kumuthu

Lotus Tower Project

The Structural Design of Tall Buildings

John Wiley & Sons, Ltd.


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hank You

Documents

Antenna Mast Design