Antenna Concepts

125
www.Telecom-Cloud.net Harish Vadada

Transcript of Antenna Concepts

Page 1: Antenna Concepts

www.Telecom-Cloud.net

Harish Vadada

Page 2: Antenna Concepts

Brief History

Antenna Building Blocks

Antenna System

Antenna System Tests

Radiation

Antenna Performance

Pattern Evaluation

Cell Planning Considerations

Down Tilt

Break

Intermodulation Interference

ObstructionsAntenna Performance

Break

Antenna Construction

Antenna Concealment

New Concepts

Page 3: Antenna Concepts

Thales (600 BC): Observed sparks when silk rubbed on amber, natural stones attracted

Gilbert (1600 AD), Franklin (1750), Coulomb, Gauss, Volta (1800), Oersted (1819), Ampere (1820), Ohm, Faraday, (1819), Ampere (1820), Ohm, Faraday, Henry (1831), Maxwell (1873)

Page 4: Antenna Concepts

Heinrich Rudolph Hertz’s (1886) built first radio system:

Page 5: Antenna Concepts

Guglielmo Marconi:- Repeated Hertz’s experiments- Built first radio system to signal over

large distances: England to Newfoundland- Proved radio waves bend around earth- Proved radio waves bend around earth- Also applied technology to ships

Page 6: Antenna Concepts
Page 7: Antenna Concepts
Page 8: Antenna Concepts

FFFF0000 (MHz)(MHz)(MHz)(MHz) λλλλ (Meters)(Meters)(Meters)(Meters) λλλλ (Inches)(Inches)(Inches)(Inches)

30303030 10.010.010.010.0 393.6393.6393.6393.6

80808080 3.753.753.753.75 147.6147.6147.6147.6¼ ¼ ¼ ¼ λλλλ

Dipole

80808080 3.753.753.753.75 147.6147.6147.6147.6

160160160160 1.871.871.871.87 73.873.873.873.8

280280280280 1.071.071.071.07 42.242.242.242.2

460460460460 0.650.650.650.65 25.725.725.725.7

800800800800 0.380.380.380.38 14.814.814.814.8

960960960960 0.310.310.310.31 12.312.312.312.3

1700170017001700 0.180.180.180.18 6.956.956.956.95

2000200020002000 0.150.150.150.15 5.905.905.905.90

FFFF0000 ¼ ¼ ¼ ¼ λλλλ

¼ ¼ ¼ ¼ λλλλ

Page 9: Antenna Concepts
Page 10: Antenna Concepts
Page 11: Antenna Concepts

Dipoles and the Antenna

A single dipole has a “doughnut” shaped pattern

Need to “flatten” the “doughnut” to concentrate the signal to where it is wanted, at ground level

Page 12: Antenna Concepts

Understanding the Mysterious “dB”–––– A dB is 1/10A dB is 1/10A dB is 1/10A dB is 1/10thththth of a “Bel” (Named after Alexander Graham of a “Bel” (Named after Alexander Graham of a “Bel” (Named after Alexander Graham of a “Bel” (Named after Alexander Graham

Bell)Bell)Bell)Bell)

–––– A dB is measured on a logarithmic scaleA dB is measured on a logarithmic scaleA dB is measured on a logarithmic scaleA dB is measured on a logarithmic scale

–––– A dB or “Decibel” originally comes from quantifying signal A dB or “Decibel” originally comes from quantifying signal A dB or “Decibel” originally comes from quantifying signal A dB or “Decibel” originally comes from quantifying signal

strengths in terms strengths in terms strengths in terms strengths in terms of relative loudness as registered by the of relative loudness as registered by the of relative loudness as registered by the of relative loudness as registered by the

human earhuman earhuman earhuman ear

–––– dB in the RF world is the difference between two signal dB in the RF world is the difference between two signal dB in the RF world is the difference between two signal dB in the RF world is the difference between two signal

strengthsstrengthsstrengthsstrengths

Blah

blahblah bl ah

Page 13: Antenna Concepts

A single dipole A single dipole A single dipole A single dipole radiates with a radiates with a radiates with a radiates with a

An isotropic radiator An isotropic radiator An isotropic radiator An isotropic radiator radiates equally inradiates equally inradiates equally inradiates equally in

dBd and dBi

radiates with a radiates with a radiates with a radiates with a doughnut patterndoughnut patterndoughnut patterndoughnut pattern

radiates equally inradiates equally inradiates equally inradiates equally inALL directionsALL directionsALL directionsALL directions

The gain of an antenna compared The gain of an antenna compared The gain of an antenna compared The gain of an antenna compared to a dipole is in “dBd”to a dipole is in “dBd”to a dipole is in “dBd”to a dipole is in “dBd”

The gain of an antenna compared The gain of an antenna compared The gain of an antenna compared The gain of an antenna compared to an isotropic radiator is in “dBi”to an isotropic radiator is in “dBi”to an isotropic radiator is in “dBi”to an isotropic radiator is in “dBi”eg: 3dBd = 5.17dBieg: 3dBd = 5.17dBieg: 3dBd = 5.17dBieg: 3dBd = 5.17dBi

2.17dB2.17dB2.17dB2.17dB

The dipole is 2.17dB higher in gainThe dipole is 2.17dB higher in gainThe dipole is 2.17dB higher in gainThe dipole is 2.17dB higher in gain

Page 14: Antenna Concepts

“dBm”“dBm”“dBm”“dBm” –––– Absolute signal strength relative to 1 milliwattAbsolute signal strength relative to 1 milliwattAbsolute signal strength relative to 1 milliwattAbsolute signal strength relative to 1 milliwatt

1 mWatt1 mWatt1 mWatt1 mWatt ==== 0 dBm0 dBm0 dBm0 dBm

1 Watt1 Watt1 Watt1 Watt ==== +30 dBm+30 dBm+30 dBm+30 dBm

10 Watts10 Watts10 Watts10 Watts ==== +40 dBm+40 dBm+40 dBm+40 dBm

20 Watts20 Watts20 Watts20 Watts ==== +43 dBm+43 dBm+43 dBm+43 dBm

“dBm and dBc”

Note: TheNote: TheNote: TheNote: TheLogarithmic ScaleLogarithmic ScaleLogarithmic ScaleLogarithmic Scale10 x log10 x log10 x log10 x log10101010 (Power Ratio)(Power Ratio)(Power Ratio)(Power Ratio)

“dBc”“dBc”“dBc”“dBc” –––– Signal strength Signal strength Signal strength Signal strength relativerelativerelativerelative to a signal of known strength, in to a signal of known strength, in to a signal of known strength, in to a signal of known strength, in

this case: the this case: the this case: the this case: the carriercarriercarriercarrier signalsignalsignalsignal

How and why is dBc used with base station antenna specs?How and why is dBc used with base station antenna specs?How and why is dBc used with base station antenna specs?How and why is dBc used with base station antenna specs?

Pay attention Pay attention Pay attention Pay attention –––– Group quiz later!Group quiz later!Group quiz later!Group quiz later!

Page 15: Antenna Concepts

Basic Antenna System

• Antenna

• Jumper Cable

• Feeder Cable• Feeder Cable

• Surge Arrestor

• Jumper Cable

• Radio

Page 16: Antenna Concepts

Full System Sweep

• 3 different tests

• Return Loss• VSWR• Distance to Fault (DTF)

• Antenna

• Jumper

Cable

• Feeder

Cable

• Surge

Arrestor

• Jumper

• Distance to Fault (DTF)

Page 17: Antenna Concepts

Impedance

• These 3 tests measure the reflected voltages caused by change of impedance in a transmission line.

• Impedance is measured in ohms (Ω).

V = I x R

or V = I x Z

Examples:

• Wireless = 50Ω

• Old TV = 300Ω

• Cable TV = 75Ω

where Z is defined as impedance and is complex

Z = R + j X

R = resistance and X = reactance both measured in ohms

or V = I x Z

Page 18: Antenna Concepts

Impedance

Outer Outer Outer Outer ConductorConductorConductorConductor

Cover (Jacket)Cover (Jacket)Cover (Jacket)Cover (Jacket)

ddddDDDD

Inner Inner Inner Inner ConductorConductorConductorConductor

Dielectric Dielectric Dielectric Dielectric (Foam)(Foam)(Foam)(Foam)

History note:

•Older CATV coax had air dielectric utilizing plastic disc’s to support the center conductor.

Page 19: Antenna Concepts

AntennaAntennaAntennaAntenna

50 ohms50 ohms50 ohms50 ohms

Source Source Source Source ====50 ohms50 ohms50 ohms50 ohms

Cable Cable Cable Cable ====

Impedance

====50 ohms50 ohms50 ohms50 ohms

Match!

Page 20: Antenna Concepts

Return Loss

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

W

51Ω51Ω51Ω51Ω

Transmitted: 9.92WTransmitted: 9.92WTransmitted: 9.92WTransmitted: 9.92W

A typical system A typical system A typical system A typical system alwaysalwaysalwaysalways has some nominal has some nominal has some nominal has some nominal

impedance mismatch.impedance mismatch.impedance mismatch.impedance mismatch. Here the Return Loss is Here the Return Loss is Here the Return Loss is Here the Return Loss is

10 log (0.08 / 10) = 10 log (0.08 / 10) = 10 log (0.08 / 10) = 10 log (0.08 / 10) = ----21dB21dB21dB21dB

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

W

50505050ΩΩΩΩ PASS!PASS!PASS!PASS!

Page 21: Antenna Concepts

Return Loss

* Limit lines should be provided by system design engineers.

Page 22: Antenna Concepts

AntennaAntennaAntennaAntenna

50 ohms50 ohms50 ohms50 ohms

Source Source Source Source ====50 ohms50 ohms50 ohms50 ohms

Cable Cable Cable Cable ====50 ohms50 ohms50 ohms50 ohms50 ohms50 ohms50 ohms50 ohms

Page 23: Antenna Concepts

AntennaAntennaAntennaAntenna

50 ohms50 ohms50 ohms50 ohms

System Failures

95 ohms95 ohms95 ohms95 ohmsSource Source Source Source ====50 ohms50 ohms50 ohms50 ohms

Smashed!Smashed!Smashed!Smashed!

When an impedance mismatch occurs in an RF subsystem, an When an impedance mismatch occurs in an RF subsystem, an When an impedance mismatch occurs in an RF subsystem, an When an impedance mismatch occurs in an RF subsystem, an amount of RF energy is reflected back to the source. amount of RF energy is reflected back to the source. amount of RF energy is reflected back to the source. amount of RF energy is reflected back to the source.

Mismatch!

Page 24: Antenna Concepts

95Ω95Ω95Ω95ΩIn

cid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

System Failures

Transmitted: 5.9WTransmitted: 5.9WTransmitted: 5.9WTransmitted: 5.9W

When something is wrong, much more When something is wrong, much more When something is wrong, much more When something is wrong, much more

energy will reflect causing performance energy will reflect causing performance energy will reflect causing performance energy will reflect causing performance

failures.failures.failures.failures. Here the Return Loss is Here the Return Loss is Here the Return Loss is Here the Return Loss is

10 log (4.1 / 10) =10 log (4.1 / 10) =10 log (4.1 / 10) =10 log (4.1 / 10) = ----3.87dB3.87dB3.87dB3.87dB50505050ΩΩΩΩ

FAIL!FAIL!FAIL!FAIL!

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Page 25: Antenna Concepts

System Failures

Page 26: Antenna Concepts

System Failures

What is the “standard” torque spec of a 7/16 DIN?

A) 18 to 22 ft-lbs.

B) 50 to 55 ft-lbs. A

Mini Group Quiz!

“Positive Stop” Connector- up to 70 ft-lbs

B) 50 to 55 ft-lbs.

C) 122 to 127ft-lbs

A

RF components have some reflection but damaged components will cause RF components have some reflection but damaged components will cause RF components have some reflection but damaged components will cause RF components have some reflection but damaged components will cause larger reflections and in that case creates a system to fail.larger reflections and in that case creates a system to fail.larger reflections and in that case creates a system to fail.larger reflections and in that case creates a system to fail.

Page 27: Antenna Concepts

VSWR

51Ω51Ω51Ω51ΩIn

cid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

W

Transmitted: 9.92WTransmitted: 9.92WTransmitted: 9.92WTransmitted: 9.92W

Voltage Standing Wave Ratio (VSWR) is Voltage Standing Wave Ratio (VSWR) is Voltage Standing Wave Ratio (VSWR) is Voltage Standing Wave Ratio (VSWR) is

related to Return Loss. The difference is related to Return Loss. The difference is related to Return Loss. The difference is related to Return Loss. The difference is

that VSWR is read as a ratio instead of in that VSWR is read as a ratio instead of in that VSWR is read as a ratio instead of in that VSWR is read as a ratio instead of in

dB.dB.dB.dB. Here the VSWR is Here the VSWR is Here the VSWR is Here the VSWR is

VSWR = (1+(10^21/20)) / (1VSWR = (1+(10^21/20)) / (1VSWR = (1+(10^21/20)) / (1VSWR = (1+(10^21/20)) / (1----(10^21/20))(10^21/20))(10^21/20))(10^21/20))

OrOrOrOr

----21dB RL = 1.195:1 VSWR21dB RL = 1.195:1 VSWR21dB RL = 1.195:1 VSWR21dB RL = 1.195:1 VSWR

50505050ΩΩΩΩ

PASS!PASS!PASS!PASS!

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

WR

efl

ecte

d: 0

.08

W

Page 28: Antenna Concepts

VSWR

Page 29: Antenna Concepts

VSWR

95Ω95Ω95Ω95ΩIn

cid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Transmitted: 5.9WTransmitted: 5.9WTransmitted: 5.9WTransmitted: 5.9W

Here the VSWR is Here the VSWR is Here the VSWR is Here the VSWR is

VSWR = (1+(10^3.8/20)) / (1VSWR = (1+(10^3.8/20)) / (1VSWR = (1+(10^3.8/20)) / (1VSWR = (1+(10^3.8/20)) / (1----(10^3.8/20))(10^3.8/20))(10^3.8/20))(10^3.8/20))

or

-3.84 dB RL = 4.60:1 VSWR50505050ΩΩΩΩ

FAIL!FAIL!FAIL!FAIL!

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Incid

ent

: 1

0W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Refl

ecte

d:4

.1W

Page 30: Antenna Concepts

VSWR

Page 31: Antenna Concepts

DTF

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Fault

These tests work best when These tests work best when These tests work best when These tests work best when

used as a references. used as a references. used as a references. used as a references.

Test results may be swayed Test results may be swayed Test results may be swayed Test results may be swayed

by variables such as vector by variables such as vector by variables such as vector by variables such as vector

addition and subtraction of addition and subtraction of addition and subtraction of addition and subtraction of

phase, interfering signals phase, interfering signals phase, interfering signals phase, interfering signals

and cable lengths. and cable lengths. and cable lengths. and cable lengths.

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

Tra

vel ti

me(m

s)

and cable lengths. and cable lengths. and cable lengths. and cable lengths.

Consider matching current Consider matching current Consider matching current Consider matching current

test results to previously test results to previously test results to previously test results to previously

recorded tests and look for recorded tests and look for recorded tests and look for recorded tests and look for

changes.changes.changes.changes.

Page 32: Antenna Concepts

DTF

Page 33: Antenna Concepts

Effect of VSWR

VSWRVSWRVSWRVSWRReturnReturnReturnReturnLoss (dB)Loss (dB)Loss (dB)Loss (dB)

TransmissionTransmissionTransmissionTransmissionLoss (dB)Loss (dB)Loss (dB)Loss (dB)

PowerPowerPowerPowerReflected (%)Reflected (%)Reflected (%)Reflected (%)

PowerPowerPowerPowerTrans. (%)Trans. (%)Trans. (%)Trans. (%)

1.00 −∞ 0.00 0.0 100.0

Good VSWR is only one component of an efficient antenna system.

Note: 2 dB in Return Loss is much smaller than 2 dB of forward gain!

1.10

1.20

1.30

1.40

1.50

2.00

−26.4

−20.8

−17.7

−15.6

−14.0

−9.5

0.01

0.04

0.08

0.12

0.18

0.51

0.2

0.8

1.7

2.8

4.0

11.1

99.8

99.2

98.3

97.2

96.0

88.9

Page 34: Antenna Concepts

Source: Source: Source: Source: COMSEARCHCOMSEARCHCOMSEARCHCOMSEARCH

3D View Antenna Pattern

Page 35: Antenna Concepts

Shaping Antenna PatternsShaping Antenna PatternsShaping Antenna PatternsShaping Antenna Patterns

Vertical arrangement of properly phased dipoles allows Vertical arrangement of properly phased dipoles allows Vertical arrangement of properly phased dipoles allows Vertical arrangement of properly phased dipoles allows

control of radiation patterns at the horizon as well as control of radiation patterns at the horizon as well as control of radiation patterns at the horizon as well as control of radiation patterns at the horizon as well as

above and below the horizon. above and below the horizon. above and below the horizon. above and below the horizon.

The more dipoles are stacked vertically, the flatter the The more dipoles are stacked vertically, the flatter the The more dipoles are stacked vertically, the flatter the The more dipoles are stacked vertically, the flatter the

“beam” is and the higher the antenna coverage or “gain” in “beam” is and the higher the antenna coverage or “gain” in “beam” is and the higher the antenna coverage or “gain” in “beam” is and the higher the antenna coverage or “gain” in

the general direction of the horizon.the general direction of the horizon.the general direction of the horizon.the general direction of the horizon.

Page 36: Antenna Concepts

Shaping Antenna Patterns Shaping Antenna Patterns Shaping Antenna Patterns Shaping Antenna Patterns (cont . . .)(cont . . .)(cont . . .)(cont . . .)

Stacking 4 dipoles vertically in line changes the pattern shape (squashes the doughnut) and increases the gain over single dipole.

The peak of the horizontal or vertical

Aperture Aperture Aperture Aperture of Dipolesof Dipolesof Dipolesof Dipoles

Vertical Vertical Vertical Vertical PatternPatternPatternPattern

Horizontal Horizontal Horizontal Horizontal PatternPatternPatternPattern

Single DipoleSingle DipoleSingle DipoleSingle Dipole

horizontal or vertical pattern measures the gain.

The little lobes, illustrated in the lower section, are secondary minor lobes.

4 Dipoles 4 Dipoles 4 Dipoles 4 Dipoles Vertically Vertically Vertically Vertically StackedStackedStackedStackedGENERAL STACKING RULE:GENERAL STACKING RULE:GENERAL STACKING RULE:GENERAL STACKING RULE:

• Collinear elements (in-line vertically).

• Optimum spacing (for non-electrical tilt) is approximately 0.9λ.

• Doubling the number of elements increases gain by 3 dB, and reduces

vertical beamwidth by half.

Page 37: Antenna Concepts

What is it?What is it?What is it?What is it?

Antenna gain is a comparison of the power/field characteristics of a device under test (DUT) to a specified gain standard.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

Gain is directly associated with link budget: coverage distance and/or obstacle penetration (buildings, foliage, etc).

How is it measured?How is it measured?How is it measured?How is it measured?

It is measured using data collected from antenna range testing. The reference gain standard must always be specified.

Page 38: Antenna Concepts

Gain References (dBd and dBi) Gain References (dBd and dBi) Gain References (dBd and dBi) Gain References (dBd and dBi)

An isotropic antenna is a single point in space radiating in a perfect sphere (not physically possible)

A dipole antenna is

Isotropic (dBi)Isotropic (dBi)Isotropic (dBi)Isotropic (dBi)Dipole (dBd)Dipole (dBd)Dipole (dBd)Dipole (dBd)GainGainGainGain

Isotropic PatternIsotropic PatternIsotropic PatternIsotropic Pattern

Dipole PatternDipole PatternDipole PatternDipole Pattern

A dipole antenna is one radiating element (physically possible)

A gain antenna is two or more radiating elements phased together

0 (dBd) = 2.15 (dBi)0 (dBd) = 2.15 (dBi)0 (dBd) = 2.15 (dBi)0 (dBd) = 2.15 (dBi)

3 (dBd) = 5.15 (dBi)3 (dBd) = 5.15 (dBi)3 (dBd) = 5.15 (dBi)3 (dBd) = 5.15 (dBi)

Page 39: Antenna Concepts

Principles of Antenna GainPrinciples of Antenna GainPrinciples of Antenna GainPrinciples of Antenna GainDirectional AntennasDirectional AntennasDirectional AntennasDirectional AntennasDirectional AntennasDirectional AntennasDirectional AntennasDirectional AntennasTop ViewTop ViewTop ViewTop ViewTop ViewTop ViewTop ViewTop View

0 dBd0 dBd0 dBd0 dBd0 dBd0 dBd0 dBd0 dBd

+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

180180°°

Omni AntennaOmni AntennaOmni AntennaOmni AntennaOmni AntennaOmni AntennaOmni AntennaOmni AntennaSide ViewSide ViewSide ViewSide ViewSide ViewSide ViewSide ViewSide View

0 dBd0 dBd0 dBd0 dBd0 dBd0 dBd0 dBd0 dBd

+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd

6060°°

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

3030°°

+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd

+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

9090°°

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

4545°°

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd+3 dBd

+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd+6 dBd

+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd+9 dBd

3030°°--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

7.57.5°°

--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

1515°°--------3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB

Page 40: Antenna Concepts

Theoretical Gain of Antennas (dBd)Theoretical Gain of Antennas (dBd)Theoretical Gain of Antennas (dBd)Theoretical Gain of Antennas (dBd)

Half Power Azimuth Beam WidthHalf Power Azimuth Beam WidthHalf Power Azimuth Beam WidthHalf Power Azimuth Beam Width(Influenced by Grounded Back “Plate”)(Influenced by Grounded Back “Plate”)(Influenced by Grounded Back “Plate”)(Influenced by Grounded Back “Plate”)

Typical LengthTypical LengthTypical LengthTypical Lengthof Antenna (ft.)of Antenna (ft.)of Antenna (ft.)of Antenna (ft.)

vert

ically s

paced

(0

.9vert

ically s

paced

(0

.9vert

ically s

paced

(0

.9vert

ically s

paced

(0

.9λλ λλ )) ))

800/900 DCS 1800 VerticalMHzPCS 1900 Beamwidth360° 180° 120° 105° 90° 60° 45° 33°

1 0 3 4 5 6 8 9 10.5 1' 0.5' 60°

2 3 6 7 8 9 11 12 13.6 2' 1' 30°

# o

f R

ad

iato

rs#

of

Rad

iato

rs#

of

Rad

iato

rs#

of

Rad

iato

rsvert

ically s

paced

(0

.9vert

ically s

paced

(0

.9vert

ically s

paced

(0

.9vert

ically s

paced

(0

.9

3 4.5 7.5 8.5 9.5 10.5 12.5 13.5 15.1 3' 1.5' 20°

4 6 9 10 11 12 14 15 16.6 4' 2' 15°

6 7.5 10.5 11.5 12.5 13.5 15.5 16.5 18.1 6' 3' 10°

8 9 12 13 14 15 17 18 19.6 8' 4' 7.5°

Page 41: Antenna Concepts

Gain vs. LengthGain vs. LengthGain vs. LengthGain vs. Length

Gain

(dBi)

10

15

20

25

65° Az BW 90° Az BW 120° Az BW

Antenna Length (wavelengths)

Gain

(dBi)

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 150

5 G=10 log ( )2.2 π L We

λ2

Page 42: Antenna Concepts

Gain vs. BeamwidthsGain vs. BeamwidthsGain vs. BeamwidthsGain vs. Beamwidths

Gain

(dBi)

10

15

20

25

65° Az BW 90° Az BW 120° Az BW

Elevation Half Power Beamwidth (deg)

Gain

(dBi)

2 4 6 8 10 12 14 16 18 20 22 24 26 28 300

5 G=10 log ( )29000AzBW EIBW

Page 43: Antenna Concepts

Antenna GainAntenna GainAntenna GainAntenna Gain

Gain (dBi) = Directivity (dBi) – Losses (dB)

Losses: Conductor

Dielectric

Impedance

PolarizationPolarization

Measure Using ‘Gain by Comparison’

Page 44: Antenna Concepts

Electric and magnetic fields are interdependent => Electromagnetic wave

Time-changing electric field generates magnetic field, vice versa

An antenna’s polarization is a An antenna’s polarization is a characteristic of the EM wave, i.e. electric field’s orientation

If antenna and incoming EM wave are co-polarized => Max response from antenna

Page 45: Antenna Concepts

Various Radiator Designs

DipoleDipoleDipoleDipole 1800/1900/UMTS1800/1900/UMTS1800/1900/UMTS1800/1900/UMTSDirected Dipole™Directed Dipole™Directed Dipole™Directed Dipole™

Diversity (DualDiversity (DualDiversity (DualDiversity (Dual----Pol)Pol)Pol)Pol)Directed Dipole™Directed Dipole™Directed Dipole™Directed Dipole™

ElementsElementsElementsElements

PatchPatchPatchPatch 800/900 MHz800/900 MHz800/900 MHz800/900 MHzDirected Dipole™Directed Dipole™Directed Dipole™Directed Dipole™

MARMARMARMARMicrostrip Annular RingMicrostrip Annular RingMicrostrip Annular RingMicrostrip Annular Ring

Directed Dipole™Directed Dipole™Directed Dipole™Directed Dipole™ Directed Dipole™Directed Dipole™Directed Dipole™Directed Dipole™

Page 46: Antenna Concepts

Dipoles

Single DipoleSingle DipoleSingle DipoleSingle Dipole Crossed DipoleCrossed DipoleCrossed DipoleCrossed Dipole

Page 47: Antenna Concepts

Series FeedSeries FeedSeries FeedSeries Feed Center FeedCenter FeedCenter FeedCenter Feed(Hybrid)(Hybrid)(Hybrid)(Hybrid)

CorporateCorporateCorporateCorporateFeedFeedFeedFeed

Page 48: Antenna Concepts

Feed Harness Construction (cont . . .)

Advantages:Advantages:Advantages:Advantages:

Center FeedCenter FeedCenter FeedCenter Feed(Hybrid)(Hybrid)(Hybrid)(Hybrid)

Frequency Frequency Frequency Frequency independent independent independent independent main lobe main lobe main lobe main lobe directiondirectiondirectiondirection Reasonably Reasonably Reasonably Reasonably

Corporate FeedCorporate FeedCorporate FeedCorporate Feed

Frequency Frequency Frequency Frequency independent independent independent independent main beam main beam main beam main beam directiondirectiondirectiondirection More beam More beam More beam More beam

Series FeedSeries FeedSeries FeedSeries Feed

Minimal feed lossesMinimal feed lossesMinimal feed lossesMinimal feed losses

Simple feed systemSimple feed systemSimple feed systemSimple feed system

Disadvantages:Disadvantages:Disadvantages:Disadvantages:

directiondirectiondirectiondirection Reasonably Reasonably Reasonably Reasonably simple feed simple feed simple feed simple feed systemsystemsystemsystem

Not as Not as Not as Not as versatile as versatile as versatile as versatile as corporate corporate corporate corporate (less (less (less (less bandwidth, bandwidth, bandwidth, bandwidth, less beam less beam less beam less beam shaping)shaping)shaping)shaping)

directiondirectiondirectiondirection More beam More beam More beam More beam shaping shaping shaping shaping ability, side ability, side ability, side ability, side lobe lobe lobe lobe suppressionsuppressionsuppressionsuppression

Complex Complex Complex Complex feed systemfeed systemfeed systemfeed system

BEAMTILTBEAMTILTBEAMTILTBEAMTILT

450450450450 455455455455 460460460460 465465465465 470470470470 MHzMHzMHzMHz+2+2+2+2°°°°

+1+1+1+1°°°°

0000°°°°

+1+1+1+1°°°°

+2+2+2+2°°°°

ASPASPASPASP----705705705705

Page 49: Antenna Concepts

Feed NetworksFeed NetworksFeed NetworksFeed Networks

Cable

Microstripline, Corporate Feeds

– Dielectric Substrate

– Air Substrate– Air Substrate

T-Line Feed and Radiator

Page 50: Antenna Concepts

Microstrip Feed LinesMicrostrip Feed LinesMicrostrip Feed LinesMicrostrip Feed Lines

Dielectric Substrate

– uses ‘printed circuit’ technology

– power limitations

– dielectric substrate causes loss (1.0 dB/m)

Air Substrate

– metal strip spaced above a groundplane

– minimal solder or welded joints

– laser cut or punched

– air substrate cause minimal loss (0.5 dB/m)

Page 51: Antenna Concepts

Air Microstrip Network

Page 52: Antenna Concepts

Dielectric Substrate Microstrip

Page 53: Antenna Concepts

Stacking Dipoles

4 Dipoles

8 Dipoles

1 Dipole

2 Dipoles

Page 54: Antenna Concepts

Azimuth Omni AntennaVertical Pattern

Page 55: Antenna Concepts
Page 56: Antenna Concepts

What is it?What is it?What is it?What is it?

The main lobe is the radiation pattern lobe that contains the majority portion of radiated energy.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

Shaping of the pattern allows the contained coverage necessary for interference-

35° TotalMain Lobe

necessary for interference-limited system designs.

How is it measured?How is it measured?How is it measured?How is it measured?

The main lobe is characterized using a number of the measurements which will follow.

Page 57: Antenna Concepts

What is it?What is it?What is it?What is it?

The angular span between the half-power (-3 dB) points measured on the cut of the antenna’s main lobe radiation pattern.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

It allows system designers to choose the optimum characteristics for coverage vs.

1/2 PowerBeamwidth

characteristics for coverage vs. interference requirements.

How is it measured?How is it measured?How is it measured?How is it measured?

It is measured using data collected from antenna range testing.

Page 58: Antenna Concepts

What is it?What is it?What is it?What is it?

The ratio in dB of the maximum directivity of an antenna to its directivity in a specified rearward direction.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

It characterizes unwanted interference on the backside of the main lobe. The larger the the main lobe. The larger the number, the better!

How is it measured?How is it measured?How is it measured?How is it measured?

It is measured using data collected from antenna range testing.

F/B Ratio

0 dB - 25 dB = 25 dB

Page 59: Antenna Concepts

What is it?What is it?What is it?What is it?

Sidelobe level is a measure of a particular sidelobe or angular group of sidelobes with respect to the main lobe.Why is it useful?Why is it useful?Why is it useful?Why is it useful?

Sidelobe level or pattern shaping allows the minor lobe energy to be tailored to

Sidelobe Level

(-20 dB)

lobe energy to be tailored to the antenna’s intended use. See Null Fill and Upper Sidelobe Suppression.

How is it measured?How is it measured?How is it measured?How is it measured?

It is always measured with respect to the main lobe in dB.

Page 60: Antenna Concepts

What is it?What is it?What is it?What is it?

Null Filling is an array optimization techniquethat reduces the null between the lower lobes in the elevation plane.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

For arrays with a narrow vertical beam-width (less than 12°), null filling significantly improves signal intensity in all coverage targets below the main lobe.all coverage targets below the main lobe.

How is it measured?How is it measured?How is it measured?How is it measured?

Null fill is easiest explained as the relative dB difference between the peakof the main beam and the depth of the 1st lower null.

Page 61: Antenna Concepts

Important for antennas with narrow elevation beamwidths.

Null Filled to 16 dB Below Peak

0

Receiv

ed L

evel (d

Bm

)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1-100

-80

-60

-40

-20

0

Distance (km)

Receiv

ed L

evel (d

Bm

)

Transmit Power = 1 W

Base Station Antenna Height = 40 m

Base Station Antenna Gain = 18 dBi

Elevation Beamwidth = 6.5°

Page 62: Antenna Concepts

What is it?What is it?What is it?What is it?

Upper sidelobe suppression (USLS) is an array optimization technique that reduces the undesirable sidelobes above the main lobe.Why is it useful?Why is it useful?Why is it useful?Why is it useful?

For arrays with a narrow vertical beamwidth (less than 12°), USLS can significantly reduce interference due to multi-path or when the antenna is to multi-path or when the antenna is mechanically downtilted.

How is it measured?How is it measured?How is it measured?How is it measured?

USLS is the relative dB difference between the peak of the main beam peak of the first upper sidelobe.

Page 63: Antenna Concepts

What is it?What is it?What is it?What is it?

The ability of an antenna to discriminate between two EM waves whose polarization difference is 90 degrees.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

Orthogonal arrays within a single antenna allow for polarization diversity. (As opposed to spatial

δ

diversity. (As opposed to spatial diversity.)

How is it measured?How is it measured?How is it measured?How is it measured?

The difference between the co-polar pattern and the cross-polar pattern, usually measured in the boresite (the direction of the main signal).

δ = 0°, XPol = -∞ dBδ = 5°, XPol =-21 dBδ =10°, XPol =-15 dBδ =15°, XPol =-11 dBδ =20°, XPol = -9 dBδ =30°, XPol = -5 dBδ =40°, XPol =-1.5 dB

XPol = 20 log ( tan (XPol = 20 log ( tan (XPol = 20 log ( tan (XPol = 20 log ( tan (δδδδ))))))))

Page 64: Antenna Concepts

What is it?What is it?What is it?What is it?

CPR is a comparison of the co-pol vs. cross-pol pattern performance of a dual-polarized antenna generally over the sector of interest (alternatively over the 3 dB beamwidth).Why is it useful?Why is it useful?Why is it useful?Why is it useful?

It is a measure of the ability of a dual-pol array to distinguish between orthogonal EM waves. The better the CPR, the better the

-40

-35

-30

-25

-20

-15

-10

-5

0

120°

TYPICALTYPICALTYPICALTYPICAL

Co-PolarizatiCross-waves. The better the CPR, the better the

performance of polarization diversity.

How is it measured?How is it measured?How is it measured?How is it measured?

It is measured using data collected from antenna range testing and compares the two plots in dB over the specified angular range.

-40

-35

-30

-25

-20

-15

-10

-5

0

120°

LOGLOGLOGLOG

Polarization

Cross-Polarization (Source @ 90°)

Page 65: Antenna Concepts

What is it?What is it?What is it?What is it?

It refers to the beam tracking between the two beams of a +/-45° polarization diversity antenna over a specified angular range.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

For optimum diversity performance, the beams should track as closely as possible.

120°

+45°-45°Array Array

possible.

How is it measured?How is it measured?How is it measured?How is it measured?

It is measured using data collected from antenna range testing and compares the two plots in dB over the specified angular range.

Page 66: Antenna Concepts

What is it?What is it?What is it?What is it?

The amount of pointing error of a given beam referenced to mechanical boresite.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

The beam squint can affect the sector coverage if it is not at mechanical boresite. It can also affect the performance of the polarization diversity style

-3 dB +3 dB

Squintθ/2

θ

HorizontalBoresite

polarization diversity style antennas if the two arrays do not have similar patterns.

How is it measured?How is it measured?How is it measured?How is it measured?

It is measured using data collected from antenna range testing.

Page 67: Antenna Concepts

What is it?What is it?What is it?What is it?

SPR is a ratio expressed in percentage of the power outside the desired sector to the power inside the desired sector created by an antenna’s pattern.

Why is it useful?Why is it useful?Why is it useful?Why is it useful?

It is a percentage that allows comparison of various antennas. The

120°

comparison of various antennas. The better the SPR, the better the interference performance of the system.How is it measured?How is it measured?How is it measured?How is it measured?

It is mathematically derived from the measured range data.

PUndesired

SPR (%) =

X 100PDesired

300

60Σ

60

300Σ

DESIRED

UNDESIRED

Page 68: Antenna Concepts

“On the Capacity and Outage Probability of a CDMA Heirarchial Mobile System with Perfect/Imperfect Power Control and Sectorization”By: Jie ZHOU et, al IEICE TRANS FUNDAMENTALS, VOL.E82-A , NO.7 JULY 1999. . . From the numerical results, the user capacities are dramatically decreased as the imperfect power control increases and the overlap between the sectors (imperfect sectorization) increases . . .

“Effect of Soft and Softer Handoffs

120° Sector Overlay Issues

Per

cent

age

ofca

paci

ty lo

ss

overlapping angle in degree

“Effect of Soft and Softer Handoffs on CDMA System Capacity”By: Chin-Chun Lee et, al IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 47, NO. 3, AUGUST 1998Qualitatively, excessive overlay also reduces capacity of TDMA and GSM systems.

Page 69: Antenna Concepts

The Impact: Lower Co-Channel Interference/Better Capacity & Quality

In a three sector site, traditional In a three sector site, traditional In a three sector site, traditional In a three sector site, traditional antennas produce a high degree of antennas produce a high degree of antennas produce a high degree of antennas produce a high degree of imperfect power control or sector imperfect power control or sector imperfect power control or sector imperfect power control or sector overlap.overlap.overlap.overlap.

Imperfect sectorization presents Imperfect sectorization presents Imperfect sectorization presents Imperfect sectorization presents opportunities for:opportunities for:opportunities for:opportunities for:

Increased softer handIncreased softer handIncreased softer handIncreased softer hand----offsoffsoffsoffs

Interfering signalsInterfering signalsInterfering signalsInterfering signals

Dropped callsDropped callsDropped callsDropped calls

Traditional Flat PanelsTraditional Flat PanelsTraditional Flat PanelsTraditional Flat Panels

The rapid rollThe rapid rollThe rapid rollThe rapid roll----off of the lower lobes off of the lower lobes off of the lower lobes off of the lower lobes of the log periodic antennas create of the log periodic antennas create of the log periodic antennas create of the log periodic antennas create larger, better defined “cones larger, better defined “cones larger, better defined “cones larger, better defined “cones of silence” behind the array.of silence” behind the array.of silence” behind the array.of silence” behind the array.

Much smaller softer handMuch smaller softer handMuch smaller softer handMuch smaller softer hand----off areaoff areaoff areaoff area

Dramatic call quality improvementDramatic call quality improvementDramatic call quality improvementDramatic call quality improvement

5% 5% 5% 5% ---- 10 % capacity enhancement10 % capacity enhancement10 % capacity enhancement10 % capacity enhancement

Log Periodics (Example)Log Periodics (Example)Log Periodics (Example)Log Periodics (Example)

Dropped callsDropped callsDropped callsDropped calls

Reduced capacityReduced capacityReduced capacityReduced capacity65656565°°°° 90909090°°°°

65656565°°°° 90909090°°°°

Page 70: Antenna Concepts

Key antenna parameters to examine closely…

Antenna-Based System Improvements

Roll offat -/+ 60°

-10 dBpoints

-7dB -6dB

Standard 85° Panel AntennaLog Periodic

74° 83°

74747474°°°° 83838383°°°°

HorizontalAnt/AntIsolation

-16dB -12dB

120°Cone of Silence with >40dB Front-to-Back Ratio

60°Area of Poor Silence with >27dB Front-to-Back Ratio

Next SectorAnt/AntIsolation

-35dB -18dB

Coneof Silence

Page 71: Antenna Concepts

Azimuth Pattern Comparison: 1850 MHz, 2-Deg EDT

-10

0

Am

plitu

de (

dB)

-50

-40

-30

-20

-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180

Azimuth Angle (Degrees)

Am

plitu

de (

dB)

Page 72: Antenna Concepts

Choosing sector antennas

Downtilt – electrical vs. mechanical

RET optimization

Passive intermodulation (PIM) Passive intermodulation (PIM)

Return loss through coax

Pattern distortion, alignment, orientation

Antenna isolation

Page 73: Antenna Concepts

Choosing Sector Antennas

For 3 sector cell sites, what performance differences For 3 sector cell sites, what performance differences For 3 sector cell sites, what performance differences For 3 sector cell sites, what performance differences

can be expected from the use of antennas with can be expected from the use of antennas with can be expected from the use of antennas with can be expected from the use of antennas with

different horizontal apertures?different horizontal apertures?different horizontal apertures?different horizontal apertures?

Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:Criteria:

Area of service indifference between adjacent sectors (“ping-pong” area).

For comparison, use 6 dB differentials.

Antenna gain and overall sector coverage.

Page 74: Antenna Concepts

3 x 120° Antennas

120120°°Horizontal Horizontal Overlay Overlay PatternPattern3 dB3 dB3 dB3 dB3 dB3 dB3 dB3 dB5757575757575757°°°°°°°°

Page 75: Antenna Concepts

3 x 90° Antennas

4343434343434343°°°°°°°° 9090°°Horizontal Horizontal Overlay Overlay PatternPattern

5 dB5 dB5 dB5 dB5 dB5 dB5 dB5 dB

Page 76: Antenna Concepts

3 x 65° Antennas

2424242424242424°°°°°°°° 6565°°Horizontal Horizontal Overlay Overlay PatternPattern

6 dB6 dB6 dB6 dB6 dB6 dB6 dB6 dB

Page 77: Antenna Concepts

Beam Downtilt

In urban areas, service and frequency utilization are In urban areas, service and frequency utilization are In urban areas, service and frequency utilization are In urban areas, service and frequency utilization are

frequently improved by directing maximum radiation power frequently improved by directing maximum radiation power frequently improved by directing maximum radiation power frequently improved by directing maximum radiation power

at an area below the horizon.at an area below the horizon.at an area below the horizon.at an area below the horizon.

ThisThisThisThisThisThisThisThis Technique:Technique:Technique:Technique:Technique:Technique:Technique:Technique:

Improves coverage of open areas close to the base station.

Allows more effective penetration of nearby buildings, particular high-traffic lower levels and garages.

Permits the use of adjacent frequencies in the same general region.

Page 78: Antenna Concepts

Electrical/Mechanical Downtilt

Mechanical downtilt lowers main beam, raises back lobe.

Electrical downtilt lowers main beam and lowers back lobe.

A combination of equal electrical and mechanical downtilts lowers main beam and brings back lobe onto the horizon!

Page 79: Antenna Concepts

Electrical/Mechanical Downtilt

MechanicalMechanicalMechanicalMechanical ElectricalElectricalElectricalElectrical

Page 80: Antenna Concepts

Mechanical Downtilt Mounting Kit

Page 81: Antenna Concepts

Mechanical Downtilt

Mechanical Tilt Causes:

• Beam Peak to Tilt Below Horizon

• Back Lobe to Tilt Above

Pattern Analogy: Rotating a Disk

• Back Lobe to Tilt Above Horizon

• At ± 90° No Tilt

Page 82: Antenna Concepts

Mechanical Downtilt Coverage

0

10

20

30

40

50

6070

8090100110

120

130

140

150

160

170

180

190 350

0

10

20

30

40

50

6070

8090100110

120

130

140

150

160

170

180

190 350 190

200

210

220

230

240250

260 270 280290

300

310

320

330

340

350190

200

210

220

230

240250

260 270 280290

300

310

320

330

340

350

8°0° 10°6°4°Mechanical Tilt

Elevation Pattern Azimuth Pattern

Page 83: Antenna Concepts

Sample Antenna0° Mechanical Downtilt

8585858585858585°°°°°°°°8585858585858585°°°°°°°°

Page 84: Antenna Concepts

Sample Antenna7° Mechanical Downtilt

9393939393939393°°°°°°°°9393939393939393°°°°°°°°

Page 85: Antenna Concepts

Sample Antenna15° Mechanical Downtilt

123123123123123123123123°°°°°°°°123123123123123123123123°°°°°°°°

Page 86: Antenna Concepts

Sample Antenna20° Mechanical Downtilt

HorizontalHorizontalHorizontalHorizontal3 dB Bandwidth 3 dB Bandwidth 3 dB Bandwidth 3 dB Bandwidth UndefinedUndefinedUndefinedUndefined

Page 87: Antenna Concepts

Managing Beam Tilt

For the radiation pattern to show maximum gain in the For the radiation pattern to show maximum gain in the For the radiation pattern to show maximum gain in the For the radiation pattern to show maximum gain in the direction of the horizon, each stacked dipole must be fed from direction of the horizon, each stacked dipole must be fed from direction of the horizon, each stacked dipole must be fed from direction of the horizon, each stacked dipole must be fed from the signal source “in phase”. Feeding vertically arranged the signal source “in phase”. Feeding vertically arranged the signal source “in phase”. Feeding vertically arranged the signal source “in phase”. Feeding vertically arranged dipoles “out of phase” will generate patterns that “look up” or dipoles “out of phase” will generate patterns that “look up” or dipoles “out of phase” will generate patterns that “look up” or dipoles “out of phase” will generate patterns that “look up” or “look down”.“look down”.“look down”.“look down”.

The degree of beam tilt is a function of the phase shift of one The degree of beam tilt is a function of the phase shift of one The degree of beam tilt is a function of the phase shift of one The degree of beam tilt is a function of the phase shift of one dipole relative to the adjacent dipole and their physical spacing.dipole relative to the adjacent dipole and their physical spacing.dipole relative to the adjacent dipole and their physical spacing.dipole relative to the adjacent dipole and their physical spacing.

GGGGGGGGENERATINGENERATINGENERATINGENERATINGENERATINGENERATINGENERATINGENERATING Electrical BElectrical BElectrical BElectrical BElectrical BElectrical BElectrical BElectrical BEAMEAMEAMEAMEAMEAMEAMEAM TTTTTTTTILTILTILTILTILTILTILTILTGGGGGGGGENERATINGENERATINGENERATINGENERATINGENERATINGENERATINGENERATINGENERATING Electrical BElectrical BElectrical BElectrical BElectrical BElectrical BElectrical BElectrical BEAMEAMEAMEAMEAMEAMEAMEAM TTTTTTTTILTILTILTILTILTILTILTILT

Dipoles Fed w/ Uniform PhaseDipoles Fed w/ Uniform PhaseDipoles Fed w/ Uniform PhaseDipoles Fed w/ Uniform Phase Dipoles Fed w/ Sequential PhaseDipoles Fed w/ Sequential PhaseDipoles Fed w/ Sequential PhaseDipoles Fed w/ Sequential Phase

ExciterPhase

Energy

inininin

Exciter

¼¼¼¼λλλλ

Page 88: Antenna Concepts

Electrical Downtilt

Electrical Tilt Causes:

• Beam Peak to Tilt Below Horizon

• Back Lobe to Tilt Below

Pattern Analogy: Forming a Cone Out of a Disk

• Back Lobe to Tilt Below Horizon

• All portions of the Pattern Tilts

“Cone” of the Beam Peak Pattern

Page 89: Antenna Concepts

Electrical Downtilt Coverage

0

10

20

30

40

50

60

708090100

110

120

130

140

150

160

170

180 0

10

20

30

40

50

60

708090100

110

120

130

140

150

160

170

180

190

200

210

220

230

240

250260 270 280

290

300

310

320

330

340

350

8°0° 10°6°4°Electrical Tilt

190

200

210

220

230

240

250260 270 280

290

300

310

320

330

340

350

Elevation Pattern Azimuth Pattern

Page 90: Antenna Concepts

Mechanical vs. Electrical Downtilt

0 1020

30

40

50

60

70

80280

290

300

310

320

330

340350

90

100

110

120

130

140

150

160170180190

200

210

220

230

240

250

260

270

Page 91: Antenna Concepts

With Variable Electrical Downtilt (VED), With Variable Electrical Downtilt (VED), With Variable Electrical Downtilt (VED), With Variable Electrical Downtilt (VED), you can adjust anywhere in seconds.you can adjust anywhere in seconds.you can adjust anywhere in seconds.you can adjust anywhere in seconds.

Page 92: Antenna Concepts

Sample Antenna3° Electrical Downtilt

Page 93: Antenna Concepts

Sample Antenna 8° Electrical Downtilt

Page 94: Antenna Concepts

Sample Antenna Overlay Electrical Downtilt

33333333°°°°°°°°

66666666°°°°°°°°

88888888°°°°°°°°

Page 95: Antenna Concepts

Remote Electrical Downtilt (RET)Optimization

ANMSANMS

Future

ATC100 Series

ATC200 Series

Page 96: Antenna Concepts

Causes of Inter-Modulation Distortion

Ferromagnetic materials in the current path:

– Steel

– Nickel Plating or Underplating

Current Disruption: Current Disruption:

– Loosely Contacting Surfaces

– Non-Conductive Oxide Layers Between Contact Surfaces

Page 97: Antenna Concepts

“Intermod” InterferenceWhere?

F1

TxF1

TxF2

RxF3

RECEIVER-PRODUCED

F3

TxF1

TxF2

RxF3

TRANSMITTER-PRODUCED

F2

F1

Rx3

ANTENNA-PRODUCED

DUP

F2

Tx1

Tx2

COMB

F3

RxF3

ELSEWHERE

Tx1

Tx2

Page 98: Antenna Concepts

Remember dBc?

IMD – Inter-Modulation Distortion

PIM – Passive Inter-Modulation

“dBc” with antennas work like this

- 2 tones @ 20Watts = 43dBm

- Scan for 3rd order of those 2 carriers

- If 3rd order = -110dBm then that = -153dBc

110dBm + 43dBm = 153dBc

Page 99: Antenna Concepts

PCS A-BandProduct Frequencies, Two-Signal IMFIM = nF1 ± mF2

Example: F1 = 1945 MHz; F2 = 1930 MHz

1 1 Second 1F1 + 1F2 38751F1 – 1F2 15

2 1 Third 2F1 + 1F2 5820*2F1 – 1F2 1960

ProductProductProductProduct ProductProductProductProduct ProductProductProductProductnnnn mmmm OrderOrderOrderOrder FormulaeFormulaeFormulaeFormulae Frequencies (MHz)Frequencies (MHz)Frequencies (MHz)Frequencies (MHz)

*2F1 – 1F2 1960

1 2 Third 2F2 + 1F1 5805*2F2 – 1F1 1915

2 2 Fourth 2F1 + 2F2 77502F1 – 2F2 30

3 2 Fifth 3F1 + 2F2 9695*3F1 – 2F2 1975

2 3 Fifth 3F2 + 2F1 9680*3F2 – 2F1 1900

*Odd-order difference products fall in-band.

Page 100: Antenna Concepts

Two-Signal IMOdd-Order Difference Products

Example: F1 = 1945 MHz; F2 = 1930 MHz

∆F = F1 - F2 = 15

∆F

3F2 – 2F1

1900

F2

1930

F1

1945 2F1 – F2

1960

F1 + ∆F3F1 – 2F2

1975

2F2 – F1

1915

F2 – ∆F∆F ∆F

Third Order: F1 + ∆F; F2 - ∆F

Fifth Order: F1 + 2∆F; F2 - 2∆F

Seventh Order:: F1 + 3∆F; F2 - 3∆F

“Higher than the highest – lower than the lowest – none in-between”

5th

F2 – 2∆F

1900

F2 F1 3rd

5th

F1 + 2∆F

1975

3rd

2∆F 2∆F

Page 101: Antenna Concepts

PCS Duplexed IM

Own RxOwn RxOwn RxOwn RxAny RxAny RxAny RxAny RxTxTxTxTx RxRxRxRx BandBandBandBand BandBandBandBand IM EquationsIM EquationsIM EquationsIM Equations

BandBandBandBandFrequencyFrequencyFrequencyFrequencyFrequencyFrequencyFrequencyFrequencyIM OrderIM OrderIM OrderIM OrderIM OrderIM OrderIM OrderIM OrderOwn Rx BandOwn Rx BandOwn Rx BandOwn Rx Band Any Rx BandAny Rx BandAny Rx BandAny Rx BandAAAA 1930193019301930----1945194519451945 1850185018501850----1865186518651865 11th11th11th11th 5th5th5th5th =6*Tx(low)=6*Tx(low)=6*Tx(low)=6*Tx(low)----5*Tx(high)=18555*Tx(high)=18555*Tx(high)=18555*Tx(high)=1855 =3*Tx(low)=3*Tx(low)=3*Tx(low)=3*Tx(low)----

2*Tx(high)=19002*Tx(high)=19002*Tx(high)=19002*Tx(high)=1900

BBBB 1950195019501950----1965196519651965 1870187018701870----1885188518851885 11th11th11th11th 7th7th7th7th =6*Tx(low)=6*Tx(low)=6*Tx(low)=6*Tx(low)----5*Tx(high)=18755*Tx(high)=18755*Tx(high)=18755*Tx(high)=1875 =4*Tx(low)=4*Tx(low)=4*Tx(low)=4*Tx(low)----3*Tx(high)=19053*Tx(high)=19053*Tx(high)=19053*Tx(high)=1905

CCCC 1975197519751975----1990199019901990 1895189518951895----1910191019101910 11th11th11th11th 11th11th11th11th =6*Tx(low)=6*Tx(low)=6*Tx(low)=6*Tx(low)----5*Tx(high)=19005*Tx(high)=19005*Tx(high)=19005*Tx(high)=1900 =6*Tx(low)=6*Tx(low)=6*Tx(low)=6*Tx(low)----5*Tx(high)=19005*Tx(high)=19005*Tx(high)=19005*Tx(high)=1900

Page 102: Antenna Concepts

A Band IM

1850 1870 1890 1910 1930 1950 1970 1990

Unlicensed

20 MHz

C-3 C-3 C-4C-4 C-5 C-5

11th11th11th11th1851851851855555

9th9th9th9th1871871871870000

7th7th7th7th1881881881885555

5th5th5th5th1901901901900000

3rd3rd3rd3rd1911911911915555

1931931931930000

1941941941945555

1860 1880 1900 1920 1940 1960 1980

C-1 C-1C-2 C-2

ChannelChannelChannelChannel BandwidthBandwidthBandwidthBandwidthBlockBlockBlockBlock (MHz)(MHz)(MHz)(MHz) FrequenciesFrequenciesFrequenciesFrequencies

CCCC 30303030 1895189518951895----1910, 19751910, 19751910, 19751910, 1975----1990199019901990

C1C1C1C1 15151515 1902.51902.51902.51902.5----1910, 1982.51910, 1982.51910, 1982.51910, 1982.5----1990199019901990

C2C2C2C2 15151515 1895189518951895----1902190219021902----5, 19755, 19755, 19755, 1975----1982.51982.51982.51982.5

C3C3C3C3 10101010 1895189518951895----1900, 19751900, 19751900, 19751900, 1975----1980198019801980

C4C4C4C4 10101010 1900190019001900----1905, 19801905, 19801905, 19801905, 1980----1985198519851985

C5C5C5C5 10101010 1905190519051905----1910, 19851910, 19851910, 19851910, 1985----1990199019901990

Note: Some of the original C Block licenses (Originally 30 MHz each) were split into multiplelicenses (C-1 and C-2: 15 MHz; C-3, C-4, and C-5: 10MHz).

FCC Broadband PCS Band PlanFCC Broadband PCS Band PlanFCC Broadband PCS Band PlanFCC Broadband PCS Band Plan

Page 103: Antenna Concepts

A and F Band IM

1850 1870 1890 1910 1930 1950 1970 1990

Unlicensed

20 MHz

C-3 C-3 C-4C-4 C-5 C-5

3rd3rd3rd3rd1891891891895555

1931931931935555

1971971971975555

1860 1880 1900 1920 1940 1960 1980

C-1 C-1C-2 C-2

ChannelChannelChannelChannel BandwidthBandwidthBandwidthBandwidthBlockBlockBlockBlock (MHz)(MHz)(MHz)(MHz) FrequenciesFrequenciesFrequenciesFrequencies

CCCC 30303030 1895189518951895----1910, 19751910, 19751910, 19751910, 1975----1990199019901990

C1C1C1C1 15151515 1902.51902.51902.51902.5----1910, 1982.51910, 1982.51910, 1982.51910, 1982.5----1990199019901990

C2C2C2C2 15151515 1895189518951895----1902190219021902----5, 19755, 19755, 19755, 1975----1982.51982.51982.51982.5

C3C3C3C3 10101010 1895189518951895----1900, 19751900, 19751900, 19751900, 1975----1980198019801980

C4C4C4C4 10101010 1900190019001900----1905, 19801905, 19801905, 19801905, 1980----1985198519851985

C5C5C5C5 10101010 1905190519051905----1910, 19851910, 19851910, 19851910, 1985----1990199019901990

Note: Some of the original C Block licenses (Originally 30 MHz each) were split into multiplelicenses (C-1 and C-2: 15 MHz; C-3, C-4, and C-5: 10MHz).

FCC Broadband PCS Band PlanFCC Broadband PCS Band PlanFCC Broadband PCS Band PlanFCC Broadband PCS Band Plan

Page 104: Antenna Concepts

System VSWR CalculatorFrequency (MHz): 895.00

System Component

Max. VSWR

Return Loss (dB)

Cable TypeCable

Length (m)Cable

Length (ft)Insertion Loss (dB)

Reflections at input

Antenna 1.33 16.98 0.0983Top Jumper 1.07 29.42 2 1.22 4.00 0.08 0.0239

Main Feed Line 1.11 25.66 1 30.48 100.00 1.18 0.0484Surge Suppressor 1.07 29.42 0.20 0.0329

Bottom Jumper 1.07 29.42 2 1.83 6.00 0.13 0.03381.59

Jumper Cable Types: 0.1216FSJ4-50B 1.28

Estimated System Reflection: Estimated System VSWR:

LDF4-50A

LDF5-50A

LDF4-50A

FSJ4-50B 1.28LDF4-50A 18.3

Main Feedline Cable Types: 0.2372LDF5-50A 1.62LDF6-50 12.5LDF7-50AVXL5-50VXL6-50 1.59VXL7-50

Return Loss (dB) VSWR feet meters28.00 1.0829 4.00 1.22

Estimated System VSWR: Estimated System Return Loss (dB):

Return Loss to VSWR converter Feet to meters convert er

Maximum System Reflection: Maximum System VSWR:

Maximum System Return Loss (dB):

Total Insertion Loss (dB):

Page 105: Antenna Concepts

Antenna Pattern Distortions

Conductive (metallic) obstruction in the path Conductive (metallic) obstruction in the path Conductive (metallic) obstruction in the path Conductive (metallic) obstruction in the path of transmit and/or receive antennas may of transmit and/or receive antennas may of transmit and/or receive antennas may of transmit and/or receive antennas may distort antenna radiation patterns in a way distort antenna radiation patterns in a way distort antenna radiation patterns in a way distort antenna radiation patterns in a way that causes systems coverage problems and that causes systems coverage problems and that causes systems coverage problems and that causes systems coverage problems and degradation of communications services.degradation of communications services.degradation of communications services.degradation of communications services.degradation of communications services.degradation of communications services.degradation of communications services.degradation of communications services.

A few basic precautions will prevent pattern A few basic precautions will prevent pattern A few basic precautions will prevent pattern A few basic precautions will prevent pattern distortions.distortions.distortions.distortions.

Page 106: Antenna Concepts

105° Horizontal Pattern No Obstacle

880 MHz880 MHz880 MHz880 MHz300°

105105105105105105105105°°°°°°°°

330°

60°

30°

-5

0

+5

+10

+15

-10

AntennaAntennaAntennaAntenna

270°

240°

210°180°

150°

120°

90°

Page 107: Antenna Concepts

105° Horizontal Pattern Obstruction at -10 dB Point

330°

300° 60°

30°0°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

-10 dB PointBuildingBuildingBuildingBuilding

CornerCornerCornerCorner

Page 108: Antenna Concepts

105° Horizontal Pattern Obstruction at -6 dB Point

330°

300° 60°

30°0°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

0° -6 dB Point

BuildingBuildingBuildingBuildingCornerCornerCornerCorner

Page 109: Antenna Concepts

105° Horizontal Pattern Obstruction at -3 dB Point

330°

300° 60°

30°0°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

0°-3 dB Point

BuildingBuildingBuildingBuildingCornerCornerCornerCorner

Page 110: Antenna Concepts

90° Horizontal Pattern No Obstacle

880 MHz880 MHz880 MHz880 MHz

330°

300° 60°

30°0°

-5

0

+5

+10

+15

-10

AntennaAntennaAntennaAntenna

270°

240°

210°180°

150°

120°

90°

Page 111: Antenna Concepts

90° Horizontal Pattern 0.5 l Diameter Obstacle at 0°

330°

300° 60°

30°0°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

12λλλλ

Page 112: Antenna Concepts

90° Horizontal Pattern 0.5 l Diameter Obstacle at 45°

330°

300° 60°

30°0°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

8λ8λ8λ8λ

45°

Page 113: Antenna Concepts

90° Horizontal Pattern 0.5 l Diameter Obstacle at 60°

330°

300° 60°

30°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

6λ6λ6λ6λ60°

Page 114: Antenna Concepts

90° Horizontal Pattern 0.5 l Diameter Obstacle at 80°

330°

300° 60°

30°

880 MHz880 MHz880 MHz880 MHz

270°

240°

210°180°

150°

120°

90°

AntennaAntennaAntennaAntenna

3λ3λ3λ3λ80°

Page 115: Antenna Concepts

General Rule Area that needs to be free of obstructions (> 0.57 WL)Area that needs to be free of obstructions (> 0.57 WL)Area that needs to be free of obstructions (> 0.57 WL)Area that needs to be free of obstructions (> 0.57 WL)

Maximum Gain

3 dB Point(45°)

6 dB Point

> 12 WL

Antenna90° horizontal (3 dB) beamwidth

6 dB Point(60°)

10 dB Point(80° - 90°)

> 3 WLWLWLWLWL

Page 116: Antenna Concepts

70

60

50

40

30

Isola

tion in d

B

Attenuation Provided By VerticalSeparation of Dipole Antennas

1 2 3 5 10 20 30 50 100(0.3) (0.61) (0.91) (1.52) (3.05) (6.1) (9.14) (15.24)(30.48)

30

20

10

Antenna Spacing in Feet (Meters)The values indicated by these curves are approximate because of coupling which exists between the antenna and transmission line. Curves are based on the use of half-wave dipole antennas. The curves will also provide acceptable results for gain type antennas. Values are measured between the physical center of the tower antennas and the antennas are mounted directly above the other, with no horizontal offset (collinear). No correction factor is required for the antenna gains.

Isola

tion in d

B

Page 117: Antenna Concepts

80

70

60

50

40

Attenuation Provided By HorizontalSeparation of Dipole Antennas

Isola

tion in d

B

10 20 30 50 100 200 300 500 1000(3.05) (6.1) (9.14) (15.24) (30.48) (60.96) (91.44) (152.4)(304.8)

40

30

20

Antenna Spacing in Feet (Meters)

Curves are based on the use of half-wave dipole antennas. The curves will also provide acceptable results for gain type antennas if (1) the indicated isolation is reduced by the sum of the antenna gains and (2) the spacing between the gain antennas is at least 50 ft. (15.24 m) (approximately the far field).

Isola

tion in d

B

Page 118: Antenna Concepts

Pattern Distortions

a

tan tan tan tan aaaa ====

dddd ==== D D D D **** tan tan tan tan aaaa

tan 1tan 1tan 1tan 1°°°° ==== 0.017450.017450.017450.01745

Note: tan 10Note: tan 10Note: tan 10Note: tan 10°°°° = 0.1763 10 = 0.1763 10 = 0.1763 10 = 0.1763 10 **** 0.01745 = 0.01745 = 0.01745 = 0.01745 = 0.17450.17450.17450.1745

ddddDDDD

Page 119: Antenna Concepts

Base Station Antenna w/ 4 Deg EDT

-20

-10

0

Am

plitu

de (

dB)

-50

-40

-30

-180 -150 -120 -90 -60 -30 0 30 60 90 120 150 180

Elevation Angle (Degree)

Am

plitu

de (

dB)

Page 120: Antenna Concepts

Gain Points of a Typical Main Lobe(Relative to Maximum Gain)

Vertical Vertical Vertical Vertical BeamBeamBeamBeam

Width= 2 Width= 2 Width= 2 Width= 2 aaaa((((----3dB point)3dB point)3dB point)3dB point)

aaaa

aaaa

----3dB point 3dB point 3dB point 3dB point aaaa°°°° below bore sight.below bore sight.below bore sight.below bore sight.

----6dB point 1.35 6dB point 1.35 6dB point 1.35 6dB point 1.35 **** aaaa°°°° below bore sight.below bore sight.below bore sight.below bore sight.

----10 dB point 1.7 10 dB point 1.7 10 dB point 1.7 10 dB point 1.7 **** aaaa°°°° below bore sight.below bore sight.below bore sight.below bore sight.

((((----3dB point)3dB point)3dB point)3dB point)

Page 121: Antenna Concepts

Changes In Antenna PerformanceIn The Presence of:

Non-Conductive Obstructions, such as Screens

FIBERGLASSFIBERGLASSFIBERGLASSFIBERGLASSPANELPANELPANELPANEL

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

Cell S

ite A

nte

nna

DIM “A”DIM “A”DIM “A”DIM “A”

Page 122: Antenna Concepts

Performance of Sample PCS AntennaBehind Camouflage (¼" Fiberglass)

100100100100°°°°

110110110110°°°°

120120120120°°°°

Hor

izon

tal A

pert

ure

FIBERGLASSFIBERGLASSFIBERGLASSFIBERGLASS

PANELPANELPANELPANEL

DIM “A”DIM “A”DIM “A”DIM “A”C

ell S

ite A

nt.

Cell S

ite A

nt.

Cell S

ite A

nt.

Cell S

ite A

nt.

70707070°°°°

80808080°°°°

90909090°°°°

11110000 2222 3333 4444 5555 6666 7777 8888 9999 10101010 11111111 12121212

1/4 1/4 1/4 1/4 1/4 1/4 1/4 1/4 λλλλλλλλ 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 λλλλλλλλ 1 1 1 1 1 1 1 1 λλλλλλλλ 2 2 2 2 2 2 2 2 λλλλλλλλ11111111--------1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 λλλλλλλλ3/4 3/4 3/4 3/4 3/4 3/4 3/4 3/4 λλλλλλλλ

Distance of Camouflage (Inches) (Dim. A)

Hor

izon

tal A

pert

ure

Page 123: Antenna Concepts

1.51.51.51.5

1.61.61.61.6

1.71.71.71.7

VS

WR

(W

orst

Cas

e)

Performance of Sample PCS AntennaBehind Camouflage (¼" Fiberglass)

FIBERGLASSFIBERGLASSFIBERGLASSFIBERGLASS

PANELPANELPANELPANEL

DIM “A”DIM “A”DIM “A”DIM “A”

Cell S

ite A

nt.

Cell S

ite A

nt.

Cell S

ite A

nt.

Cell S

ite A

nt.

1.21.21.21.2

1.31.31.31.3

1.41.41.41.4

11110000 2222 3333 4444 5555 6666 7777 8888 9999 10101010 11111111 12121212Distance of Camouflage (Inches) (Dim. A)

VS

WR

(W

orst

Cas

e)

W/Plain Facade W/Ribbed Facade Without Facade

1/4 1/4 1/4 1/4 1/4 1/4 1/4 1/4 λλλλλλλλ 1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 λλλλλλλλ 1 1 1 1 1 1 1 1 λλλλλλλλ 2 2 2 2 2 2 2 2 λλλλλλλλ11111111--------1/2 1/2 1/2 1/2 1/2 1/2 1/2 1/2 λλλλλλλλ

Page 124: Antenna Concepts

Distance From Fiberglass

No FiberglassNo FiberglassNo FiberglassNo Fiberglass

330°

300°

270°

240°

210°

180°

150°

120°

60°

30°

90°

9090909090909090°°°°°°°°

-20

-25

-30

-35

-40

-45

-50

-55

3" to Fiberglass3" to Fiberglass3" to Fiberglass3" to Fiberglass

330°

300°

270°

240°

210°

180°

150°

120°

60°

30°

0° 102102102102102102102102°°°°°°°°

90°

-25

-30

-35

-40

-45

-50

-55

-20

330°

300°

270°

240°

210°

180°

150°

120°

60°

30°

0° 6868686868686868°°°°°°°°

90°

-20

-25

-30

-35

-40

-45

-50

-15

1.5" to Fiberglass1.5" to Fiberglass1.5" to Fiberglass1.5" to Fiberglass

Page 125: Antenna Concepts

Distance From Fiberglass

6" to Fiberglass6" to Fiberglass6" to Fiberglass6" to Fiberglass

330°

300°

270°

240°

210° 180

°

150°

120°

60°

30°

111111111111111122222222°°°°°°°°

-20

-25

-30

-35

-40

-45

-50

-15

90°

4" to Fiberglass4" to Fiberglass4" to Fiberglass4" to Fiberglass

330°

300°

270°

240°

210°

180°

150°

120°

60°

30°

0°7777777777777777°°°°°°°°

90°

-20

-25

-30

-35

-40

-45

-50

-15

9" to Fiberglass9" to Fiberglass9" to Fiberglass9" to Fiberglass

330°

300°

270°

240°

210° 180

°

150°

120°

60°

30°

0° 101010101010101088888888°°°°°°°°

90°

-20

-25

-30

-35

-40

-45

-50

-15