Antenna Basic

Basic Principles For base station Antenna psystems

Antenna TheoryAntenna Theory

By

Amir Miraj, Senior Engineer,

1

Base Station Antenna Technology E l tiEvolution

AntennaCore

Omni Directional

Vertical Polarization

DualPol®MIMO

DualPol®RET

Dual BandCapacity Improvement

DigitalBeam Former

SmartBeam®

Capacity”

Technology

Interference ReductionMIMO

with FrequencyMIMO

SDMACapacity

Load BalanceMIMO

AirInterfaces Dominate Application Significant Application Low Application

AMPS

GSM

CDMA

W-CDMA

WiMAX

TD-SCDMA

LTE

2

LTE

Dipole F0(MHz)

λ(Meters

λ(Inches(MHz) (Meters

)(Inches

)

30 10 0 393 6¼ λ

30 10.0 393.680 3.75 147.6

160 1 87 73 8160 1.87 73.8280 1.07 42.2460 0 65 25 7

F0 ¼ λ460 0.65 25.7800 0.38 14.8960 0.31 12.3

1700 0.18 6.95

3

2000 0.15 5.9

3D View Antenna Pattern

Source: COMSEARCH

4

Source: COMSEARCH

Understanding The Mysterious “dB”g y

dBd Signal strength relative to a dipole in empty space

dBi Signal strength relative to an isotropic radiator

dB Difference between two signal strengths

dBm Absolute signal strength relative to 1 milliwatt1 mWatt = 0 dBm Note: The

Logarithmic Scale1 Watt = 30 dBm20 Watts = 43 dBm

dBc Signal strength relative to a signal of known strength,

Logarithmic Scale10 * log10 (Power Ratio)

in this case: the carrier signalExample: –150 dBc = 150 dB below carrier signalIf two carriers are 20 Watt each = 43 dBm

5

–150 dBc = –107 dBm or ~0.02 pWatt or ~1 microvolt

Effect Of VSWRG d VSWR i l t f ffi i t tGood VSWR is only one component of an efficient antenna.

Return Transmis Power PowerVSWR Loss

(dB)sion

Loss (dB)Reflected

(%)Trans.

(%)1 00 0 00 0 0 100 01.00 ∞ 0.00 0.0 100.01.10 26.4 0.01 0.2 99.81 20 20 8 0 04 0 8 99 21.20 20.8 0.04 0.8 99.21.30 17.7 0.08 1.7 98.31.40 15.6 0.12 2.8 97.21.50 14.0 0.18 4.0 96.0

6

2.00 9.5 0.51 11.1 88.9

Shaping Antenna Patterns

Vertical arrangement of properly phased dipoles allows controlVertical arrangement of properly phased dipoles allows control

of radiation patterns at the horizon as well as above and below

the horizon. The more dipoles that are stacked vertically, the

flatter the vertical pattern is and the higher the antenna

coverage or ‘gain’ is in the general direction of the horizon.

7

aping Antenna Patterns (Continued)

• Stacking 4 dipoles vertically in line changes the pattern shape (squashes the doughnut) and

Aperture of Dipoles

Vertical Pattern

Horizontal Pattern

(squashes the doughnut) and increases the gain over single dipole.

• The peak of the horizontal or

Single Dipole

• The peak of the horizontal or vertical pattern measures the gain.

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

• General Stacking Rule

4 Dipoles Vertically Stacked

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.

8

Doubling the number of elements increases gain by 3 dB, and reduces vertical beamwidth by half.

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

Why is it useful?Gain can be associated with coverage distance and/or obstacle penetration (buildings, foliage, Ga ca be assoc ated t co e age d sta ce a d/o obstac e pe et at o (bu d gs, o age,etc).

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

Wh i A d d d?What is Andrew standard?Andrew conforms to the industry standard of +/–1 dB accuracy.

9

Gain References (dBd And dBi)

• An isotropic antenna is a single point in space d f Isotropic Pattern

Isotropic (dBi)Dipole (dBd)radiating in a perfect

sphere (not physically possible).

Isotropic Pattern

Dipole Pattern

Dipole (dBd)Gain

dBd

dBi

• A dipole antenna is one radiating element (physically possible).

• A gain antenna is two or more radiating elements phased together. 0 (dBd) = 2.14 (dBi)

3 (dBd) = 5.14 (dBi)

10

Principles Of Antenna GainDirectional Antennas Top ViewOmni Antenna Side View

0 dd B

Directional Antennas, Top ViewOmni Antenna, Side View

0 dd 60°

‐3 dB

+3 ddB180°

0 dd B60

‐3 dB

3 ddB

‐‐3 dB3 dB+3 dd B 30°

‐3 dB

+6 dd B90°

‐‐3 dB3 dB

+6 dd B15°

‐3 dB

+9 dd B45°

‐‐3 dB3 dB

+9 dd B

7.5°

‐3 dB

11

Theoretical Gain Of Antennas (dBd)

3 dB Horizontal Aperture(Influenced by Grounded Back “Plate”)

Typical Lengthof Antenna (ft )

.9λ)

(Influenced by Grounded Back “Plate”) of Antenna (ft.)

360°

180°

120°

105° 90° 60° 45° 33°

800/900 MHz

1800/1900

VerticalBeamwidt

h

diators

ly Spa

ced (0

90 60 45 33 MHz 0 h1 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°

# of Rad

Verticall

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.

513.5

15.5

16.5 18.1 6 3 10°

8 9 12 13 14 15 17 18 19.6 8 4 7.5°

12

8 9 12 13 14 15 17 18 19.6 8 4 7.5Could be horizontal radiator pairs for narrow horizontal apertures.

Antenna Gain

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

• Losses: ConductorDielectricImpedancePolarizationPolarization

• Measure using ‘Gain by Comparison’

13

Antenna Polarization• Vertical polarization

– Traditional land mobile use– Omni antennas– Omni antennas– Requires spatial separation for diversity– Still recommended in rural, low multipath environments

• Polarization diversity– Slant 45° (+ and –) is now popular– Requires only a single antenna for diversityq y g y

– Lower zoning impact

– Best performance in high and medium multipath i tenvironments

Measured data will be presented in the Systems Section

14

Various Radiator Designs

800/900 MHz 800/900 MHz 800/900 MHz 800/900 MHz/PCB DualPol®

/DualPol® MAR

(Microstrip Annular Ring)

800/900 MHz DualPol®

/Log PeriodicVertical Pol

1800/1900/UMTSDualPol®

Interleaved Dual Band, DualPol® and MAR

1800/1900/UMTS PCB DualPol®

1800/1900/UMTS Vertical Pol

15

Directed Dipole (Microstrip Annular Ring)

Antenna Basics . . . Cross Polarized Dipoles

Two +/– 45° Polarized Dipoles

Single Vertically Polarized Dipole

16

Feed Harness ConstructionFeed Harness ConstructionASP705KASP705

(Old Style)LBX-6513DS

(Old Style)

Center Feed(Hybrid)

Series Feed CorporateFeed( y )

17

Feed Harness Construction (Continued)

Series Feed Center Feed(Hybrid) Corporate Feed(Hybrid)

Advantages

Minimum feed lossesSi l f d t

Frequency independent main lobe direction

Frequency independent main beam directionSimple feed system lobe direction

Reasonably simple feed system

beam directionMore beam shaping ability, sidelobe system sidelobe suppression

Disadvant Not as versatile as corporate (less

Complex feed system

BEAMTILT

+1°

+2°

ages as corporate (less bandwidth, less beam shaping)

system

450 455 460 465 470 MHz–2°

–1°

0°

+1

ASP‐705

18

Feed Networks

• Coaxial cable

– Best isolation

– Constant impedance

– Constant phase

• Microstripline corporate feeds• Microstripline, corporate feeds

– Dielectric substrate

– Air substrate

19

Microstrip Feed Lines

• Dielectric substrate

– Uses printed circuit technology

– Power limitations

– Dielectric substrate causes loss (~1.0 dB/m at 2 GHz)

Ai b• Air substrate

– Metal strip spaced above a groundplane

– Minimal solder or welded jointsMinimal solder or welded joints

– Laser cut or punched

– Air substrate cause minimal loss (~0.1 dB/m at 2 GHz)

20

Air Microstrip Network

21

LBX‐3316‐VTM Using Hybrid Cable/Air Stripline

22

LBX‐3319‐VTM Using Hybrid Cable/Air Stripline

23

DB812 Omni AntennaV ti l P ttVertical Pattern

24

P tt Si l ti

932DG65T2E‐MPattern Simulation

25

Key Antenna Pattern Objectives

For sector antenna, the key pattern objective is to focus as much energy as possible into a desired sector with a desired radius while minimizing unwanted interference to/from all other sectors.

This requires:

• Optimized pattern shaping

• Pattern consistency over the rated frequency band

• Pattern consistency for polarization diversity models

• Downtilt consistency

26

Main Lobe

What is it?The main lobe is the radiation pattern lobe that contains the majority portion of radiated

35° Total35° TotalMain LobeMain Lobethat contains the majority portion of radiated

energy.

Why is it useful?Shaping of the pattern allows theShaping of the pattern allows the contained coverage necessary for interference‐limited system designs.

How is it measured?How is it measured?The main lobe is characterized using a number of the measurements which will follow.

What is Andrew standard?Andrew conforms to the industry standard.

27

H i t l A d V ti l

Half‐Power Beamwidth

What is it?The angular span between the half‐power (‐3

Horizontal And Vertical1/2 Power1/2 PowerBeamwidthBeamwidth

dB) points measured on the cut of the antenna’s main lobe radiation pattern.

Why is it useful?

30 30

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

How is it measured?It is measured using data collected from antenna range testing.


28

Front‐To‐Back RatioWhat is it?The ratio in dB of the maximum directivity of an antenna to its directivity in a specified rearward direction Note that on a dualrearward direction. Note that on a dual‐polarized antenna, it is the sum of co‐pol and cross‐pol patterns.

Why is it useful?yIt characterizes unwanted interference on the backside of the main lobe. The larger the number, the better!

How is it measured?It is measured using data collected from antenna range testing. F/B Ratio @ 180 degreesF/B Ratio @ 180 degreesantenna range testing.

What is Andrew standard?Each data sheet shows specific performance. In general, traditional dipole and patch elements will yield 23–28 dB while the Directed Dipole™ style elements will yield 35–40 dB.

F/B Ratio @ 180 degreesF/B Ratio @ 180 degrees0 dB – 25 dB = 25 dB0 dB – 25 dB = 25 dB

29

y p y y

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

Why is it useful?Sidelobe level or pattern shaping

Sidelobe LevelSidelobe Level(–20 dB)(–20 dB)

Sidelobe level or pattern shaping allows the minor lobe energy to be tailored to the antenna’s intended use. See Null Fill and Upper Sidelobe SuppressionSidelobe Suppression.

How is it measured?It is always measured with respect to theIt is always measured with respect to the main lobe in dB.


30

y

Null FillingWhat is it?Null filling is an array optimization techniquethat reduces the null between the lo er lobes in the ele ation planelower lobes in the elevation plane.

Why is it useful?For arrays with a narrow vertical beam‐width (less than 12°) null fillingwidth (less than 12 ), null filling significantly improves signal intensity in all coverage targets below the horizon.

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.1st lower null.

What is Andrew standard?Most Andrew arrays will have null fill of 20–30 dB without optimization. To qualify as null fill, we expect no less than 15 and typically 10–12 dB!

31

q y , p yp y

I t t F A t With N El ti B idth

Null FillingImportant For Antennas With Narrow Elevation Beamwidths

Null Filled to 16 dB Below Peak

‐40

‐20

0

el (d

Bm)

Transmit Power = 1 W

Base Station Antenna Height = 40 m

B St ti A t G i 16 dBd

100

‐80

‐60

Received

Lev Base Station Antenna Gain = 16 dBd

Elevation Beamwidth = 6.5°

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

Distance (km)

R

32

Upper Sidelobe Suppression

What is it?Upper sidelobe suppression (USLS) is an array optimization technique that reduces the undesirable

First UpperSidelobeSuppression

sidelobes above the main lobe.

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 mechanically downtilted.

How is it measured?USLS is the relative dB difference between the peak of the main beam peak of the fi t id l bfirst upper sidelobe.

What is Andrew standard?Most of Andrew’s arrays will have USLS of >15 dB without optimization. The goal of all new designs is to suppress the first upper sidelobe to unity gain or lower

33

designs is to suppress the first upper sidelobe to unity gain or lower.

Orthogonality

What is it?The ability of an antenna to discriminate between two waves whose polarization difference is 90

δ

two waves whose polarization difference is 90 degrees.

Why is it useful?Orthogonal arrays within a single antenna Decorrelation between the Green and Blue Linesallow for polarization diversity. (As opposed to spacial diversity.)

How is it measured?

δ = 0°, XPol = –∞ dBδ = 5°, XPol = –21 dBδ = 10°, XPol = –15 dBδ = 15° XPol = –11 dB

Decorrelation between the Green and Blue Lines

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

δ = 15 , XPol = 11 dBδ = 20°, XPol = –9 dBδ = 45°, XPol = –3 dBδ = 50°, XPol = –2.3 dBδ = 60° XPol = –1 2 dB


δ = 60 , XPol = 1.2 dBδ =70°, XPol = –0.54 dBδ =80°, XPol = –0.13 dBδ =90°, XPol = 0 dB

XPol = 20 log ( sin (δ))

34

XPol = 20 log ( sin (δ))

120°

Cross‐Pol Ratio (CPR)

-20

-15

-10

-5

0

120What 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

-40

-35

-30

-25

Typicalover the 3 dB beamwidth).

Why is it useful?It is a measure of the ability of a cross‐pol array to distinguish between orthogonal waves The better Co‐Polarization

0

120°

distinguish between orthogonal waves. The better the CPR, the better the performance of polarization diversity.

How is it measured?

Co‐Polarization

Cross‐Polarization (Source @ 90°)

-30

-25

-20

-15

-10

-5

Directed

It is measured using data collected from antenna range testing and compares the two plots in dB over the specified angular range. Note: in the rear hemisphere, cross‐pol becomes co‐pol and vice

-40

-35 Dipole™

What is Andrew standard?For traditional dipoles, the minimum is 10 dB; however, for the Directed Dipole™ style elements it increases to 15 dB min

versa.

35

Directed Dipole style elements, it increases to 15 dB min.

Horizontal Beam Tracking

What is it?It refers to the beam tracking between the two beams of a +/–45° polarization diversity antenna 120°120°

p yover a specified angular range.

Why is it useful?For optimum diversity performance, +45°–45°

A Athe beams should track as closely as possible.

How is it measured?I i d i d ll d

Array Array

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

What is Andrew standard?The Andrew beam tracking standard is +/–1 dB over the 3 dB horizontal beamwidth.

36

Horizontal

Beam Squint

SquintSquintθ/2

θ

HorizontalBoresiteWhat is it?

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

Wh i it f l? –3 dB +3 dBWhy 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 antennas if the two arrays do not have similar patterns.

How is it measured?How is it measured?It is measured using data collected from antenna range testing.

What is Andrew standard?What is Andrew standard?For the horizontal beam, squint shall be less than 10% of the 3 dB beamwidth. For the vertical beam, squint shall be less than 15% of the 3 dB beamwidth or 1 degree whichever is greatest

37

1 degree, whichever is greatest.

Sector Power Ratio (SPR)120°120°

What is it?SPR is a ratio expressed in percentage of the power outside the desired sector

120120

pto the power inside the desired sector created by an antenna’s pattern.

Why is it useful?It is a percentage that allows comparison of various antennas. The better the SPR, the better the interference performance of the system.

How is it measured?It is mathematically derived from the measured range data.

300

Desired

Undesired

What is Andrew standard?Andrew Directed Dipole™ style antennas have SPR’s typically less than 2 percent.

PUndesired

SPR (%) = X 100

PDesired

300

60Σ

60

300Σ

38

K A t P t T E i Cl l

Antenna–Based System Improvements

Standard 85° Panel Antenna932LG

Directed Dipole™ Roll off–7 dB –6 dB

Key Antenna Parameters To Examine Closely

Directed Dipoleat ‐/+ 60°

‐10 dBpoints

74° 83°

83°74°

–16 dB –12 dB

HorizontalAnt/AntIsolation

points

Next SectorAnt/AntIsolation–35 dB –18 dB

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

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

Isolation

Coneof Silence

39

Key Antenna Pattern Objectives

Azimuth Beam

• Beam tracking vs. frequencyLi i d b b d b db d d l

1 1 1Limited to sub‐bands on broadband models

• Squint

• Roll‐off past the 3 dB points

1 1 1

1 2 3

• Front‐to‐back ratio

• Cross‐pol beam tracking

Elevation Beam

1 1 2

1 1 1

Ratings:

1 = Always important

Elevation Beam

• Beam tracking vs. frequency

• Upper sidelobe suppression

1 2 3

1 2 32 = Sometimes important

3 = Seldom important

• Lower null fill

• Cross‐pol beam tracking

3 3 2

2 2 3

40

Key Antenna Pattern Objectives (Continued)

Downtilt

• Electrical vs. mechanical tilt 1 1 3• Absolute tilt

• Electrical tilt vs. frequency

• Effective gain on the horizon

2 2 3

1 2 3• Effective gain on the horizon

Gain

• Close to the theoretical value

1 2 3

2 1 1(directivity minus losses)

Note: Pattern shaping reduces gain. Ratings:

1 = Always important

2 = Sometimes important

3 = Seldom important

41

d i ( )

Advanced Antenna Technology

Adaptive Array (AA)

• Planar array • 4 6 and 8 column vertical pol designs• Planar array

• External digital signal processing (DSP) controls the antenna pattern

• A unique beam tracks each mobile

• 4, 6, and 8 column vertical pol designsfor WiMAX and TD‐SCDMA*

• Often calibration ports are used

A unique beam tracks each mobile

• Adaptive nulling of interfering signals

• Increased signal to interference ratio performance benefits

* Time Division Spatial Code Division Multiple Access

42

MIMO S


MIMO Systems

2 x 2 MIMO Spatial Multiplexing

• Multiple Input Multiple Output • A DualPol® RET for 2x2 MIMO, two p p p p(MIMO)

• External DSP extracts signal from interference

separated for 4x4 MIMO

• Spatial multiplexing works best in a multi‐path environment

• Capacity gains due to multiple antennas

• Space Time Block Coding is a diversity MIMO mode

43

S B ® A F il


SmartBeam® Antenna Family

• Most flexible and efficient antenna system in the industry

• Solution for the traffic peaks instead of raising the bar everywhere• Solution for the traffic peaks instead of raising the bar everywhere

• Full 3‐way remote optimization options- RET – Remote Electrical Tilt (e.g. 0–10°)

RAS Remote Azimuth Steering (+/ 30°)- RAS – Remote Azimuth Steering (+/– 30 )

- RAB – Remote Azimuth Beamwidth (from 35° to 105°)

• Redirect and widen the beam based on traffic requirements

• Balance the traffic per area with the capacity per sector• Balance the traffic per area with the capacity per sector

• Best utilization of radio capacity per sector

• Convenient and low‐cost optimization from a remote office

• Quick and immediate execution

• Scheduled and executed several times a day (e.g. business and residential plan)

44

S B ®


SmartBeam®

3‐Way Model

Azimuth patterns d t

35° 65°measured at 1710–2180 MHz with no radome.

90° 105°

45

S B ®


SmartBeam®

3‐Way Model

Elevation patterns d t

35° 65°measured at 1710–2180 MHz with no radome.

90° 105°

46

System Issues

• Choosing sector antennas

• Narrow beam antenna applications

• Polarization—vertical vs. slant 45°

• Downtilt—electrical vs. mechanical

• RET optimization

• Passive intermodulation (PIM)

• Return loss through coax• Return loss through coax

• Antenna isolation

• Pattern distortion

47

Choosing Sector Antennas

For 3 sector cell sites, what performance differences can be expected from the

use of antennas with different horizontal apertures?p

Criteria

• Area of service indifference between adjacent sectors• Area of service indifference between adjacent sectors (ping‐pong area)

• For comparison, use 6 dB differentials

• Antenna gain and overall sector coverage comparisons

48

120° H i t l O l P tt

3 x 120° Antennas

-5

0

120° Horizontal Overlay Pattern

-25

-20

-15

-10 Examples

Low Band

VPol

-40

-35

-30

25

DB874H120DB878H120

Low Band

4949°°

3 dB

49

90° H i t l O l P tt

3 x 90° Antennas

-5

0

90° Horizontal Overlay Pattern

Examples

-25

-20

-15

-10

DB854DG90 DB842H90

Low Band

XPol VPol

-40

-35

-30

-25DB856DG90 DB844H90DB858DG90 DB848H90LBX‐9012 LBV‐9012LBX‐9013

44°44°

High Band

DB932DG90 UMW‐9015DB950G85

5 dB

DB950G85HBX‐9016UMWD‐09014B UMWD‐09016

50

5 dB

65° H i t l O l P tt Examples

3 x 65° Antennas65° Horizontal Overlay Pattern Examples

CTSDG 06513 DB844H65

Low Band

XPol VPol

-5

0

CTSDG‐06513 DB844H65CTSDG‐06515 DB848H65CTSDG‐06516 LBV‐6513DB854DG65

-25

-20

-15

-10

DB856DG65DB858DG65LBX‐6513LBX‐6516-40

-35

-30

-25

19°19°

High Band

UMWD‐06513 PCS‐06509 UMWD 06516 HBV 6516

10 dB

UMWD‐06516 HBV‐6516 UMWD‐06517 HBV‐6517HBX‐6516HBX‐6517

51

Special Narrow Beam Applications

4‐Sector Site (45°)

6‐Sector Site (33°) RepeaterRoad

Rural Roadway

Narrow Donor, Wide Coverage Antennas

52

Test Drive Route

35

183

CELL SITE

N

53

Polarization Diversity Tests

DB854HV90

DB854DD90DB854DD90

Test A

1 2

DRIVE TESTS +45°/‐45° 0°/90°(Slant 45°) (H/V)

.

Test B

HANDHELD

MOBILE

1A 2A

1B 2B

A

B

( ) ( / )

54

Slant 45° / Hand‐Held In CarS Di it Sl t d +45°/ 45° TEST 1ATEST 1A

Test Set‐Up and Uplink Signal Strength Measurements‐40

EEAA BB

DB854DD90DB833 DB833

G

Space Diversity vs. Slanted +45°/–45°Bm

)

‐50

‐60

9dB9dB

7.5 ft.7.5 ft.

9dB9dB

RedRed BlueBlue

11dB11dB

GreenGreen

BlackBlack

tren

gth (dB

‐70

Signal St

‐80

‐90

moving awayfrom tower

moving towardstower

Vert L f

Vert Ri h

Slant Di

SlantDi

UplinkSi l S h

‐90

‐100moving crossface

55

Left Right Div DivSignal Strength

Slant 45° / Hand‐Held In CarS Di it Sl t d +45°/ 45°

Difference Between Strongest Uplink Signals

TEST 1ATEST 1A

16

Space Diversity vs. Slanted +45°/–45°

8

12

(dB)

0

4

Stren

gth (

Slant ±45°I

‐4

0

Signal Improvement

Difference Between Polarization Diversity and Space DiversityAverage Difference

‐8

56

Slant 45° / Mobile With Glass Mount

S Di it Sl t d +45°/ 45°Test Set‐Up and Uplink Signal Strength Measurements

‐40

EEAA BB

DB854DD90DB833 DB833

TEST 1BTEST 1B

Space Diversity vs. Slanted +45°/–45°Bm

) 11dB11dB

GreenGreen

BlackBlack‐50

9dB9dB

7.5 ft.7.5 ft.

9dB9dB

RedRed BlueBlue

TEST 1BTEST 1B

Strength (d

B

‐60

‐70

moving awayfrom tower

moving towards

Signal S ‐70

‐80

moving towardstower

Vert Vert Slant SlantUplinkSi l St th

‐90moving crossface

57

Left Right Div DivSignal Strength

Slant 45° / Mobile With Glass Mount

S Di it Sl t d +45°/ 45°

Difference Between Strongest Uplink Signals

TEST 1BTEST 1B

16

Space Diversity vs. Slanted +45°/–45°

8

12

(dB)

0

4

l Stren

gth (

‐4

0

Signal

Slant ±45°Degradation

Difference Between Polarization Diversity and Space DiversityAverage Difference

‐8

58

Average Difference

Rysavy Research

59

Future Technology Focus

• Figure 16 shows that HSDPA,1xEV‐DO, and 802.16e are all within 2‐3 dB of the Shannon bound

Shannon’s Law

5

6Shannon boundShannon bound with 3dB marginE V-DOof the Shannon bound,

indicating that from a link layer perspective, there is not much room for improvement ab

le ra

te (b

ps/H

z)

3

4

E V DO802.16HSD PA

Peter Rysavy of Rysavy Research, “Data Capabilities: GPRS to HSDPA and Beyond”, 3G Americas, September 2005

improvement.

• This figure demonstrates that the focus of future technology enhancements h ld b i i

achi

eva

0

1

2

should be on improving system performance aspects that improve and maximize the experienced SNRs in the

t i t d f

The focus of future technology enhancements should be on improving system performance aspects that improve and maximize the experienced SNRs in the system.Peter Rysavy of Rysavy Research, Data Capabilities: GPRS to HSDPA and Beyond, 3G Americas, September 2005

required SNR (dB)-15 -10 -5 00

5 10 15 20

system instead of investigating new air interfaces that attempt to improve the link layer

f

1Peter Rysavy of Rysavy Research, “Data Capabilities: GPRS to HSDPA and Beyond”, 3G Americas, September 2005

60

performance.

L C Ch l I t f /B tt C it A d Q lit

The ImpactLower Co‐Channel Interference/Better Capacity And Quality

In a three sector site, traditional antennas produce a high degree of imperfect power

t l t l

Traditional Flat Panels

control or sector overlap.

Imperfect sectorization presents opportunities for:

• Increased softer hand‐offs

65° 90°

• Interfering signals• Dropped calls• Reduced capacity

The rapid roll‐off of the lower lobes of the Andrew Directed Dipole™ antennas create larger, better defined ‘cones of silence’ behind the array

Andrew Directed Dipole™

65° 90°

behind the array.

• Much smaller softer hand‐off area• Dramatic call quality improvement• 5%–10% capacity enhancement

61

120° Sector Overlay IssuesOn the Capacity and Outage Probability of a CDMA Heirarchial Mobile System with Perfect/Imperfect Power Control and SectorizationBy: 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 on CDMA System CapacityBy: Chin‐Chun Lee et, al IEEE TRANSACTIONS ON

ntage of

ty loss 10

15

VEHICULAR TECHNOLOGY, VOL. 47, NO. 3, AUGUST 1998

Overlapping angle in degree

Percen

capa

cit

0 5 10 15

5

0

Qualitatively, excessive overlay also reduces capacity of TDMA and GSM systems.

Overlapping angle in degree

62

Hard, Soft, and Softer Handoffs

H d H d ff• Hard Handoff

– Used in time division multiplex systems

– Switches from one frequency to anotherSwitches from one frequency to another

– Often results in a ping‐pong switching effect

• Soft Handoff

– Used in code division multiplex systems

– Incorporates a rake receiver to combine signals from multiple cells

– Smoother communication without the clicks typical in hard handoffshandoffs

• Softer Handoff

– Similar to soft handoff except combines signals from

63

p gmultiple adjacent sectors

Soft and Softer Handoff ExamplesSoft and Softer Handoff Examples

SofterSofter Handoff Two‐Way Soft

HandoffHandoffThree‐Way Soft Handoff

64

Beam Downtilt

In urban areas, service and frequency utilization are frequently improved by

directing maximum radiation power at an area below the horizon.g p

This technique . . .

• Improves coverage of open areas close to the base station• 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.

65

Electrical/Mechanical Downtilt

• Mechanical downtilt lowers main beam, raises back lobe.

• Electrical downtilt lowers main beam and lowers back lobeElectrical 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!g

66

Electrical/Mechanical Downtilt (Continued)

Mechanical Electrical

67

DB5083 Downtilt Mounting Kit

DB5083 downtilt mounting kit is

constructed of heavy duty galvanized steel,

designed for pipe mounting

12” to 20” wide panel antennas.

• Correct bracket calibration assumes a plumb mounting pipe!

• Check antenna with a digital level.

68

Mechanical DowntiltPattern Analogy—Rotating A Disk

Mechanical tilt causes . . .

• Beam peak to tilt below horizon

• Back lobe to tilt above horizon

• At ± 90°, no tilt

69

Mechanical Downtilt Coverage

40

50

6070

8090100110

120

130

140 40

50

6070

8090100110

120

130

140

0

10

20

30150

160

170

180 0

10

20

30150

160

170

180

190

200

210 330

340

350 190

200

210 330

340

350

220

230

240250

260 270 280290

300

310

320 220

230

240250

260 270 280290

300

310

320

8°0° 10°6°4°Mechanical Tilt

Elevation Pattern Azimuth Pattern

70

Managing Beam Tilt• For the radiation pattern to show maximum gain in the direction of the horizon, each stacked dipole must be fed from the signal source in phase.

• Feeding vertically arranged dipoles out of phase will generate patterns that look up or g y g p f p g p plook down.

• The degree of beam tilt is a function of the phase shift of one dipole relative to the adjacent dipole.

Dipoles Fed In Phase Dipoles Fed Out of Phase

Generating Beam Tilt

p

Energy

p f

ExciterPhase

in

Exciter

71

P tt A l F i A C O t Of A Di k

Electrical DowntiltPattern Analogy—Forming A Cone Out Of A Disk

Electrical tilt causes . . .

• Beam peak to tilt below horizon

B k l b t tilt b l h i• Back lobe to tilt below horizon

• At ± 90°, tilt below horizon

• All the pattern tilts

Cone of the

All the pattern tilts

Cone of the Beam Peak Pattern

72

Electrical Downtilt Coverage

40

50

6070

8090100110

120

130

140 40

50

6070

8090100110

120

130

140

0

10

20

30150

160

170

180 0

10

20

30150

160

170

180

190

200

210 330

340

350 190

200

210 330

340

350

220

230

240250

260 270 280290

300

310

320

Ele ation Pattern

220

230

240250

260 270 280290

300

310

320

A im th Pattern

8°0° 10°6°4°Electrical Tilt

Elevation Pattern Azimuth Pattern

73

Mechanical Vs. Electrical Downtilt0 10

2030

40

50310

320

330340

350

60

70

80

90270

280

290

300

100

110

120

130230

240

250

260

130

140

150160

170180190200

210

220

230

Mechanical ElectricalMechanical Electrical

74

Effects of Blooming on Sector PerformanceM( )E( ) Tilt Angle Crossover

M0E0 & M0E7 ‐‐‐‐ 17° 10 dB

M7E7 ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ 25° 6 dB

M14E0 ‐‐‐‐‐‐‐‐‐‐‐‐‐‐ 29° 4 dB

75

Combined Electrical and Mechanical Tilt

LNX-6512 Blooming (Calc)M0E0 0%

4 Foot Antenna at 780 MHz

M11E0 32.3%

M9E4 34 4%

60%

70%

M0E0 0%M4E0 3.1%M7E0 9.2%M9E0 16.9%M11E0 32.3%M0E4 0%

M7E0 9.2%

M9E0 16.9%

M7E4 18.8% M7E8 36.7%

M9E4 34.4%

M5E8 18 5%

40%

50%

% o

f VB

W) M4E4 6.3%

M7E4 18.8%M9E4 34.4%M0E8 0%M4E8 12.3%

M4E0 3.1%M4E4 6.3%

M4E8 12.3%M4E10 15.4%

M5E10 24.6%

M2E15 16.7%

M3E15 39.4%

M5E8 18.5%

10%

20%

30%

M-ti

lt (% M5E8 18.5%

M7E8 36.7%M0E10 0%M4E10 15.4%M5E10 24.6%M0E15 0%

M0E0 0% M0E8 0%M0E10 0%

M0E4 0% M0E15 0%

M1E15 6.1%

0%0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

E-tilt (% of VBW)

M0E15 0%M1E15 6.1%M2E15 16.7%M3E15 39.4%10% Blooming20% Blooming

76

20% Blooming

Combined Electrical and Mechanical Tilt

LNX-6515 Blooming (Calc)

8 Foot Antenna at 780 MHz

M6E0 40.5% M6E2 78.1%

60%

70%

M0E0 0%M2E0 2.9%M4E0 13.1%

M4E0 13.1%M4E2 25.0%

M4E4 46.9%

30%

40%

50%

(% o

f VB

W) M6E0 40.5%

M8E0 97.3%M0E2 0.0%M2E2 6.3%M4E2 25.0%10% Blooming

M2E0 2.9%M2E2 6.3%

M2E4 10.4%

M1E8 15.6%

M2E8 57.8%

10%

20%

30%

M-ti

lt 10% BloomingM6E2 78.1%M0E4 0.0%M2E4 10.4%M4E4 46.9%M0E8 0.0%

M0E0 0% M0E4 0.0% M0E8 0.0%M0E2 0.0%0%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

E-tilt (% of VBW)

M1E8 15.6%M2E8 57.8%20% Blooming

77

Modified “Rules of Thumb” for 10% Blooming

To insure that the azimuth pattern of a typical antenna ‐ as viewed on the horizon ‐ does not bloom by more than 10%, never mechanically downtilt a given antenna more than the amount calculated by the equations below:amount calculated by the equations below:

65º HBW M‐tilt10% Bloom = (VBW – E‐tilt)/2.5

Other HBW antennas follow different rules:



78

O ti i ti

Remote Electrical Downtilt (RET)Optimization ATM200‐002

RET Device (Actuator)

Local PC

ATC200 LITE USBATC200‐LITE‐USBPortable Controller

L l PC

ANMS™

Local PC

Network Server

ATC300‐1000Rack Mount Controller

Remote Locations

79

Wh ?

Intermod Interference

R

F1

Tx Rx

F3

Where?

TxF1

RxF3F2

Receiver‐Produced

TxF1

RxF3F2

Transmitter‐Produced

TxF2

TxF2

DUP

F3

F1F2

RxF3

Tx1

F1

F3

Rx3

DUPTx1

Tx2

COMB RF Path‐Produced

3

Tx2

F2 Elsewhere

80

RF Path Produced

P d t F i T Si l IM

High BandProduct Frequencies, Two‐Signal IM

P d t P d t P d t

FIM = nF1 ± mF2Example: F1 = 1945 MHz; F2 = 1930 MHz

1 1 Second 1F1 + 1F2 38751F1 – 1F2 15

Product Product Productn m Order Formulae Frequencies (MHz)

1 2

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

1 2 Third 2F2 + 1F1 5805*2F 1F 1915*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 d diff d f ll i b d

81

*Odd‐order difference products fall in‐band.

Odd O d Diff P d t

Two‐Signal IMOdd‐Order Difference Products

Example: F1 = 1945 MHz; F2 = 1930 MHz

ΔF = F1 ‐ F2 = 15

F F

ΔF

F21930

F11945

2F1 – F22F2 – F1

dBc

5th

3F2 – 2F11900

F2 F1 3rd

2F1 F21960

5th

3F1 – 2F21975

3rd

2F2 F11915

ΔF ΔFdBm

2ΔF 2ΔF

Third Order: F1 + ΔF; F2 ‐ ΔFFifth Order: F1 + 2ΔF; F2 ‐ 2ΔFSeventh Order: F1 + 3ΔF; F2 ‐ 3ΔFHigher than the highest – lower than the lowest – none in‐between

82

Higher than the highest – lower than the lowest – none in‐between

11th 9th 7th 5th 3rd

PCS A Band Intermodulation11th1855

9th1870

7th1885

5th1900

3rd1915 1930 1945

Channel BandwidthBlock (MHz) FrequenciesC 30 1895–1910 1975–1990

FCC Broadband PCS Band Plan

C 30 1895–1910, 1975–1990C1 15 1902.5–1910, 1982.5–1990C2 15 1895–1902.5, 1975–1982.5C3 10 1895–1900, 1975–1980C4 10 1900–1905, 1980–1985C5 10 1905–1910, 1985–1990

Note: Some of the original C block licenses (originally 30 MHz each) were split into multiple licenses (C‐1 and C‐2: 15 MHz; C‐3, C‐4, and C‐5: 10 MHz).

83

C5 10 1905 1910, 1985 1990

3rd

PCS A & F Band Intermodulation1895 1935 1975

Channel BandwidthBlock (MHz) FrequenciesC 30 1895–1910 1975–1990

FCC Broadband PCS Band Plan

C 30 1895–1910, 1975–1990C1 15 1902.5–1910, 1982.5–1990C2 15 1895–1902.5, 1975–‐1982.5C3 10 1895–1900, 1975–1980C4 10 1900–1905, 1980–1985C5 10 1905–1910, 1985–1990

Note: Some of the original C block licenses (originally 30 MHz each) were split into multiple licenses (C‐1 and C‐2: 15 MHz; C‐3, C‐4, and C‐5: 10 MHz).

84

C5 10 1905 1910, 1985 1990

Causes Of IMD

• Ferromagnetic materials in the current path:Steel– Steel

– Nickel plating or underplating

C di i• Current disruption:– Loosely contacting surfaces

– Non‐conductive oxide layers between contact surfaces

85

System VSWR CalculatorSystem VSWR Calculator

Version 9.0

Frequency (MHz): 850.00 18-Mar-09

System Component Max. VSWR Return Loss (dB)

Cable Type / Component Loss (dB)

Cable Length

(m)

Cable Length (ft)

Ins Loss w/2 Conn

(dB)

% of Est. System

Reflection

Reflections at input

Antenna or Load 1 50 13 98 87 2% 0 1003

Component Used?

Antenna or Load 1.50 13.98 87.2% 0.10032 2 Jumper 1.05 32.26 2 1.83 6.00 0.00 0.0% 0.00002 2 Tower Mounted Amp 1.20 20.83 0.20 0.00 0.0% 0.00002 2 Jumper 1.09 27.32 2 1.83 6.00 0.00 0.0% 0.00002 2 Top Diplexer or Bias Tee 1.15 23.13 0.20 0.00 0.0% 0.00002 2 Jumper 1.09 27.32 2.00 1.83 6.00 0.00 0.0% 0.00002 2 Main Feed Line 1.07 29.42 8 200.00 656.17 0.00 0.0% 0.00002 2 Jumper 1.09 27.32 4 30.48 100.00 0.00 0.0% 0.00002 2 Bi T 1 15 23 13 0 10 11 00 36 09 0 00 0 0% 0 0000

LDF4-50A

VXL7-50 No

No

No

No

No

No

N

No

2 2 Bias Tee 1.15 23.13 0.10 11.00 36.09 0.00 0.0% 0.00002 2 Jumper 1.09 27.32 2.00 1.83 6.00 0.00 0.0% 0.00002 2 Surge Suppressor 1.07 29.42 0.10 0.00 0.0% 0.00002 2 Jumper 1.09 27.32 3.00 1.83 6.00 0.00 0.0% 0.00002 2 Bottom Diplexer or Duplexer 1.20 20.83 0.10 0.00 0.0% 0.00001 1 Jumper 1.08 28.30 1.00 27.30 89.57 3.00 12.8% 0.0385

100.0%

Legacy Jumper / TL Cables Andrew CommScope1/2 i h S fl ibl C FSJ4 50B Estimated Conn Loss ( 2per cable) 0 028

No

No

No

No

YesYes

No

FSJ4-50B

1/2 inch Superflexible Copper FSJ4-50B Estimated Conn Loss ( 2per cable) 0.0281/2 inch Foam Copper LDF4-50A CR 540

1/2 inch Superflexible Aluminum SFX 500 Typical System Reflection: 0.10741/2 inch Foam Aluminum FXL 540 Typical System VSWR: 1.24

Typical System Return Loss (dB): 19.4Legacy Transmission Lines Andrew CommScope

7/8 inch Copper LDF5-50A CR 1070 Worst System Reflection: 0.13871 1/4 inch Copper LDF6-50 CR 1480 Worst System VSWR: 1.321 5/8 inch Copper LDF7-50A CR 1873 Worst System Return Loss (dB): 17.21 5/8 inch Copper LDF7 50A Worst System Return Loss (dB): 17.2

7/8 inch Very Flexible Copper VXL5-501 1/4 inch Very Flexible Copper VXL6-50 Total Insertion Loss (dB): 3.001 5/8 inch Very Flexible Copper VXL7-50

7/8 inch Virtual Air Copper AVA5-50 Return Loss to VSWR converter Feet to meters converterYes 1 5/8 inch Virtual Air Copper AVA7-50

7/8 inch Aluminum AL5-50 FXL 7801 1/4 inch Aluminum FXL 1480 17.00 1.33 100.00 30.481 5/8 inch Aluminum AL7-50 FXL 1873

metersReturn Loss (dB) VSWR Feet

86

No

Possible Cascaded VSWR ResultsPossible Cascaded VSWR ResultsPossible results (at a given frequency) when Antenna and TMA are interconnected withinterconnected with different electrical

length jumpers.If: L = 1.5:1 (14 dB RL Antenna)

S = 1.2:1 (20.8 dB RL TMA)

Then: X (max) = 1.8:1 (10.9 dB RL)

S (min) = 1.25:1 (19.1 dB RL)

Worst case seldom happens in real life, but

b th t it ibe aware that it is possible!

From http://www home agilent com/agilent/editorial jspx?cc=US&lc=eng&ckey=895674&nid=‐35131 0 00&id=895674

87

From http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=895674&nid= 35131.0.00&id=895674

Recommended Antenna/TMA Qualification Test

Antenna

6 foot LDF4‐50A

50 ohm load

6 foot LDF4‐50A

TMA TMAAdapter or jumper to bypass TMA

12 foot LDF4‐50A12 foot LDF4‐50A

TransmissionTransmission Line

20 foot

Transmission Line

20 foot FSJ4‐50

Antenna Return Loss Diagram

20 foot FSJ4‐50

TMA Return Loss Diagram

88

Attenuation Provided By VerticalSeparation Of Dipole Antennas

70

60

50

40

on in

dB

30

20

Isolati

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)

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. If values (1) the spacing is measured between the physical center of the tower antennas and it (2) one antenna is mounted directly above the other, with no horizontal offset collinear). No correction factor is required f th t i

89

for the antenna gains.

Attenuation Provided By HorizontalSeparation Of Dipole Antennas

80

70

60

50

on in

dB

40

30

Isolati

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)

20

Antenna Spacing in Feet (Meters)p g ( )

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).

90

Pattern Distortions

C d i ( lli ) b i i h h fConductive (metallic) obstruction in the path of transmit and/or receive antennas may distort antenna radiation patterns in a way that causes systems coverage problems and degradation of communications services.

A few basic precautions will prevent pattern distortions.

Additional information on metal obstructions can also be found online at: www.akpce.com/page2/page2.html

91

Sid Of B ildi M ti

Pattern DistortionsSide Of Building Mounting

BuildingBuilding

92

Ob t ti @ 10 dB P i t

90° Horizontal PatternObstruction @ –10 dB Point

340330

0 1020

3040320

350

-5

0

880 MHz

7

50

60

0290

300

310

-25

-20

-15

-10

0°

80

90

100260

270

280

-40

-35

-30

25

Antenna

–10 dB Point

BuildingCorner

100

110

120240

250

260

130

140150

160170180190

200210

220

230

93



-5

0340

330

0 1020

3040320

350

880 MHz

-25

-20

-15

-10 50

60

0290

300

310

0° –6 dB Point-40

-35

-30

25

80

90

100260

270

280

Antenna

BuildingCorner

100

110

120240

250

260

130

140150

160170180190

200210

220

230

94



-5

0340

330

0 1020

3040320

350

880 MHz

-25

-20

-15

-10 50

60

0290

300

310

0°–3 dB Point

Building-40

-35

-30

25

80

90

100260

270

280

Antenna

BuildingCorner

100

110

120240

250

260

130

140150

160170180190

200210

220

230

95

0 51λ Di Ob l @ 0°

90° Horizontal Pattern0.51λ Diameter Obstacle @ 0°

-5

0340

330

0 1020

3040320

350

880 MHz

-25

-20

-15

-10 50

60

0290

300

310

0°

12λ-40

-35

-30

25

80

90

100260

270

280

Antenna

12λ100

110

120240

250

260

130

140150

160170180190

200210

220

230

96

0 51λ Di t Ob t l @ 45°


-5

0340

330

0 1020

3040320

350

880 MHz

-25

-20

-15

-10

5

50

60

0290

300

310

45°-40

-35

-30

25

80

90

100260

270

280

Antenna

8λ100

110

120240

250

260

130

140150

160170180190

200210

220

230

97

0 51λ Di t Ob t l @ 60°


-5

0340

330

0 1020

3040320

350

880 MHz

-25

-20

-15

-10

5

50

60

0290

300

310

60°-40

-35

-30

25

80

90

100260

270

280

Antenna

6λ100

110

120240

250

260

130

140150

160170180190

200210

220

230

Additional information on metal obstructions can also be found online at www akpce com/page2/page2 html

98

www.akpce.com/page2/page2.html.

0 51λ Di t Ob t l @ 80°


-5

0340

330

0 1020

3040320

350

880 MHz

-25

-20

-15

-10

5

50

60

0290

300

310

-40

-35

-30

25

80

90

100260

270

280

Antenna

3λ80°100

110

120240

250

260

Additional information on metal obstructions can also be found online at www akpce com/page2/page2 html

130

140150

160170180190

200210

220

230

99

www.akpce.com/page2/page2.html.

A Th t N d T B F Of Ob t ti ( 0 51λ)

General RuleArea That Needs To Be Free Of Obstructions (> 0.51λ)

Maximum Gain

3 dB Point(45°)

> 12 WL

(45 )

6 dB Point(60°)( )

10 dB Point> 3 WLWL

Antenna90° horizontal (3 dB) beamwidth

(80– 90°)> 3 WL

100

Pattern Distortions

D

dθ

D

tan θ =

d = D x tan θ

dD

d x tan θtan 1° = 0.01745

for 0° < θ< 10° : tan θ = θ x tan 1°Note: tan 10° = 0 1763 10 x 0 01745 = 0 1745

101

Note: tan 10 = 0.1763 10 x 0.01745 = 0.1745

Gain Points Of A Typical Main Lobe

i lVertical BeamWidth= 2 x θ°θ°

θº

(–3 dB point)θ

Relative to Maximum GainRelative to Maximum Gain

–3 dB point θ° below boresite.–6 dB point 1.35 x θ° below boresite.–10 dB point 1.7x θ° below boresite.

102

Changes In Antenna Performance In The Presence Of:

Non‐Conductive Obstructions

FiberglassPanel

90°

Panel

°PCS A

ntennaaDim “A”

103

Performance Of 90° PCS AntennaBehind Camouflage (¼" Fiberglass)

120° FIBERGLASSPANEL

100°

110°

DIM “A”

90°

perture

80°

1/4 1/4 λλ 1/2 1/2 λλ 1 1 λλ 2 2 λλ11‐‐1/2 1/2 λλ3/4 3/4 λλizon

tal A

p

70°10 2 3 4 5 6 7 8 9 10 11 12

Distance of Camouflage (Inches) (Dim. A)

Hor

104

Performance Of 90° PCS Antenna

Behind Camouflage (¼" Fiberglass)

1 6

1.7

1.5

1.6FIBERGLASSPANEL

DIM “A”

1.4

st Case)

DIM “A”

1.2

1.3

WR (W

ors

1/4 1/4 λλ 1/2 1/2 λλ 1 1 λλ 2 2 λλ11‐‐1/2 1/2 λλ

W/Plain Façade W/Ribbed Façade Without Facade

1.210 2 3 4 5 6 7 8 9 10 11 12

Distance of Camouflage (Inches) (Dim. A)

VS

105

W/Plain Façade W/Ribbed Façade Without Facade

Distance From Fiberglass330°

300° 60°

30°0° 9090°°

330°

300° 60°

30°0° 102102°°

270°

240° 120°

90°

-35-40

-45

-50

-55

270°

240° 120°

90°

30-35-40

-45

-50

-55

210°180°

150°-20-25

-30

No Fiberglass 330°

300°

30°0°

6868°°

210°180°

150°-25

-30

-20

3" to Fiberglass300

270°

60°

90°

-40

-45

-50

240°

210°

180°150°

120°

-20

-25-30

-35

-15

1 5" to Fiberglass

106

1.5 to Fiberglass

Distance From Fiberglass330°

300°

60°

30°0° 112112°°330

°

300° 60°

30°0° 7777°°

270°

240°

120°

-25-30-35

-40

-45

-5090°270°

240°

120°

90°

-25

-30-35

-40

-45

-50

210° 180

°

150°

-20-15

6" to Fiberglass

210°180°

150°-20-15

4" to Fiberglass 330°

300° °

30°

0° 108108°°

300

270°

60°

90°

-40

-45

-50

240°

210° 180

°

150°

120°

-20

-25-30-35

-15

9" to Fiberglass

107

9 to Fiberglass

Antenna Basic

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Transcript of Antenna Basic