Basic Principles For base station Antenna p systems
Antenna Theory Antenna Theory
By Amir Miraj, Senior Engineer,
1
Base Station Antenna Technology E l ti Evolution Antenna Core Technology Omni Vertical DualPol® Directional Polarization MIMO
Air Interfaces
Dominate Application
DualPol® RET Interference Reduction MIMO Significant Application
Dual Band Capacity Improvement with Frequency MIMO
Digital Beam Former SDMA Capacity
SmartBeam® Capacity” Load Balance MIMO
Low Application
AMPS GSM CDMA W-CDMA WiMAX TD-SCDMA LTE
2
Dipole
F0 λ λ (MHz) (Meters (Inches ) ) ¼ λ
F0
¼ λ
30
10 0 10.0
393 6 393.6
80
3.75
147.6
160
1 87 1.87
73 8 73.8
280
1.07
42.2
460
0 65 0.65
25 7 25.7
800
0.38
14.8
960
0.31
12.3
1700
0.18
6.95
2000
0.15
5.9 3
3D View Antenna Pattern
Source: COMSEARCH Source: COMSEARCH
4
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 milliwatt Note: The 1 mWatt = 0 dBm Logarithmic Scale Logarithmic Scale 1 Watt = 30 dBm 10 * log10 (Power Ratio) 20 Watts = 43 dBm
dBc
Signal strength relative to a signal of known strength, in this case: the carrier signal Example: –150 dBc = 150 dB below carrier signal If two carriers are 20 Watt each = 43 dBm –150 dBc = –107 dBm or ~0.02 pWatt or ~1 microvolt 5
Effect Of VSWR G d VSWR i Good VSWR is only one component of an efficient antenna. l t f ffi i t t
Return Transmis Power Power VSWR Loss sion Reflected Trans. (dB) Loss (dB) (%) (%) 1 00 1.00
∞
0 00 0.00
00 0.0
100 0 100.0
1.10
26.4
0.01
0.2
99.8
1 20 1.20
20 8 20.8
0 04 0.04
08 0.8
99 2 99.2
1.30
17.7
0.08
1.7
98.3
1.40
15.6
0.12
2.8
97.2
1.50
14.0
0.18
4.0
96.0
2.00
9.5
0.51
11.1
88.9 6
Shaping Antenna Patterns Vertical arrangement of properly phased dipoles allows control Vertical 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) Aperture of Dipoles
Vertical Pattern
Single Dipole
Horizontal Pattern
• 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 pattern measures the gain.
• The little lobes lobes, illustrated in the 4 Dipoles Vertically Stacked
lower section, are secondary minor lobes.
• 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
Gain What is it? Antenna gain is a comparison of the power/field characteristics of a device under test (DUT) to a specified gain standard specified 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 What is Andrew standard? d d? 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 radiating in a perfect d f sphere (not physically possible).
Isotropic Pattern Isotropic Pattern Dipole Pattern
dBi dBd
• A dipole antenna is one radiating element (physically possible). • A gain antenna is two or more radiating elements phased together.
Isotropic (dBi) Dipole (dBd) Dipole (dBd) Gain
3 (dBd) = 5.14 (dBi) 0 (dBd) = 2.14 (dBi)
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Principles Of Antenna Gain Omni Antenna, Antenna Side View
Directional Antennas, Antennas Top View
‐3 dB
0 dd B
0 dd B
60° 60 ‐3 dB
+3 dd B
+3 3 dd B
30°
180° ‐3 dB
‐3 dB
+6 dd B
+6 dd B
15°
90°
‐3 dB ‐3 dB
7.5°
+9 dd B
‐3 dB
+9 dd B
45° ‐3 dB
11
Theoretical Gain Of Antennas (dBd)
# of Rad diators Verticallly Spaced (0.9λ)
3 dB Horizontal Aperture (Influenced by Grounded Back “Plate”) 360 °
180 120 105 ° ° ° 90° 90 60 60° 45 45°
Typical Length of Antenna (ft.) (ft )
33° 33
800/900 MHz
Vertical 1800/190 Beamwidt 0 h
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°
7.5
8.5
9.5
10. 5
12. 5
13. 15.1 5
3
1.5
20°
9
10
11
12
14
15
16.6
4
2
15°
10. 5
11.5
12. 5
13. 5
15. 5
16. 18.1 5
6
3
10°
12
13
14
15
17
18
8
4
7.5° 7.5
3 4.5 4
6
6 7.5 8
9
Could be horizontal radiator pairs for narrow horizontal apertures.
19.6
12
Antenna Gain • Gain (dBi) = Directivity (dBi) – Losses (dB) • Losses:
Conductor Dielectric Impedance Polarization
• 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 diversity q y g y – Lower zoning impact – Best performance in high and medium multipath environments i t Measured data will be presented in the Systems Section
14
Various Radiator Designs
800/900 MHz 800/900 MHz DualPol®
800/900 MHz / PCB DualPol®
1800/1900/UMTS DualPol® Directed Dipole
1800/1900/UMTS PCB DualPol®
800/900 MHz / Log Periodic Vertical Pol
1800/1900/UMTS Vertical Pol
800/900 MHz / DualPol® MAR (Microstrip Annular Ring)
Interleaved Dual Band, DualPol® and MAR (Microstrip Annular Ring) 15
Antenna Basics . . . Cross Polarized Dipoles
Single Vertically Polarized Dipole
Two +/– 45° Polarized Dipoles 16
Feed Harness Construction Feed Harness Construction ASP705
ASP705K
LBX-6513DS
(Old Style)
Series Feed
Center Feed ((Hybrid) y )
Corporate Feed
17
Feed Harness Construction (Continued)
Center Feed (Hybrid)
Series Feed
Advantag es
z
z
Minimum feed losses Si l ffeedd system Simple t
z
z
Disadvant ages
z
BEAMTILT
+2° +1° +1 0° –1°
ASP‐705
–2° 450
455
460
465
470 MHz
Corporate Feed
Frequency independent main lobe direction Reasonably simple feed system
z
Not as versatile as corporate (less bandwidth, less beam shaping)
z
z
Frequency independent main beam direction More beam shaping ability, sidelobe suppression Complex feed system
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)
• Air substrate Ai b – Metal strip spaced above a groundplane – Minimal solder or welded joints Minimal 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 Antenna V ti l P tt Vertical Pattern
24
932DG65T2E‐M P tt Pattern Simulation Si l ti
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 that contains the majority portion of radiated energy.
35° Total Main Lobe
Why is it useful? Shaping of the pattern allows the Shaping 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
Half‐Power Beamwidth H i t l A d V ti l Horizontal And Vertical 1/2 Power Beamwidth
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.
30
30
Why is it useful? 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.
What is Andrew standard? Andrew conforms to the industry standard.
28
Front‐To‐Back Ratio What 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 dual rearward direction. Note that on a dual‐ polarized antenna, it is the sum of co‐pol and cross‐pol patterns.
Why is it useful? y It 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. antenna range testing.
What is Andrew standard?
F/B Ratio @ 180 degrees F/B Ratio @ 180 degrees 0 dB – 25 dB = 25 dB
Each data sheet shows specific performance. In general, traditional dipole and patch elements will yyield 23–28 dB while the Directed Dipole™ style elements will yield 35–40 dB. p y y
29
Sidelobe Level What is it? Sidelobe level is a measure of a particular sidelobe or angular group of sidelobes with group of sidelobes with respect to the main lobe.
Why is it useful?
Sidelobe Level (–20 dB)
Sidelobe level or pattern shaping 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 Suppression Sidelobe Suppression.
How is it measured? It is always measured with respect to the It is always measured with respect to the main lobe in dB.
What is Andrew standard? Andrew conforms to the industry standard. y
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Null Filling What is it? Null filling is an array optimization technique that reduces the null between the lo er lobes in the ele ation plane lower lobes in the elevation plane.
Why is it useful? For arrays with a narrow vertical beam‐ width (less than 12°)), null filling width (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 peak of 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. q y , p yp y To qualify as null fill, we expect no less than 15 and typically 10–12 dB!
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Null Filling I Important For Antennas With Narrow Elevation Beamwidths t tF A t With N El ti B idth
R Received Lev el (dBm)
Null Filled to 16 dB Below Peak 0
Transmit Power = 1 W ‐20
Base Station Antenna Height = 40 m
‐40
B Base Station Antenna Gain = 16 dBd St ti A t G i 16 dBd
‐60
Elevation Beamwidth = 6.5°
‐80 ‐100 100 0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Distance (km)
32
Upper Sidelobe Suppression What is it? Upper sidelobe suppression (USLS) is an array optimization technique that reduces the undesirable sidelobes above the main lobe.
First Upper Sidelobe Suppression
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 first upper sidelobe. id l b
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 designs is to suppress the first upper sidelobe to unity gain or lower. 33
Orthogonality What is it?
δ
The ability of an antenna to discriminate between two waves whose polarization difference is 90 two waves whose polarization difference is 90 degrees.
Why is it useful? Orthogonal arrays within a single antenna allow for polarization diversity. (As opposed to spacial diversity.)
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).
What is Andrew standard? Andrew conforms to the industry standard.
Decorrelation between the Green and Blue Lines Decorrelation between the Green and Blue Lines δ = 0°, XPol = –∞ dB δ = 5°, XPol = –21 dB δ = 10°, XPol = –15 dB δ = 15 15°, XPol XPol = –11 11 dB dB δ = 20°, XPol = –9 dB δ = 45°, XPol = –3 dB δ = 50°, XPol = –2.3 dB δ = 60 60°, XPol XPol = –1 1.2 dB 2 dB δ =70°, XPol = –0.54 dB δ =80°, XPol = –0.13 dB δ =90°, XPol = 0 dB XPol = 20 log ( sin (δ)) XPol = 20 log ( sin (δ)) 34
Cross‐Pol Ratio (CPR) 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).
120° 120 0 -5 -10 -15 -20 -25 -30 -35
Why is it useful? It is a measure of the ability of a cross‐pol array to distinguish between orthogonal waves The better distinguish between orthogonal waves. The better the CPR, the better the performance of polarization diversity.
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. Note: in the rear hemisphere, cross‐pol becomes co‐pol and vice versa.
Typical
-40
Co‐Polarization
120°
Cross‐Polarization (Source @ 90°)
0 -5 -10 -15 -20 -25 -30 -35 -40
Directed 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. Directed Dipole style elements it increases to 15 dB min 35
Horizontal Beam Tracking What is it? It refers to the beam tracking between the two polarization diversity antenna y beams of a +/–45° p over a specified angular range.
120°
Why is it useful? For optimum diversity performance, –45° Array the beams should track as closely as A possible.
+45° A Array
How is it measured? IIt is measured using data collected i d i d ll d 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
Beam Squint Horizontal Boresite
What is it? The amount of pointing error of a given beam referenced to mechanical boresite.
Wh i it Why is it useful? f l?
Squint –3 dB
θ/2 θ
+3 dB
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 1 degree, whichever is greatest. 37
Sector Power Ratio (SPR) 120° 120 What is it? SPR is a ratio expressed in percentage of the power outside the desired sector p to 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.
What is Andrew standard? Andrew Directed Dipole™ style antennas have SPR’s typically less than 2 percent.
Desired Undesired
300 60 SPR (%) =60
Σ P
Undesired
X 100
Σ P
300
Desired
38
Antenna–Based System Improvements K A t Key Antenna Parameters To Examine Closely P t T E i Cl l 932LG
Standard 85° Panel Antenna
Directed Dipole™ Directed Dipole
–7 dB
74° 74°
–16 dB
–35 dB
120° Cone of Great Silence with >40 dB Front‐to‐Back Ratio
Roll off at ‐/+ 60° ‐10 dB points Horizontal Ant/Ant Isolation Next Sector Ant/Ant Isolation Cone of Silence
–6 dB
83° 83°
–12 dB
–18 dB
60° Area of Poor Silence with >27 dB Front‐to‐Back Ratio
39
Key Antenna Pattern Objectives Azimuth Beam • Beam tracking vs. frequency
1
1
1
• Squint
1
1
1
• Roll‐off past the 3 dB points
1
2
3
• Front‐to‐back ratio
1
1
2
• Cross‐pol beam tracking
1
1
1
• Beam tracking vs. frequency
1
2
3
Ratings:
• Upper sidelobe suppression
1
2
3
1 = Always important
• Lower null fill
3
3
2
2 = Sometimes important
• Cross‐pol beam tracking
2
2
3
3 = Seldom important
Li i d Limited to sub‐bands on broadband models bb d b db d d l
Elevation Beam Elevation Beam
40
Key Antenna Pattern Objectives (Continued) Downtilt • Electrical vs. mechanical tilt
1
1
3
• Absolute tilt
2
2
3
• Electrical tilt vs. frequency
1
2
3
• Effective gain on the horizon Effective gain on the horizon
1
2
3
2
1
1
Gain • Close to the theoretical value (directivity minus losses)
Note: Pattern shaping reduces gain.
Ratings: 1 = Always important 2 = Sometimes important 3 = Seldom important
41
Advanced Antenna Technology Adaptive Array (AA) d i ( )
• Planar array Planar array • External digital signal processing (DSP) controls the antenna pattern
• 4 4, 6, and 8 column vertical pol designs 6 and 8 column vertical pol designs for WiMAX and TD‐SCDMA* • Often calibration ports are used
• A unique beam tracks each mobile 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
Advanced Antenna Technology MIMO S MIMO Systems
2 x 2 MIMO Spatial Multiplexing
• Multiple Input Multiple Output p p p p (MIMO)
• A DualPol® RET for 2x2 MIMO, two separated for 4x4 MIMO
• External DSP extracts signal from interference
• 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
Advanced Antenna Technology ® Antenna Family SSmartBeam B A F il
• 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 – RAS Remote Remote Azimuth Steering Azimuth Steering (+/– (+/ 30 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
Advanced Antenna Technology ® SSmartBeam B 3‐Way Model
35°
Azimuth patterns measured at d t 1710–2180 MHz with no radome.
65°
90°
105°
45
Advanced Antenna Technology ® SSmartBeam B 3‐Way Model
35°
Elevation patterns measured at d t 1710–2180 MHz with no radome.
65°
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 p use of antennas with different horizontal apertures? Criteria • Area Area of service indifference between adjacent sectors of service indifference between adjacent sectors (ping‐pong area) • For comparison, use 6 dB differentials • Antenna gain and overall sector coverage comparisons
48
3 x 120° Antennas 120° Horizontal Overlay Pattern H i t l O l P tt 0 -5 -10
Examples
-15
VPol
-20 -25 25
Low Band Low Band
-30
DB874H120 DB878H120
-35
49°° 49
-40
3 dB
49
3 x 90° Antennas 90° Horizontal Overlay Pattern H i t l O l P tt 0
Examples
-5 -10
XPol
-15
Low Band DB854DG90 DB842H90 DB856DG90 DB844H90 DB858DG90 DB848H90 LBX‐9012 LBV‐9012 LBX‐9013
-20 -25 -30
44°
VPol
-35 -40
High Band
5 dB 5 dB
DB932DG90 DB950G85 HBX‐9016 UMWD‐09014B UMWD‐09016
UMW‐9015
50
3 x 65° Antennas Examples
65° Horizontal Overlay Pattern H i t l O l P tt
XPol 0
Low Band CTSDG 06513 CTSDG‐06513 DB844H65 CTSDG‐06515 DB848H65 CTSDG‐06516 LBV‐6513 DB854DG65 DB856DG65 DB858DG65 LBX‐6513 LBX‐6516
-5 -10 -15 -20 -25 -30 -35
19°
VPol
-40
High Band
10 dB
UMWD‐06513 UMWD 06516 UMWD‐06516 UMWD‐06517 HBX‐6516 HBX‐6517
PCS‐06509 HBV 6516 HBV‐6516 HBV‐6517
51
Special Narrow Beam Applications
4‐Sector Site (45°)
Road
Repeater Narrow Donor, Wide Coverage Antennas
6‐Sector Site (33°)
Rural Roadway
52
Test Drive Route
35
183
CELL SITE
N
53
Polarization Diversity Tests
DB854HV90 DB854DD90
1
2
DRIVE TESTS
+45°/‐45° ((Slant 45°))
0°/90° ((H/V) / )
A
HANDHELD
1A
2A
B
MOBILE
1B
2B
Test A
. Test B
54
Slant 45° / Hand‐Held In Car S Space Diversity vs. Slanted +45°/–45° Di it Sl t d +45°/ 45° ‐40
TEST 1A
Test Set‐Up and Uplink Signal Strength Measurements DB833
DB854DD90
A
E
B
Green G
9dB
‐50
DB833
Red
9dB
Black
Blue
Signal Sttrength (dB Bm)
11dB 7.5 ft.
‐60
‐70
‐80 moving away from tower
moving towards tower
‐90
‐100
moving crossface Uplink Si Signal Strength lS h
Vert L f Left
Vert Ri h Right
Slant Di Div
Slant Di Div
55
Slant 45° / Hand‐Held In Car S Space Diversity vs. Slanted +45°/–45° Di it Sl t d +45°/ 45°
TEST 1A
Difference Between Strongest Uplink Signals 16
Signal Strength ((dB)
12 8 4
Slant ±45° I Improvement
0 ‐4 ‐8 Difference Between Polarization Diversity and Space Diversity Average Difference
56
Slant 45° / Mobile With Glass Mount
S Space Diversity vs. Slanted +45°/–45° Di it Sl t d +45°/ 45° ‐40
Test Set‐Up and Uplink Signal Strength Measurements DB833
DB854DD90
A
E
Signal SStrength (dB Bm)
Black
Red
TEST 1B TEST 1B
B
Green
9dB
‐50
DB833 9dB Blue
11dB 7.5 ft.
‐60
‐70
moving away from tower
moving towards moving towards tower
‐80
‐90
moving crossface Uplink Si Signal Strength l St th
Vert Left
Vert Right
Slant Div
Slant Div 57
Slant 45° / Mobile With Glass Mount
S Space Diversity vs. Slanted +45°/–45° Di it Sl t d +45°/ 45°
TEST 1B
Difference Between Strongest Uplink Signals 16
Signall Strength ((dB)
12 8 4 0 ‐4
Slant ±45° Degradation
‐8
Difference Between Polarization Diversity and Space Diversity Average Difference Average Difference
58
Rysavy Research
59
Future Technology Focus Shannon’s Law 6 Shannon bound Shannon bound with 3dB margin E V -DO DO 802.16 HSD P A
5 achieva able rate (bps/Hz)
• Figure 16 shows that HSDPA,1xEV‐DO, and 802.16e are all within 2‐3 dB of the Shannon bound of the Shannon bound, indicating that from a link layer perspective, there is not much room for improvement improvement. • This figure demonstrates that the focus of future technology enhancements should be on improving h ld b i i system performance aspects that improve and maximize the experienced SNRs in the system instead of t i t d f investigating new air interfaces that attempt to improve the link layer performance. f
4
3
Peter Rysavy of Rysavy Research, “Data Capabilities: GPRS to HSDPA and Beyond”, 3G Americas, September 2005
2
1
0 -15
-10
-5
5 0 required SNR (dB)
10
15
20
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
1 Peter Rysavy of Rysavy Research, “Data Capabilities: GPRS to HSDPA and Beyond”, 3G
Americas, September 2005
60
The Impact L Lower Co‐Channel Interference/Better Capacity And Quality C Ch lI t f /B tt C it A d Q lit In a three sector site, traditional antennas produce a high degree of imperfect power control or sector overlap. t l t l Imperfect sectorization presents opportunities for: • • • •
Traditional Flat Panels 65°
90°
Increased softer hand‐offs Interfering signals Dropped calls Reduced capacity
The rapid roll‐off of the lower lobes of the Andrew Andrew Directed Dipole™ Directed Dipole™ antennas create larger, better 65° defined ‘cones of silence’ behind the array behind the array.
90°
• Much smaller softer hand‐off area • Dramatic call quality improvement • 5%–10% capacity enhancement
61
120° Sector Overlay Issues 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 . . . 15 Percen ntage of capacitty loss
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 1998
10 5 0 15 10 5 0 Overlapping angle in degree Overlapping angle in degree
Qualitatively, excessive overlay also reduces capacity of TDMA and GSM systems.
62
Hard, Soft, and Softer Handoffs • H Hard Handoff d H d ff – Used in time division multiplex systems – Switches from one frequency to another Switches 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 handoffs • Softer Handoff – Similar to soft handoff except combines signals from p g multiple adjacent sectors 63
Soft and Softer Handoff Examples Soft and Softer Handoff Examples Softer Softer Handoff
Two‐Way Soft Handoff Three‐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 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! 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 Downtilt Pattern 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 110
100
90
80
110
70
120
90
80
70
120
60
130
100
140
60
130
50 140
40
150
50 40
150
30
160
30
160
20
20
170
10
170
10
180
0
180
0
190
350
190
350
340
200 210
330 320
220 230
310 300
240 250
260
270
280
290
Elevation Pattern Mechanical Tilt
200
340
210
330 320
220 230
310 240
300 250
260
270
280
290
Azimuth Pattern 0° 4° 6° 8° 10°
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 g y g p fp will generate patterns that look up g p p or look down. • The degree of beam tilt is a function of the phase shift of one dipole relative to the adjacent dipole.
Generating Beam Tilt Dipoles Fed In Phase p
Dipoles Fed Out of Phase p f
Energy in
Exciter
Phase Exciter
71
Electrical Downtilt P tt Pattern Analogy—Forming A Cone Out Of A Disk A l F i AC O t Of A Di k
Electrical tilt causes . . . • Beam peak to tilt below horizon • Back lobe to tilt below horizon B k l b t tilt b l h i • At ± 90°, tilt below horizon • All the pattern tilts All the pattern tilts
Cone of the of the Beam Peak Pattern
72
Electrical Downtilt Coverage 110
100
90
80
110
70
120
90
80
70
120
60
150
50
140
40
140
60
130
50
130
100
40
150
30
160
30
160
20
20
170
10
170
10
180
0
180
0
190
350
190
350
200
340
210
330 320
220 230
310 300
240 250
260
270
280
290
Ele ation Pattern Elevation Pattern Electrical Tilt
200
340
210
330 320
220 230
310 240
300 250
260
270
280
290
A im th Pattern Azimuth Pattern 0° 4° 6° 8° 10°
73
Mechanical Vs. Electrical Downtilt 340
350
0
10
20 30
330
40
320
50
310
60
300 290
70 80
280
90
270
100
260
110
250
120
240 130
230 140
220 210
150 200
190
180
170
160
Mechanical
Electrical
74
Effects of Blooming on Sector Performance
M( )E( ) Tilt Angle Crossover
M0E0 & M0E7 ‐‐‐‐ 17°
10 dB
M7E7 ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ 25°
6 dB
M14E0 ‐‐‐‐‐‐‐‐‐‐‐‐‐‐ 29°
4 dB
75
Combined Electrical and Mechanical Tilt 4 Foot Antenna at 780 MHz
LNX-6512 Blooming (Calc) M0E0 0% M4E0 3.1%
70%
M7E0 9.2% M9E0 16.9%
60%
M11E0 32.3%
M11E0 32.3% M0E4 0%
M-tilt (% % of VBW)
M9E4 34 34.4% 4%
50%
M4E4 6.3%
M9E0 16.9%
M7E4 18.8%
M7E4 18.8%
40%
M7E0 9.2%
M0E8 0% M4E8 12.3%
M5E8 18 18.5% 5%
30% M4E4 6.3%
20%
M9E4 34.4%
M7E8 36.7%
M4E0 3.1%
M5E8 18.5%
M5E10 24.6%
M7E8 36.7%
M4E10 15.4%
M0E10 0%
M4E8 12.3%
M4E10 15.4%
M3E15 39.4%
M5E10 24.6%
M2E15 16.7%
10% M0E0 0%
M0E4 0%
M0E8 0%
0% 0%
10%
20%
30%
40%
M0
50%
E1 0
0%
60%
E-tilt (% of VBW)
70%
M1E15 6.1% M0 E1 50 %
80%
90%
M0E15 0% M1E15 6.1% M2E15 16.7%
100%
M3E15 39.4% 10% Blooming 20% Blooming
76
Combined Electrical and Mechanical Tilt 8 Foot Antenna at 780 MHz
LNX-6515 Blooming (Calc) 70% M6E0 40.5%
M6E2 78.1%
M0E0 0%
60%
M2E0 2.9%
M-tilt (% of VBW)
M4E0 13.1%
50%
M6E0 40.5%
M4E2 25.0%
M8E0 97.3%
M4E4 46.9%
M4E0 13.1%
M0E2 0.0%
40%
M2E2 6.3% M4E2 25.0%
30% 20%
10% Blooming
M2E8 57.8%
M2E4 10.4%
M2E0 2.9%
M6E2 78.1% M0E4 0.0%
M2E2 6.3%
M2E4 10.4%
M1E8 15.6%
M4E4 46.9%
10%
M0E8 0.0%
M0E0 0%
M0E2 0.0%
M0E8 0.0%
M0E4 0.0%
M1E8 15.6%
0%
M2E8 57.8%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
20% Blooming
E-tilt (% of VBW)
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:
33º HBW M‐tilt10% Bloom = (VBW – E‐tilt)/1.5 90º HBW M‐tilt10% Bloom = (VBW – E‐tilt)/3.3
78
Remote Electrical Downtilt (RET) O ti i ti Optimization
ATM200‐002 RET Device (Actuator)
Local PC
ATC200 LITE USB ATC200‐LITE‐USB Portable Controller
L l PC Local PC
ANMS™ Remote Locations
ATC300‐1000 Rack Mount Controller Network Server
79
Intermod Interference Wh ? Where? F3
F1 Tx F1
Rx R F3
F2
Tx F1
F2
Receiver‐Produced
Transmitter‐Produced
Tx F2
Tx F2
F1 F2
F1 F3
Tx1 F2 Tx2
Rx F3
Elsewhere
Rx F3 Tx1 Tx2
C O M B
F3
DUP Rx3 RF Path‐Produced RF Path Produced
80
High Band P d tF Product Frequencies, Two‐Signal IM i T Si l IM FIM = nF1 ± mF2 Example: F1 = 1945 MHz; F2 = 1930 MHz
n
m
Product P d t Order
1
1
Second
2
1
Third
1
2
Third
2
2
Fourth
3
2
Fifth
2
3
Fifth
Product P d t Formulae 1F1 + 1F2 1F1 – 1F2 2F1 + 1F2 *2F1 – 1F2 2F2 + 1F1 *2F2 – 1F1 2F1 + 2F2 2F1 – 2F2 3F1 + 2F2 *3F1 – 2F2 3F2 + 2F1 *3F2 – 2F1
Product P d t Frequencies (MHz) 3875 15 5820 1960 5805 1915 7750 30 9695 1975 9680 1900
*Odd d diff *Odd‐order difference products fall in‐band. d f ll i b d
81
Two‐Signal IM Odd O d Diff Odd‐Order Difference Products P d t Example: F1 = 1945 MHz; F2 = 1930 MHz ΔF = F1 ‐ F2 = 15 F2 1930
F1 1945 ΔF dBc
2F2 – F1 1915
3F2 – 2F1 1900
ΔF
2ΔF 5th
2F1 – F2 1960
3rd
ΔF F2
F1
dBm
3F1 – 2F2 1975
2ΔF 3rd
5th
Third Order: F1 + ΔF; F2 ‐ ΔF Fifth Order: F1 + 2ΔF; F2 ‐ 2ΔF Seventh Order: F1 + 3ΔF; F2 ‐ 3ΔF Higher than the highest – lower than the lowest – Higher than the highest – lower than the lowest – none in‐between none in‐between
82
PCS A Band Intermodulation 11th 1855
9th 1870
7th 1885
5th 1900
3rd 1915
Channel Bandwidth Block (MHz) Frequencies C 30 1895–1910 1975–1990 1895–1910, 1975–1990 C1 15 1902.5–1910, 1982.5–1990 C2 15 1895–1902.5, 1975–1982.5 C3 10 1895–1900, 1975–1980 C4 10 1900–1905, 1980–1985 C5 10 1905–1910, 1905 1910, 1985 1985–1990 1990
1930
1945
FCC Broadband PCS Band Plan 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
PCS A & F Band Intermodulation 3rd 1895
Channel Bandwidth Block (MHz) Frequencies C 30 1895–1910 1975–1990 1895–1910, 1975–1990 C1 15 1902.5–1910, 1982.5–1990 C2 15 1895–1902.5, 1975–‐1982.5 C3 10 1895–1900, 1975–1980 C4 10 1900–1905, 1980–1985 C5 10 1905–1910, 1905 1910, 1985 1985–1990 1990
1935
1975
FCC Broadband PCS Band Plan 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
Causes Of IMD • Ferromagnetic materials in the current path: – Steel – Nickel plating or underplating
• Current disruption: C di i – Loosely contacting surfaces – Non‐conductive oxide layers between contact surfaces
85
System VSWR Calculator System VSWR Calculator Version 9.0 Frequency (MHz): Component Used? No No No No No No No N No No No No No Yes
2 2 2 2 2 2 2 2 2 2 2 2 1
2 2 2 2 2 2 2 2 2 2 2 2 1
850.00
18-Mar-09
System Component
Max. VSWR
Return Loss (dB)
Antenna or Load Jumper Tower Mounted Amp Jumper Top Diplexer or Bias Tee Jumper Main Feed Line Jumper Bi T Bias Tee Jumper Surge Suppressor Jumper Bottom Diplexer or Duplexer Jumper
1 50 1.50 1.05 1.20 1.09 1.15 1.09 1.07 1.09 1 15 1.15 1.09 1.07 1.09 1.20 1.08
13.98 13 98 32.26 20.83 27.32 23.13 27.32 29.42 27.32 23 13 23.13 27.32 29.42 27.32 20.83 28.30
Andrew
CommScope
Cable Type / Component Loss (dB) VXL7-50 2 LDF4-50A
0.20 2 0.20 2.00 8 4 0 10 0.10 2.00 0.10 3.00 0.10 FSJ4-50B 1.00
Cable Length (m)
Cable Length (ft)
1.83
6.00
1.83
6.00
1.83 200.00 30.48 11 00 11.00 1.83
6.00 656.17 100.00 36 09 36.09 6.00
1.83
6.00
27.30
89.57
Ins Loss w/2 Conn (dB) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0 00 0.00 0.00 0.00 0.00 0.00 3.00
% of Est. Reflections at System input Reflection 87 2% 87.2% 0 1003 0.1003 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 0 0% 0.0% 0 0000 0.0000 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 0.0% 0.0000 12.8% 0.0385 100.0%
Legacy Jumper / TL Cables 1/2 iinch h Superflexible S fl ibl Copper C 1/2 inch Foam Copper
FSJ4-50B FSJ4 50B LDF4-50A
1/2 inch Superflexible Aluminum 1/2 inch Foam Aluminum
Legacy Transmission Lines 7/8 inch Copper 1 1/4 inch Copper 1 5/8 inch Copper 7/8 inch Very Flexible Copper 1 1/4 inch Very Flexible Copper 1 5/8 inch Very Flexible Copper 7/8 inch Virtual Air Copper Yes
1 5/8 inch Virtual Air Copper 7/8 inch Aluminum 1 1/4 inch Aluminum 1 5/8 inch Aluminum
Andrew
LDF5-50A LDF6-50 LDF7-50A LDF7 50A VXL5-50 VXL6-50 VXL7-50 AVA5-50 AVA7-50 AL5-50 AL7-50
CR 540 SFX 500 FXL 540
Estimated Conn Loss ( 2per cable)
0 028 0.028
Typical System Reflection: Typical System VSWR: Typical System Return Loss (dB):
0.1074 1.24 19.4
Worst System Reflection: Worst System VSWR: Worst System Return Loss (dB):
0.1387 1.32 17.2
CommScope
CR 1070 CR 1480 CR 1873
Total Insertion Loss (dB): Return Loss to VSWR converter
FXL 780 FXL 1480 FXL 1873
Return Loss (dB) 17.00
3.00 Feet to meters converter
VSWR
Feet
meters
1.33
100.00
30.48
No
86
Possible CascadedPossible Possible Cascaded VSWR Results VSWR Results results (at a given frequency) when Antenna and TMA are interconnected 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 aware that be th t it is i possible!
From http://www.home.agilent.com/agilent/editorial.jspx?cc=US&lc=eng&ckey=895674&nid= From http://www home agilent com/agilent/editorial jspx?cc=US&lc=eng&ckey=895674&nid=‐35131 35131.0.00&id=895674 0 00&id=895674
87
Recommended Antenna/TMA Qualification Test
Antenna
6 foot LDF4‐50A Adapter or jumper to bypass TMA
50 ohm load
6 foot LDF4‐50A
TMA
12 foot LDF4‐50A
Transmission Line
20 foot FSJ4‐50
Antenna Return Loss Diagram
TMA
12 foot LDF4‐50A
Transmission Transmission Line
20 foot 20 foot FSJ4‐50
TMA Return Loss Diagram
88
Attenuation Provided By Vertical Separation Of Dipole Antennas 70
60
Isolation in dB
50
40
30
20
10 1 (0.3) (30.48)
2 (0.61)
3 (0.91)
5 (1.52)
10 (3.05)
20 (6.1)
30 (9.14)
50 (15.24)
100
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 for the antenna gains. t i
89
Attenuation Provided By Horizontal Separation Of Dipole Antennas 80
70
Isolation in dB
60
50
40
30
20 10 (3.05) (304.8)
20 (6.1)
30 (9.14)
50 (15.24)
100 (30.48)
200 (60.96)
300 (91.44)
500 (152.4)
1000
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 Conductive (metallic) obstruction in the path of C d i ( lli ) b i i h h f 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
Pattern Distortions Sid Of B ildi M Side Of Building Mounting ti
Building
92
90° Horizontal Pattern Ob t ti @ 10 dB P i t Obstruction @ –10 dB Point 340
350
0
10
20
0
330 320
30 40
-5 -10
310
50
-15
300
880 MHz
60
-20 290
70
-25 25 -30
280
80
-35 270
90
-40
260
0° –10 dB Point
100
250
110
240
120 230
Antenna
Building Corner
130 220
140 210
150 200
190 180
170
160
93
90° Horizontal Pattern Ob t ti @ 6 dB P i t Obstruction @ –6 dB Point 340
350
0
10
20
0
330 320
30 40
-5 -10
310
50
-15
300
880 MHz
60
-20 290
0
-25 25 -30
280
80
-35 270
90
-40
260
0°
–6 dB Point
100
250
110
240
120 230
Antenna
Building Corner
130 220
140 210
150 200
190 180
170
160
94
90° Horizontal Pattern Ob t ti @ 3 dB P i t Obstruction @ –3 dB Point 340
350
0
10
20
0
330 320
30 40
-5 -10
310
50
-15
300
880 MHz
60
-20 290
0
-25 25 -30
280
80
-35 270
90
-40
260
0°
Building Corner
100
250
110
240
120 230
–3 dB Point
Antenna
130 220
140 210
150 200
190 180
170
160
95
90° Horizontal Pattern 0 51λ Diameter Obstacle @ 0° 0.51λ Di Ob l @ 0° 340
350
0
10
20
0
330 320
30 40
-5 -10
310
50
-15
300
880 MHz
60
-20 290
0
-25 25 -30
280
80
-35 270
90
-40
260
100
250
0° 12λ
110
240
120 230
Antenna
130 220
140 210
150 200
190 180
170
160
96
90° Horizontal Pattern 0 51λ Diameter Obstacle @ 45° 0.51λ Di t Ob t l @ 45° 340
350
0
10
20
0
330 320
30 40
-5 5 -10
310
50
-15
300
880 MHz
60
-20 290
0
-25 25 -30
280
80
-35 270
90
-40
260
45°
100
250
8λ
110
240
120 230
Antenna
130 220
140 210
150 200
190 180
170
160
97
90° Horizontal Pattern 0 51λ Diameter Obstacle @ 60° 0.51λ Di t Ob t l @ 60° 340
350
0
10
20
0
330 320
30 40
-5 5 -10
310
50
-15
300
880 MHz
60
-20 290
0
-25 25 -30
280
80
-35 270
90
-40
60°
260
100
250
6λ
110
240
120 230
Antenna
130 220
140 210
150 200
190 180
170
160
Additional information on metal obstructions can also be found online at www akpce com/page2/page2 html www.akpce.com/page2/page2.html.
98
90° Horizontal Pattern 0 51λ Diameter Obstacle @ 80° 0.51λ Di t Ob t l @ 80° 340
350
0
10
20
0
330 320
30 40
-5 5 -10
310
50
-15
300
880 MHz
60
-20 290
0
-25 25 -30
280
80
-35 270
90
-40
260
100
250
80°
110
240
120 230
3λ
Antenna
130 220
140 210
150 200
190 180
170
160
Additional information on metal obstructions can also be found online at www akpce com/page2/page2 html www.akpce.com/page2/page2.html.
99
General Rule A Area That Needs To Be Free Of Obstructions (> 0.51λ) Th t N d T B F Of Ob t ti ( 0 51λ) Maximum Gain > 12 WL
3 dB Point (45°)) (45 6 dB Point ( ) (60°)
WL
> 3 WL > 3 WL
10 dB Point (80– 90°)
Antenna 90° horizontal (3 dB) beamwidth
100
Pattern Distortions D
θ
d
d tan θ = D d = D x tan tan θ θ tan 1° = 0.01745 for 0° < θ< 10° : tan θ = θ x tan 1° Note: tan 10° = 0.1763 10 x 0.01745 = 0.1745 Note: tan 10 = 0 1763 10 x 0 01745 = 0 1745 101
Gain Points Of A Typical Main Lobe
θº θ° Relative to Maximum Gain
Vertical i l Beam Width= 2 x θ° (–3 dB point)
–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
90°° PCS Antennaa
Fiberglass Panel
Dim “A”
103
Performance Of 90° PCS Antenna Behind Camouflage (¼" Fiberglass)
120°
FIBERGLASS PANEL
110° DIM “A”
Horizontal Ap perture
100° 90° 80° 1/2 λ
1/4 λ
1‐1/2 λ
1 λ
3/4 λ
2 λ
70° 0
1
2
3
4
5
6
7
8
9
10
11
12
Distance of Camouflage (Inches) (Dim. A)
104
Performance Of 90° PCS Antenna
)
Behind Camouflage (¼" Fiberglass 1.7 16 1.6
FIBERGLASS PANEL
1.5
VSWR (Worsst Case)
DIM “A” DIM “A”
1.4 1.3 1/4 λ
1/2 λ
1‐1/2 λ
1 λ
2 λ
1.2 0
1
2
3
4
5
6
7
8
9
10
11
12
Distance of Camouflage (Inches) (Dim. A) W/Plain Façade W/Ribbed Façade Without Facade W/Plain Façade W/Ribbed Façade Without Facade
105
Distance From Fiberglass 0° 330°
30°
300°
90°° 90
0°
300°
60°
270°
60°
90°
-55
-55
-50
-50 -45
-45 -40
-40
240°
120°
-35 -25 -20
120°
-35 30 -30
-30
210°
102°° 102
270°
90°
240°
30°
330°
210°
150°
-25 -20
150°
180°
180° 0°
No Fiberglass
330°
30°
300° 300
68°° 68
3" to Fiberglass
60°
270°
90° -50 -45 -40 -35
240°
120°
-30 -25
210°
-20 -15
150°
180°
1 5" to Fiberglass 1.5 to Fiberglass 106
Distance From Fiberglass 0° 330 °
30°
300°
0°
77°° 77
330°
300 °
60°
270°
90° -50
-45
-45
-40
-40
-35
-35
240 °
120°
-30 -20 -15
120 °
-30 -25
-25
210°
210 °
150°
180° 0°
4" to Fiberglass
330°
30°
300° 300
108°° 108
112°° 112 60°
270 °
90° -50
240 °
30°
-20 -15
180 °
150 °
6" to Fiberglass
60°°
270 °
90° -50 -45 -40 -35
240°
120°
-30 -25
210 °
-20 -15
180 °
150 °
9" to Fiberglass 9 to Fiberglass 107
