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IPSTAR User Terminal Installation Review
IPSTAR Training Department

1/20/2011 2
Skynet MPS Setup
TX cable (RG-11)
RX cable
(RG-6, RG-
11)
ATA
Two-way splitter
IRD
Rx attn
Tx attn

1/20/2011 3
Power Measurement in decibel (dB)
• Decibel (dB) is a way of expressing power level as a ratio between two signals
Gain (dB) = 10 log (P2 / P1)
• Conventionally gain is expressed as positive dB value while attenuation or loss is
expressed as negative dB value or negative gain.
• Decibels can also be expressed relative to a reference power value such as dBW,
dBm.

1/20/2011 4
Satellite Link Performance
Es/No is the measurement of the satellite link performance before demodulation.
Es (dB) = _________ Energy per symbol ___________
No Noise power per Hertz (Noise Spectrum Density)

Feed Assembly

1/20/2011 6
Feed Assembly Set
• Feed assembly set is composed of BUC, LNB, TRF, OMT, and feed horn.
• It had been tested for air leakage so it is not recommended to take apart each
component.
BUC
TRF
OMT
Feed horn
LNB

1/20/2011 7
Low Noise Block-down converter (LNB)
• LNB functions:
– convert downlink Ku band signal to L-band frequency
– amplify signal before sending it to be demodulated.
• LNB receives electric power from coaxial cable

LO Freq. 9.4 GHz 9. 65 GHz 10.6 GHz
Picture
Input 10.95 – 11.2 GHz 11.20 – 11.70 GHz 11.5 – 12.75 GHz
Output 1550 – 1800 MHz 1550 – 2250 MHz 900 – 2150 MHz
Stability
+/- 500 KHz (Max)
@ -30 oC to 50oC
+/- 675 KHz (Max)
+/- 500 KHz (Max)
@ -30 oC to 50oC
Noise Figure
(over temp)
0.8 (MTI), 0.9dB
(NJRC)
0.8 dB (Typical) 0.9 dB(Typical)
Source: from MTI and NJRC
• In an amplifier, the noise generated by the amplifier itself is usually measured as
Noise Figure in dB
LNB Specifications

1/20/2011 9
Block diagram of LNB
• LNB uses its local oscillator (LO) for frequency down conversion.
• LNB has built-in LNA (Low Noise Amplifier) with very low noise figure so it would not
add noise to the signal it amplifies.

IPSTAR Downlink Frequency Plan
Beam Type
Ku-Band
Frequency (GHz)
L-Band
Frequency
(MHz)
LNB LO
Frequency
Polarization
Spot Beams 12.2 – 12.750 1600 – 2150 10.6 GHz Vertical
Augment and
Shaped Beams
10.95 – 11.2 1550 – 1800 9.4 GHz Vertical *
Broadcast
Beams
11.5 – 11.7 1850 – 2050 9.65 GHz Vertical
* Except China and Indonesia’s shaped beams use Horizontal

1/20/2011 11
Block Diagram of BUC
• BUC uses internal LO for frequency up conversion.
• BUC amplifies the signal with SSPA (Solid State Power Amplifier).

1/20/2011 12
Block Up Converter (BUC)
• BUC functions:
– convert the transmit L-band signal to the uplink Ku band frequency
– amplify signal before sending the it to the feedhorn.
• BUC also receives electric power from coaxial cable.

BUC Table
BUC MTI NJRC
Picture
Input 950 MHz – 1450 MHz 950 MHz – 1450 MHz
Output 14 – 14.5 GHz 14 – 14.5 GHz
LO Frequency 13.05 GHz 13.05 GHz
Conversion Gain 50 dB 50 dB
Output Power @ P1dB 30 dBm 30 dBm
Source: from MTI and NJRC:: 1W BUC

IPSTAR Uplink Frequency Plan
Beam Type
Ku-Band
Frequency (GHz)
L-Band
Frequency
(MHz)
BUC LO
Frequency
Polarization
Spot Beams 14.0 – 14.375 950 – 1325 13.05 GHz Horizontal
Augment and
Shaped Beams
14.3885 – 14.5 1338.5 - 1450 13.05 GHz Horizontal *
* Except China and Indonesia’s shaped beams use Vertical

1/20/2011 15
Transmit Reject Filter (TRF)
• TRF helps to block any leaking transmit signal out of OMT from overloading the LNB.
It is usually a piece of waveguide with internal resonator elements
• Sometimes TRF is integrated into the OMT or feed system, or even into the LNB.
TRF

1/20/2011 16
What is a Waveguide?
• Waveguide is a hollow tube that carries microwave signals. Design to be used at a
higher frequency, it has much less loss than coaxial cable.
• Waveguide connectors are called flanges. Connections between waveguides are
made by inserting bolts through holes around the flanges.

1/20/2011 17
Orthogonal Mode Transducer (OMT)
• OMT is a combiner that connects both the transmit signal from BUC to feedhorn,
and received signal from feed horn to LNB, respectively
• OMT is able to direct the transmit and received waves according to their
polarizations.
OMT

1/20/2011 18
Feed Horn
• Feed Horn launches transmit waves as a wide "spray" towards the antenna reflector,
which then focuses them into a narrow beam to the satellite.
• Each feed assembly set is designed to match with a particular antenna. Installer
should only use the approved feed system components with antenna; otherwise, the
antenna may not meet its performance specifications, and is likely to generate
interference to other systems.
• In order to obtain maximum efficiency, the feed horn must be at the correct distance
from the center of the dish, and properly oriented perpendicular to the antenna.
Feed Horn
Front view of feed horn

1/20/2011 19
User Terminal Block Diagram
Ku-bandL- bandTransmit signal:
L-bandReceive signal: Ku-band
Antenna
Reflector

Antenna

1/20/2011 21
IPSTAR Antenna
Reflector Size 0.84m 1.2m 1.8m
Picture
Antenna Type Offset Offset Offset
Reflector Material
metal reflector with
rolled aluminum
edge
Glass Fiber
Reinforced
Polyester reflector
with iron mesh
Glass Fiber
Reinforced
Polyester reflector
with iron mesh
Polarization
Adjustment
Rotating dish Rotating feed Rotating feed
Elevation
Adjustment
0°-90° Continuous 10°-90° Continuous 10°-90° Continuous
Azimuth
Adjustment
360° Continuous 360° Continuous
•360° Continuous ,
± 10° Fine Adjust

Type of Antenna
Symmetric (Prime focus) antenna Offset antenna
Advantage - lifting higher elevation angle
- no feed horn blockage
- lower noise due to the feed looks toward the lower
temperature sky rather than high temperature ground
- avoiding rain collection inside the reflector
- ease to tweak in cross-polarization setting
Disadvantage – large side lobes and wider beam width (less directivity)
- prone to misalignment and interference

Antenna Radiation Pattern
Antenna provides different gains at various directions.

Size of Antenna versus Beamwidth
At a given frequency, if the diameter of the antenna is smaller, the
gain decreases and the beamwidth increases.

• Too smaller the size of antenna or poor antenna assembly/alignment
can cause lower gain, wider beamwidth, and larger sidelobes.
• The result is the performance drops because antenna receives from
nearby satellites and also generates interference to others.
Effects of Antenna Pattern

Installer must ensure:
• Clear Line of Sight (LOS): no obstacles (e.g buildings, trees)
• Strong antenna foundation
• Peak the antenna towards satellite
Consequences of Antenna Mispoint :
At Transmit Path:
• Cause transmission loss
• Interfere to adjacent satellite
At Receive Path:
• Poor receive quality
• Interfered by signals from adjacent satellites
• Get unwanted signals from surroundings
Effects of Antenna Pattern

Sun Transit Outage
SUN
SATELLITE
EARTH STATION
Beamwidth
• Due to the transit of the sun within the
beamwidth of the earth station antenna,
• Sun appears as an extremely noisy source
and blanks out the signal from satellite.
• This phenomenon lasts for 6 days around
the equinox for a short duration in each day.

How to check the time of Sun Outage for IPSTAR?
The customer can access the following website to check the sun outage time by keying
their site location and selecting the iPSTAR satellite, Link :
http://sunoutage.thaicom.net/cgi-bin/sed/outage_input.pl

Antenna Assembly

1/20/2011 30
Liquid-filled Level
1. AZ/EL/Skew Cap Mount and Hardware 2. Detail of AZ/EL/Skew Cap Mount
84cm Antenna Assembly
**Refer to antenna assembly manual for more details.**

1/20/2011 31
5. Connect Feed Arm to the reflector 6. Set feed assembly initial position & Connect
it to the feed support arm

1/20/2011 32
Liquid-filled Level
3. Assemble AZ/EL/Skew Cap Mount
on reflector
4. Connect Reflector on pipe
**Refer to antenna assembly manual for more details.**

1/20/2011 33
Liquid-filled Level
1. AZ/EL Cap Mount 2. Assemble AZ/EL Cap Mount on reflector
1.2m Antenna Assembly

1/20/2011 34
Liquid-filled Level
3. Connect Reflector on pipe 4. Side Feed Legs Installation

1/20/2011 35
5. Bottom Feed Leg Installation 6. Connect Feed Legs & Junction Block

1/20/2011 36
7. Connect Feed Assembly to Reflector

Antenna Polarization

THAICOM PLC & IPSTAR Co., Ltd. Proprietary& Confidential
What is polarization?
• Microwave is an Electro-magnetic wave
which are composed of electric and
magnetic fields.
• The direction of electric field is at 90 degree
with the direction of propagation, and it is
called Polarization.
• If the electric field is oriented in a plane, it
is called Linear Polarization.

Polarization Angle
• The direction of the electric field is
controlled by the orientation of the feed
horn waveguide in the antenna.
• The polarization angle can be changed by
rotating the feed horn.
• The blue color waveform represents the
electric field, and can be denoted as:
– Horizontal polarization or
– Vertical polarization

Polarization Alignment
• For better efficiency to transmit and receive
microwave signal, the transmit and receive
feed horns should be aligned to match each
other.
• If the feed horn do not align, the
polarization is not correctly set, and it
causes loss and interference to the transmit
and receive signal.

Cross-Polarized Signals
• A feed horn can transmit and receive signals in different polarization.
• This can double the satellite link capacity.
• However, if the two feed horns are not correctly aligned, the signals are lost at
the receiving feed horns.

Polarization of Signals from Satellite
• When a signal from satellite reaches the earth, the polarization angle is slightly
changed depending on the location of antenna on the earth due to the skew
angle of the wave when it comes to the earth’s surface.

Polarization Angle (POL )
For 0.84 m antenna : Rotate the reflector.
For 1.2 antenna : Rotate the feed assembly
0.84m
• Polarization is a way to orient transmission
signals a specific direction.
• IPSTAR uses linear polarization.
– UT Receive: Vertical
– UT Transmit: Horizontal
Note: Polarization of China and Indonesia’s shape
beam is vice versa.
Positive
POL angle
Negative
POL angle
1.2m

Adjusting POL Angle of 84cm Antenna
Skew Angle = 90 – POL Angle
• Loosen the (four) skew locking bolts until it’s
rotatable.
• Rotate the reflector until the indicator mark
on the reflector align with skew angle on
Az/El/Skew Cap Mount.
• Tighten skew locking bolts.
**DO NOT over tighten**

Adjusting POL Angle of 1.2m Antenna
• Loosen the (two) M6 x 16 mm Hex Head Bolts.
• Rotate the feed assembly according to the job order.
• Tighten M6 x 16 mm Hex Head Bolts.
**DO NOT over tighten**
Positive
POL angle
Negative
POL angle

Ref
-
+
+
-
Ref

(Positive Polarization Angle)
POL = 25.8°
Ref
+25.8°
POL = 0°
Ref
-
+

(Negative Polarization Angle)
POL = -35.8°
-35.8°
POL = 0°
+
-
Ref

Cable and Connectors

Refer to Document “Recommendation on Cable and Connector for IPSTAR UT
101001”
Engineering Recommended List
Cable Stripper Rotary RG6 Cable Stripper Rotary RG11
Compression Tool CX3 All SizeGF-UE-6

Two-way Splitters

Two-way Splitter Configuration
Power Pass
LNB
DC Block
IDU
IRD
Two-way splitter
freq range : 900-2150 MHz

Site Survey

Location of ODU :
Line of sight  Clear  Not Clear
Present and future obstacles  Exist  Not Exist
Interference Source  Exist  Not Exist
Antenna mounting location  Rigid  Not Rigid
Public safety  OK  Not OK
Location of IDU :
Ventilation  Good  Not Good
AC Power Outlet  Available  Not Available
Cable length to ODU  < 30m  between 30m to 60m
Facilities :
Grounding  Available  Not Available
Power backup and protection  Available  Not Available
Cable route and conduit  Check  Not Check
Survey Result Agreed by premise owner  Yes  No
Survey Checklist

UT Installation Tips

Before running IUAT program
Installer should strictly do the following steps.
1. Antenna pole must be perpendicular to the earth's surface.
2. Foundation must be stable.

Before running IUAT program (Continue)
3. Mounting cab must be perfectly attached with the antenna reflector.
All the nuts must be tightened.

4. After plugging mounting cab, it must be finely attached with the pole.
This should be finely attached and stable.

5. Pre-adjust polarization angle according to the installation job order.

6. Pre-adjust elevation angle according to the installation job order.
This example :
Elevation = 36o

7. Use compass to pre-align antenna to Azimuth angle according to the
installation job order.
Note: During IUAT process, don’t have to use compass to adjust azimuth angle.

While running IUAT program
1. In IUAT Step 4, Antenna alignment, only try to adjust azimuth angle first until the
received signal is found and TOLL Es/No is detected. Continue to scan for the
maximum TOLL Es/No in Azimuth direction.
Azimuth angle adjustment

While running IUAT program (Continue)
2. Adjust elevation angle in small step to obtain the maximum TOLL Es/No.
3. Then adjust Polarization angle using the procedure described earlier.

Grounding

1/20/2011 70
Grounding
TerminalBox
Grounding block
A
A
Section A-A
Terminal Box
Master Grounding
Point
Outdoor
Indoor

THAICOM PLC & IPSTAR Co., Ltd. Proprietary& Confidential1/20/2011 71
Grounding at Antenna Stand

Grounding Block

Grounding at Feed Assembly

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