ut installation review

IPSTAR User Terminal Installation Review

IPSTAR Training Department

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Skynet MPS Setup

TX cable (RG-11)

RX cable (RG-6, RG-11)

ATA

Two-way splitterIRD

Rx attn

Tx attn

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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.

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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


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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

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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

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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 TypeKu-Band

Frequency (GHz)

L-BandFrequency

(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 *

BroadcastBeams

11.5 – 11.7 1850 – 2050 9.65 GHz Vertical

* Except China and Indonesia’s shaped beams use Horizontal

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Block Diagram of BUC

• BUC uses internal LO for frequency up conversion.

• BUC amplifies the signal with SSPA (Solid State Power Amplifier).

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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 TypeKu-Band

Frequency (GHz)

L-BandFrequency

(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

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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

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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.

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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

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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

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User Terminal Block Diagram

Ku-bandL- bandTransmit signal:

L-bandReceive signal: Ku-band

Antenna Reflector

Antenna


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IPSTAR Antenna

Reflector Size 0.84m 1.2m 1.8m

Picture

Antenna Type Offset Offset Offset

Reflector Materialmetal reflector with

rolled aluminum edge

Glass Fiber Reinforced

Polyester reflectorwith iron mesh

Glass Fiber Reinforced

Polyester reflectorwith 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 BeamwidthAt 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


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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.**

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5. Connect Feed Arm to the reflector 6. Set feed assembly initial position & Connect it to the feed support arm


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Liquid-filled Level3. Assemble AZ/EL/Skew Cap Mount

on reflector

4. Connect Reflector on pipe


**Refer to antenna assembly manual for more details.**

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Liquid-filled Level

1. AZ/EL Cap Mount 2. Assemble AZ/EL Cap Mount on reflector

1.2m Antenna Assembly

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Liquid-filled Level3. Connect Reflector on pipe 4. Side Feed Legs Installation


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5. Bottom Feed Leg Installation 6. Connect Feed Legs & Junction Block


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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 markon 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

Adjusting POL Angle of 1.2m Antenna

Ref

-

+

+

-Ref

Adjusting POL Angle of 1.2m Antenna(Positive Polarization Angle)

POL = 25.8°

Ref

+25.8°

POL = 0°

Ref

-

+

Adjusting POL Angle of 1.2m Antenna(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 Size GF-UE-6


Two-way Splitters


Two-way Splitter Configuration

Power Pass

LNB

DC Block

IDU

IRD

Two-way splitterfreq range : 900-2150 MHz

Site Survey


Location of ODU :

Line of sight Clear Not ClearPresent and future obstacles Exist Not ExistInterference Source Exist Not ExistAntenna mounting location Rigid Not RigidPublic safety OK Not OK

Location of IDU :

Ventilation Good Not GoodAC Power Outlet Available Not AvailableCable length to ODU < 30m between 30m to 60m

Facilities :

Grounding Available Not AvailablePower backup and protection Available Not AvailableCable 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


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Grounding

Terminal Box

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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