1. No category

2003-05-19
How to choose the right LNB for the Ku-band QPSK
First you have to look at the Data rate, Symbol rate or Bandwidth to select the recommended LO
stability. Please note that all models can be used for higher rate or specified bandwidth.
Data rate
from 20 kbps
from 200 kbps
from 500 kbps
from 2 Mbps
from 3 Mbps
from 20 Mbps
from 30 Mbps
from 40 Mbps
from 60 Mbps
Recommended Model and LO Stability
PLL ext. 10 MHz ref. (LO stability depends on the external reference)
PLL LO stability +/- 10 kHz
PLL LO stability +/- 25 kHz
PLL LO stability +/-100 kHz
PLL LO stability +/-150 kHz
LNB with DRO oscillator LO stability +/- 1 MHz
LNB with DRO oscillator LO stability +/- 1.5 MHz
LNB with DRO oscillator LO stability +/- 2 MHz
LNB with DRO oscillator LO stability +/- 3 MHz
Symbol rate
from 10 kSamples/s
from 100 kSamples/s
from 250 kSamples/s
from 1 MSamples/s
from 1.5 MSamples/s
from 10 MSamples/s
from 15 MSamples/s
from 20 MSamples/s
from 30 MSamples/s
Recommended Model and LO Stability
PLL ext. 10 MHz ref. (LO stability depends on the external reference)
PLL LO stability +/- 10 kHz
PLL LO stability +/- 25 kHz
PLL LO stability +/-100 kHz
PLL LO stability +/-150 kHz
LNB with DRO oscillator LO stability +/- 1 MHz
LNB with DRO oscillator LO stability +/- 1.5 MHz
LNB with DRO oscillator LO stability +/- 2 MHz
LNB with DRO oscillator LO stability +/- 3 MHz
Bandwidth
from 10 kHz
from 100 kHz
from 250 kHz
from 1 MHz
from 1.5 MHz
from 10 MHz
from 15 MHz
from 20 MHz
from 30 MHz
Recommended Model and LO Stability
PLL ext. 10 MHz ref. (LO stability depends on the external reference)
PLL LO stability +/- 10 kHz
PLL LO stability +/- 25 kHz
PLL LO stability +/-100 kHz
PLL LO stability +/-150 kHz
LNB with DRO oscillator LO stability +/- 1 MHz
LNB with DRO oscillator LO stability +/- 1.5 MHz
LNB with DRO oscillator LO stability +/- 2 MHz
LNB with DRO oscillator LO stability +/- 3 MHz
The Phase noise and Noise figure.
All SMW models has low Phase noise and Noise Figure, and are not neccessary to select for the
LNB. Please look in the specifications.
Secondly you have to look at the Gain. The figures are general and may vary depending on how
strong the signals are.
Size of the dish
up to 3.0 m
3.4 m
3.8 m
4.5 m
5.0 m
6.3 m
6.3 m
7.2 m
8.1 m
9.3 m
9.3 m
11 m
13 m
Gain (guideline value)
Standard gain
Max 50 dB
Max 48 dB
Max 47 dB
Max 47 dB
Max 44 dB
Max 44 dB
Max 43 dB
Max 42 dB
Max 41 dB
Max 41 dB
Max 40 dB
Max 38 dB
If you have any questions you are very welcome to contact us at:
SMW AB
Box 230
591 23 MOTALA, SWEDEN
Tel. +46 141 21 61 35
Fax. +46 141 21 52 24
e-mail: info@smw.se
Website: http://www.smw.se