Satellite Internet

Satellite Internet Forum.

Welcome, Guest.
Welcome to this satellite broadband discussion forum. Wherever you are and whatever your problem we are here to help each other. Connecting to the internet via satellite is not always easy but is critically important to those in remote places or with poor terrestrial infrastructure. Both service providers and customers are encouraged to contribute. If you are showing as 'Guest', please register at the bottom of this home page if you wish to contribute or ask question. Read the Forum rules.
      Satellite internet forum          
Pages: 1

L-band transmission on optical fibre. Advice please ?

(Read 1103 times)
ronj
Ex Member


Oct 27th, 2016 at 5:18pm  
We need to transport Lband signal. Our distance is ~96 km, but we don't know exactly line attenuation. Can any one recomend right EDFA we found this company's but we never tried there product before
multicom
http://www.multicominc.com/product-category/solutions/video-data-voice/fiber-opt...
olson-technology
http://www.olson-technology.com/edfa-dcm.html

Is there any preferences in down-converters from C & Ku bands?
Any recommendations 

Back to top
« Last Edit: Oct 27th, 2016 at 8:05pm by Admin1 »  
 
IP Logged
 
ronj
Ex Member


Reply #1 - Oct 27th, 2016 at 5:18pm  
Hello,
Need recommendation for the project, is there any preferences in down-converters from C & Ku bands to LBand

Please advise
Back to top
 
 
IP Logged
 
Admin1
YaBB Administrator
*****
Offline


Personal text from: Profile,
Options, Top line

Posts: 849
Reply #2 - Oct 27th, 2016 at 8:07pm  
To down convert from C band or Ku band to L band use a Low Noise Block Downconverter (LNB). If frequency accuracy is important use the Phase Lock Loop (PLL) variety. The  most accurate results are obtained with an external 10 MHz reference from indoor reference oscillator based on GPS or Rubidium. The 10 MHz signal is sent up the cable to the LNB, along with DC power.

Regarding the design of RF over optical fibre links this is good reading:
RF-and-Microwave-Fiber-Optic-Design-Guide

Best regards, Eric.

Back to top
 
WWW  
IP Logged
 
ronj
Ex Member


Reply #3 - Oct 28th, 2016 at 1:39am  
Could you please recommend down-converter from C & Ku bands to LBand, which brand you would go with ?

Look forward to your reply
Back to top
 
 
IP Logged
 
Admin1
YaBB Administrator
*****
Offline


Personal text from: Profile,
Options, Top line

Posts: 849
Reply #4 - Oct 28th, 2016 at 1:18pm  
First, I would consider the least expensive solution and that is to use a conventional LNB directly connected to the antenna feed.

There are considerations of dual polarisation and, in the case of Ku band, upper and lower parts of Ku band. What do you want to receive ?
Some Ku LNBs have multiple outputs. For example low band vertical, low band horizontal, high band vertical and high band horizontal.
Some LNBs have a 'stacking' feature and merge outputs from two different input polarisations.  It all depends on what you want to do. If you are sending all signals via fibre then multiplexing the signals will reduce the number of fibres.
Is frequency stability/accuracy important? If so, use PLL type LNBs.

If you intend to use wide band LNAs followed by indoor  block down converters then read here:

http://www.norsat.com/solutions/microwave-products/bdc-ku-band/

http://www.norsat.com/wp-content/uploads/1000_bdc1.pdf

http://www.norsat.com/solutions/microwave-products/bdc-c-band/

http://www.norsat.com/wp-content/uploads/3000_bdc.pdf

These units have coaxial cable input, and are not low-noise devices. They are intended to be installed following a wide band LNA and, typically, a splitter.

Best regards, Eric
Back to top
« Last Edit: Oct 28th, 2016 at 6:03pm by Admin1 »  
WWW  
IP Logged
 
ronj
Ex Member


Reply #5 - Oct 28th, 2016 at 6:37pm  
Thank you for your help, we will contact norsat.

Ron
Back to top
 
 
IP Logged
 
Pages: 1