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Message started by ronj on Oct 27th, 2016 at 5:18pm

Title: L-band transmission on optical fibre. Advice please ?
Post by ronj on 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-optics/rf-broadband/edfa/?gclid=CIHtg6qu-88CFQQ0aQod0VQH9g
olson-technology
http://www.olson-technology.com/edfa-dcm.html

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


Title: Down-converters from C & Ku bands to Lband
Post by ronj on 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

Title: Re: L-band transmission on optical fibre. Advice please ?
Post by Admin1 on 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.


Title: Re: L-band transmission on optical fibre. Advice please ?
Post by ronj on 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

Title: Re: L-band transmission on optical fibre. Advice please ?
Post by Admin1 on 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

Title: Re: L-band transmission on optical fibre. Advice please ?
Post by ronj on Oct 28th, 2016 at 6:37pm
Thank you for your help, we will contact norsat.

Ron

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