Splitting GPS

[Keiser]

Here's the scenario:
I want to insert a splitter in the cable coming from the GPS antenna and connect it to multiple GPS receivers I obviously get a loss here, but compensate for this loss, would an LNA suffice without injecting too much noise? If the LNA compensated for the loss, let's say 10 dB, roughly how much of a hit in C/I would I see (in dB).

thanks,

-k

 

[Lewish]

I don't recognise the term C/I. But to try to answer the rest of the question, a very low noise LNA would do what you want. Quality of cabling and quality of the LNA and quality of the splitter would be the issues. If you split the signal in half to feed two receivers, each receiver would get -3dB less signal than without a splitter, assuming no loss in the splitter itself. Most good two-way splitters have about a -2dB insertion loss at GPS frequencies. Don't try to use a TV splitter. Too lossy and too noisy.
If you split 3 ways your loss becomes -5dB, four ways -6 dB and 5 ways -7dB. Those numbers are at each reciever plus your insertion loss.

Hope this helps.

Lewis

 

[Keiser]

thanx Lewis! that pretty much confirms what I was thinking. I found a company, gpssource that has some good splitters with LNA's in them, so I'll probably go with those.

btw, C/I = Carrier to Interference ratio

thanks for the info

-k