indoor mobile signal improvement

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kripacharya

kripacharya

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My indoor signal strenght drops to zero at some places inside my house.

So i'm thinking - what if I make a resonant Quad antenna and stick it on the roof, and another resonant quad and place it indoors, and connect the two with a good co-ax with maybe a matching (passive) network.

Would that help getting better signal indoors ?
 

Yes of course ... a passive (hence simplistic) bidirectional repeater.
This is not for WiFi (~2.4Ghz) but for the 900Mhz GSM band which would yield a quad of ~3.3" square, and hence quite compact & sturdy in itself.
I didn't realise that quads were only good at below 50Mhz !!?

Thanks for the url's, they helped. Anything further advise of a practical nature would be great !
 

Some simplified math. Roof antenna gain +10 dB, cable loss 5 dB, indoor antenna gain +10 dB, total gain +15 dB. Transmission loss between indoor antenna and cellphone antenna ~20 dB at 1 meter distance. Remaining gain -5 dB.
Yes it will work with quad antennas, but a bit small indoor coverage.
 

The issue here is to somehow get some signal into the indoor space, which otherwise has virtually no signal - or at least too weak for the 'phone to use.

Now I am assuming that the signal loss is due to masonry/ concrete/ steel /etc whose attenuation is definitely greater than a co-ax. Hence anything which can help the signal get in/out would be useful.

The trick is in finding a viable & practical solution.

So as Kafeman calculated, if I can get a signal indoors which is only 5dB down, then even that would be better than a signal which is otherwise possibly (say) 20 dB down ?
Thats a gain of +15dBindoor

you see what I'm saying ?
 

Yes it is correct, the signal would in my calculation be 5 dB below the outdoor signal. It is a somewhat optimistic calculation as a gain also is assumed for the indoor antenna, but at 1 meter distance would directive gain just a few dB as it is near field.
It also assumes that the antennas are very well tuned and matched for a gain of 10 dBi. Cable loss, including connectors, was assumed.
Losses in indoor antenna can be reduced by connecting phone directly to the coaxial cable or connect by a passive coupler and let a Bluetooth headset handle the indoor coverage.
 

So if i make a folded-dipole Yagi, or maybe a dipole-fed parabolic with a matched cable (RG58 ?) using a 1/2 wave phase shifter co-ax or a 1:4 balun (for the folded dipole that is, not the simple dipole).

I'm thinking a 11- 12 element yagi giving a gain of (hopefully) 12- 14dbd, and an aperture of around 30deg.
haven't done the calcs for the parabolic, tho' that will be much more compact at least.

Then i take this rg58 down & inside, and connect it to a low gain monopole above a virtual ground-plane - a large blank pcb basically.

would that do the job of a nice passive repeater ? all dimensions of course tailored to 900MHz GSM band which is the most popular used here.

Or am i missing something ?
 

E.Kafeman said:
Losses in indoor antenna can be reduced by connecting phone directly to the coaxial cable or connect by a passive coupler and let a Bluetooth headset handle the indoor coverage
Click to expand...

That there alone is by far the best suggestion!!

Dave
 

davenn said:
That there alone is by far the best suggestion!!

Dave
Click to expand...

only if you actually use a bluetooth.

So no one has ANY experience, or any practical advise about such a setup ?
 

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