Anyone has done a Comparison GTA02 GPS Antenna vs. Nokia N95?

Al Johnson openmoko at mazikeen.demon.co.uk
Mon Dec 5 17:35:24 CET 2011


On Monday 05 December 2011, Dr. H. Nikolaus Schaller wrote:
> Hi,
> 
> Am 05.12.2011 um 15:51 schrieb rakshat hooja:
> > On Mon, Dec 5, 2011 at 2:44 PM, Dr. H. Nikolaus Schaller
> > <hns at goldelico.com> wrote: We have seen that the N95 has a quite simple
> > flexible PCB GPS antenna instead of the ceramic
> > patch of the GTA0*. Does anyone of you own
> > both, a N95 and GTA0*?
> > 
> > 
> > I have a N95 and a few GTA02s. Let me know what exactly do you want me to
> > test re GPS?
> 
> Great!
> 
> Do you have some software for both that shows the
> satellite positions and (relative) signal strength?
> 
> What will be interesting is if the GTA02 sees the satellites
> more uniform.
> 
> The background is that the ceramic patch antenna in the
> GTA02/04 should have a more omnidirectional sensitivity
> while the N95 has just one flexible PCB with a long wire.

?! Would that actually provide enough signal to get a lock without assistance? 
I ask partly because it may explain why a friend couldn't get a gps lock on an 
N95 when on deck on a yacht out of range of mobile networks. GTA02 was 
reliably coldstarting in ~40s as you'd expect with a clear sky view like that. 
You need significantly better signal to get the initial fix than to maintain 
it, as we found with the SD drive strength issue.

> And the latter should show some clear direction sensitivity.
> 
> I.e. if the device is rotated some satellites should
> become weaker and others stronger.
> 
> So far the theory we want to probe :)
> 
> If the N95 antenna does not show such effects, we
> may have a cheaper approach for future GTA04 variants.
> And they may be more easily integrated into new cases
> than the 15x15mm ceramic block...

Have you looked at an antenna like this? Smaller, cheaper and lower 
performance than a patch antenna, but probably significantly better than a 
wire.
https://www.sparkfun.com/products/9131

> Many thanks for any results,
> Nikolaus




More information about the community mailing list