[ath9k-devel] AR9223 with 3 antennas

[ath9k-devel] AR9223 with 3 antennas

[Luis R. Rodriguez]

On Wed, Aug 18, 2010 at 07:44:43AM -0700, Jan Friedrich wrote:
> Hello Luis,

Please send these type of questions to the mailing list.

> At my working place (University of Leipzig, Germany) we use PCI-Cards
> with the AR9223 chip (D-Link DWA-547) that feature 3 antennas each. As
> far as I know the AR9223 is the same as the AR9220 but supports only
> 2.4GHz. And the AR9220 is somehow identical to the AR9280 which supports
> 2x2 MIMO.
> 
> My simple question: is the third antenna in any way used by the Atheros
> AR9223 or has there to be some vendor-specific circuit on the card that
> uses the third one? (There is no such thing as a datasheet for the
> AR9223 publicly available, isn't there?)

Its a 3x2 card, see the "Spatial Stream" section on this page:

http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n#Spatial_streams

So for this card 3 antennas are available, two antennas are dedicated
to one chain with selection diversity.

  Luis

[ath9k-devel] AR9223 with 3 antennas

[David Quan]

this designs is a custom design.

AR92xx only supports max of 2 spatial streams. Adding more antenna does not change that.
So with the 3rd antenna, the customer just added diversity to only one of dedicated TX/RX path.
 

-----Original Message-----
From: Luis Rodriguez 
Sent: Wednesday, August 18, 2010 10:23 AM
To: Jan Friedrich
Cc: Luis Rodriguez; David Quan; ath9k-devel at lists.ath9k.org
Subject: Re: AR9223 with 3 antennas

On Wed, Aug 18, 2010 at 07:44:43AM -0700, Jan Friedrich wrote:
> Hello Luis,

Please send these type of questions to the mailing list.

> At my working place (University of Leipzig, Germany) we use PCI-Cards
> with the AR9223 chip (D-Link DWA-547) that feature 3 antennas each. As
> far as I know the AR9223 is the same as the AR9220 but supports only
> 2.4GHz. And the AR9220 is somehow identical to the AR9280 which supports
> 2x2 MIMO.
> 
> My simple question: is the third antenna in any way used by the Atheros
> AR9223 or has there to be some vendor-specific circuit on the card that
> uses the third one? (There is no such thing as a datasheet for the
> AR9223 publicly available, isn't there?)

Its a 3x2 card, see the "Spatial Stream" section on this page:

http://wireless.kernel.org/en/developers/Documentation/ieee80211/802.11n#Spatial_streams

So for this card 3 antennas are available, two antennas are dedicated
to one chain with selection diversity.

  Luis