Add an antenna to a D-Link DWA-643 ExpressCard?

Does anyony know how I could add an antenna to a D-Link DWA-643
ExpressCard.

Here is a pic:
http://i42.tinypic.com/295za8g.jpg

It's a wireless N card.
I've noticed other people adding antennas to their cardbus cards
havent found anything on wireless N though.
Trying to somehow attach an mc/mmcx connector somehow.

Any help would be appreciated.

Thanks

On Wed, 11 Feb 2009 15:44:57 -0800 (PST), terminator129@gmail.com
wrote:

>Does anyony know how I could add an antenna to a D-Link DWA-643
>ExpressCard.
>
>Here is a pic:
>http://i42.tinypic.com/295za8g.jpg

Nice photo. The connectors are test connectors and are either Hirose
u.FL or I.PAX MHF connectors. It's difficult to tell without a better
view.
<http://groups.google.com/group/alt.internet.wireless/msg/44d94c76db3231a5>


>It's a wireless N card.

That's a problem. External antennas and MIMO don't work. You can do
it if you maintain the approximate spacing and directionality of the
original antennas, but that's difficult. However, if you don't care
about MIMO and just want more range instead of more speed, just
disable MIMO (802.11n) features in the driver settings, attach *ONE*
antenna pigtail to an external antenna, and it should work. Deciding
which antenna is the "main" and which is the "aux" is a problem. Trial
and error (or an oscilloscope on the PIN diode switch) should help.

Another problem is that the original antennas will get in the way.
Just plugging an external antenna is not going magically disable the
internal antennas. They'll still radiate with some of the RF going to
the external antenna, and some of it going to the internal antennas.

Also, the internal connectors are made for production line testing,
not user interface. The connectors are good for only a few insertions
before falling apart. There's no retaining or locking mechanism. I
use hot melt glue.

>I've noticed other people adding antennas to their cardbus cards
>havent found anything on wireless N though.

For good reason. Need a detailed explanation?

>Trying to somehow attach an mc/mmcx connector somehow.

Bah. Solder a pigtail to the board with an SMA or bigger on the end.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl@comix.santa-cruz.ca.us
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

Thanks for your reply Jeff.

Here is a higher resolution pic:
http://i44.tinypic.com/281to5j.jpg

I'm not sure what type of connector they are; doesn't seem as if you
can connect anything to them. Definitely not Hirose connectors, there
is no pin in the center, just a hole.

Speed is not a big issue, all I have is a G router.
Do you think this will work:
I disable the original antenna by removing the capacitors C51 & C107.
Solder the pigtail to end of J4 (or L24) and connect J4 to J6 (or
L24).
If that doesn't work try connecting separately, test results.
How can you determine if you require reverse polarity? I assume if I
use an N connector it souldn't matter SMA does?

Thanks again.

On Thu, 12 Feb 2009 05:20:55 -0800 (PST), terminator129@gmail.com
wrote:

>Thanks for your reply Jeff.
>
>Here is a higher resolution pic:
>http://i44.tinypic.com/281to5j.jpg

It's an MS-156:
<http://www.seattlewireless.net/MS-156>
Data sheet:
<http://www.hirose.co.jp/cataloge_hp/e35801678.pdf>
The receptacle is actually a switch. Push on the center "plate" and
it disconnects the antenna and makes an RF connection to the jack. The
jack does NOT have to be connical shaped for this to work.

Incidentally, this is the offical MS-156 to SMA adapter drawings:
<http://www.hirose.co.jp/cataloge_hp/e30000006.pdf>

>Speed is not a big issue, all I have is a G router.

Ok.

>Do you think this will work:
>I disable the original antenna by removing the capacitors C51 & C107.
>Solder the pigtail to end of J4 (or L24) and connect J4 to J6 (or
>L24).
>If that doesn't work try connecting separately, test results.

Maybe. I don't want to speculate. What I think might be better is to
just unsolder both antennas from the board. The solder pads are HUGE
and easy to attach a pigtail or connector (with VERY VERY VERY short
leads). It kinda looks like the antennas are both PIFA type, which
has 3 connections. One is ground, which should be obvious. The 50
ohm feed point is nearest the ground end and goes to the string of
small parts that eventually go over to the test jacks. The 3rd end
goes nowhere is usually just soldered to a pad for mechanical support.
One nice thing about doing it this way is that you don't destroy the
board or remove any parts. It's also easily reversable.

>How can you determine if you require reverse polarity?

Reverse polarity what? The connector? Presumably, you have some
connector in mind that's attached to a coax cable or antenna. There's
no way for me to guess which antenna you plan to use. However, if you
have a coax cable involved, type N is probably best. If you're going
directly to an antenna, RP-TNC or RP-SMA. If you're playing with test
equipment, have a pile of adapters, or wanna mount it on a bracket,
SMA female is probably the easiest. You're choice.

>I assume if I
>use an N connector it souldn't matter SMA does?

Doesn't matter. The only thing that's important is that the leads are
extremely short, with no exposed center conductor.

Note that without a mess of RF test equipment, it's going to be
difficult to determine which derrangement or hardware works best.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl@comix.santa-cruz.ca.us
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

On 12/02/2009 01:59, Jeff Liebermann wrote:
> On Wed, 11 Feb 2009 15:44:57 -0800 (PST), terminator129@gmail.com
> wrote:
>
>> Does anyony know how I could add an antenna to a D-Link DWA-643
>> ExpressCard.
>>
>> Here is a pic:
>> http://i42.tinypic.com/295za8g.jpg
>
> Nice photo. The connectors are test connectors and are either Hirose
> u.FL or I.PAX MHF connectors. It's difficult to tell without a better
> view.
> <http://groups.google.com/group/alt.internet.wireless/msg/44d94c76db3231a5>
>
>
>> It's a wireless N card.
>
> That's a problem. External antennas and MIMO don't work. You can do
> it if you maintain the approximate spacing and directionality of the
> original antennas, but that's difficult. However, if you don't care
> about MIMO and just want more range instead of more speed, just
> disable MIMO (802.11n) features in the driver settings, attach *ONE*
> antenna pigtail to an external antenna, and it should work. Deciding
> which antenna is the "main" and which is the "aux" is a problem. Trial
> and error (or an oscilloscope on the PIN diode switch) should help.

I have not seen any info as to how these type of units work when they
operate in non-n mode. In the case of a 2x2 system do they actually
disable one of the radios or do they reduce the throughput through both
radios?
The operational description on the FCC website is pathetic.
"This device is a D-Link DWA-643 Xtreme NTM ExpressCard Notebook
Adapter, which operates in the 2.4GHz frequency spectrum with throughput
of up to 300Mbps which OFDM technique will be applied. If the signal to
noise radio is too poor which could not support 300Mbps, the 11Mbps data
rate with DSSS technique will be applied.The transmitter of the EUT is
powered by host equipment. The antenna is PIFA antenna without antenna
connector."
The FCC ID is KA2WA643A1 if you want to look at their photos.

Thanks again Jeff.
I'll start destroying and see what I get out of it.
BTW I love your Salad-Dish!!!!!!

On Fri, 13 Feb 2009 05:49:51 -0800 (PST), terminator129@gmail.com
wrote:

>Thanks again Jeff.
>I'll start destroying and see what I get out of it.
>BTW I love your Salad-Dish!!!!!!

Ummm... It sorta works, but not very well. The basic idea was to add
some gain to junk USB radios and Wi-Spy dongles. The salad bowl is
NOT parabolic. When illuminated with a light bulb at the focus, the
resultant pattern is a annular ring with a hole in the center. Not
exactly an ideal pattern but certainly better than the USB dongle
alone. Check the pattern optically before destroying the salad bowl.

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 13 Feb 2009 10:45:44 +0000, LR <lrme@privacy.net> wrote:

>On 12/02/2009 01:59, Jeff Liebermann wrote:
>> That's a problem. External antennas and MIMO don't work. You can do
>> it if you maintain the approximate spacing and directionality of the
>> original antennas, but that's difficult. However, if you don't care
>> about MIMO and just want more range instead of more speed, just
>> disable MIMO (802.11n) features in the driver settings, attach *ONE*
>> antenna pigtail to an external antenna, and it should work. Deciding
>> which antenna is the "main" and which is the "aux" is a problem. Trial
>> and error (or an oscilloscope on the PIN diode switch) should help.

>I have not seen any info as to how these type of units work when they
>operate in non-n mode. In the case of a 2x2 system do they actually
>disable one of the radios or do they reduce the throughput through both
>radios?

Nope. It switched to diversity receive mode, exactly the same as in
an ordinary 802.11g adapter. See clues buried in the Ruckus docs at:
<http://www.netgear.com/upload/solutions/rangemax/enUS_pdf_whitepaper_RangeMax.pdf>
"When the SM (spatial mux) mode is not possible, a MIMO system reverts
to diversity mode."

Extra credit if you can guess which antenna is "Main" and "Aux" in
diversity mode. Sigh...

>The operational description on the FCC website is pathetic.
>"This device is a D-Link DWA-643 Xtreme NTM ExpressCard Notebook
>Adapter, which operates in the 2.4GHz frequency spectrum with throughput
>of up to 300Mbps which OFDM technique will be applied. If the signal to
>noise radio is too poor which could not support 300Mbps, the 11Mbps data
>rate with DSSS technique will be applied.The transmitter of the EUT is
>powered by host equipment. The antenna is PIFA antenna without antenna
>connector."

The description is primarily to satisfy operational requirements and
specs detailed in 15.247. I've been told that less detail is best as
it doesn't give the FCC anything to complain about.

>The FCC ID is KA2WA643A1 if you want to look at their photos.


--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558 jeffl@comix.santa-cruz.ca.us
# http://802.11junk.com jeffl@cruzio.com
# http://www.LearnByDestroying.com AE6KS

On 13/02/2009 22:20, Jeff Liebermann wrote:

>> I have not seen any info as to how these type of units work when they
>> operate in non-n mode. In the case of a 2x2 system do they actually
>> disable one of the radios or do they reduce the throughput through both
>> radios?
>
> Nope. It switched to diversity receive mode, exactly the same as in
> an ordinary 802.11g adapter. See clues buried in the Ruckus docs at:
> <http://www.netgear.com/upload/solutions/rangemax/enUS_pdf_whitepaper_RangeMax.pdf>
> "When the SM (spatial mux) mode is not possible, a MIMO system reverts
> to diversity mode."
>
> Extra credit if you can guess which antenna is "Main" and "Aux" in
> diversity mode. Sigh...
I don't really like their explanation as all the examples quoted are
using diversity techniques, manufacturers seem to like referring to
diversity in MIMO as more antennas.
"Without doubt,the performance of MIMO systems improves with additional
diversity (i.e.,more
antennas).<http://www.atheros-xspan.com/modules/articles/files/MIMO_Pwr3_whitepaper.pdf>
In the early examples, from the netgear pdf, they have added an extra
Rx to give Rx diversity and in their 2x2 example they are using a
diversity combiner. I don't think they will have a "Main" and "Aux"
antenna system as it is possible they are using MRC and you get the
combined result.
"In contrast, switched diversity and Maximum Ratio Combining are
diversity techniques that can be implemented on just one side of a
communications link; therefore they can benefit all existing
802.11a/b/g devices."