<Mike25226>
hmmmm... Do you think researching/making an amplifier would be a better option since, like you said, PCB antennas are fairly standard
<whitequark>
no
<whitequark>
these are commodity hardware
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<Mike25226>
Not sure I'm following. If the design is fairly standard... how else can you improve such an antenna, if not with some sort of amplifier
<whitequark>
what exactly do you want to achieve
<Mike25226>
better range
<Mike25226>
as well as good signal level
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<whitequark>
and you want an omnidirectional antenna with an amplifier?
<Mike25226>
yeah
<whitequark>
pointless
<whitequark>
and illegal, too
<whitequark>
pointless because signal drops off as 1/r^2 (for a more powerful transmitter), in addition to receiver picking up garbage on the same channel from afar (for a more sensitive receiver)
<whitequark>
you could a) use a directional antenna b) set up a network out of several routers
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<Mike25226>
Inverse square law?
<whitequark>
yes
<DocScrutinizer05>
generally an antenna with good gain would help. Hardly feasible as PCB antenna though
<DocScrutinizer05>
decen ground plane antenna has quite a bit of gain from 2D (omni)directional
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<DocScrutinizer05>
however will fail when you want to go vertical between AP and client
<DocScrutinizer05>
I.E. a ground plane antenna in attic is rather contraproductive for clients inhouse "under" the antenna
<DocScrutinizer05>
use MIMO
<DocScrutinizer05>
it basically acts like an adaptive virtual directional antenna
<Mike25226>
hmmm
<Mike25226>
MIMO is a multiple antenna design right?
<Mike25226>
watching a disassembly video to verify
<whitequark>
crack it oopen
<DocScrutinizer05>
wMIMO only makes sense with multiple physically distinct antennas. When your laptop only has one, it can't do MIMO
<DocScrutinizer05>
-w
<DocScrutinizer05>
conecting both antenna jacks of a mimo card to same antenna is contraproductive
<Mike25226>
I've opened it before, and was 90% certain it only had one (twice actually). But I always feel the need to assure myself when i have the smallest bit of doubt. Guess you could say I lack confidence
<Mike25226>
only has one
<DocScrutinizer05>
which btw is the reason to call one "main" and one "aux". The "aux" is the one to leave unconnected when only one antenna is used
<Mike25226>
Can a PCB antenna act as 2?
<DocScrutinizer05>
the card will (either automatically or by config) shut down the "aux" antenna and use only one
<Mike25226>
I imagine that would cause issues being that close
<DocScrutinizer05>
no, no antenna can act "as 2"
<Mike25226>
well, with a PCB... couldn't it be done?
<DocScrutinizer05>
sorry?
<Mike25226>
just tracing on back and front of PCB
<DocScrutinizer05>
that's two antennas, not one
<DocScrutinizer05>
however you must keep the antenna area clear of all conducting objects and traces, also of a second antenna
<DocScrutinizer05>
IOW one antenna per dedicated area
<Mike25226>
Figure 2 is what I am thinking I can do. Figure 3..... I doubt
<DocScrutinizer05>
figure1 is BS, done by somebody with no clue about RF basics. Figure2 is the standard setup. Fig3 is obscure, no idea what it means
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<DocScrutinizer05>
adamnt rule of RF: one connector, one cable, one antenna
<DocScrutinizer05>
you cannot do Y-cables
<Mike25226>
hmmm... then lenovo really messed up.... which might explain why my signal isn't better
<DocScrutinizer05>
you could add a band splitter to attach two antennas (one 2.4, one 5GHz) to one antenna input. Which would indeed look like fig3 then
<DocScrutinizer05>
ech of the "small PCB" in fig3 would need to be a band splitter then, basically a special filter that routes 2.4GHz signals to and from one antenna and 5GHz signal to and from the other
<DocScrutinizer05>
and of course this only makes sense when the antennas are actually made for only one band and can't handle the other
<Mike25226>
would that be better? (I could be wrong, but it would then use a different antenna when probing/scanning for networks while connected to a network)
<DocScrutinizer05>
no, that's not exactly how it works
<Mike25226>
do cards only probe when requested to do so?
<DocScrutinizer05>
the "advantage" is that the antennas get the signal they can handle.
<DocScrutinizer05>
for the antenna it's irrelevant if the card is "probing" or talking or listening
<Mike25226>
Is proximity of the 2.4GHz and 5GHz antennas important? Should they be some what distanced?
<DocScrutinizer05>
do you even have 2.4 and 5GHz antennas?
<DocScrutinizer05>
look, I'm not looking forward to discussing all possible permutations of configuring a multiband MIMO system, with all the gotchas this introduces
<DocScrutinizer05>
when your PC has ony one antenna, connect it to "main" and leave "aux" open. When it actually has 2 antennas, you connect one to "main" and one to "aux"
<DocScrutinizer05>
antenna *design* is an art rather than a science. Some even say it's voodoo
<Mike25226>
I plan to purchase 2 new antennas
<Mike25226>
or make them myself for fun
<DocScrutinizer05>
and where do you plan to place those?
<DocScrutinizer05>
mind you, they need to stay away a few cm from *all* conductive materials
<DocScrutinizer05>
even isolated ones
<whitequark>
my laptop somehow fares fine despite a solid aluminium lid
<whitequark>
with the antennas at the very bottom of the screen
<DocScrutinizer05>
well, when you *know* what you're doing, you can even integrate the antenna into the aluminium case
<DocScrutinizer05>
but then user MUST NOT "hold it wrong" X-P
<DocScrutinizer05>
the joy of doing RF tests in freefield, without anything resembling sth annoying like a user's hand ;-)
<DocScrutinizer05>
"the device works perfectly, unless a planet is near"
<DocScrutinizer05>
on a more honest less funny comment: you _can_ design antennas so they work near conducting surfaces. Actually a groundplane is exactly such a design. But you need to know your RF voodoo for that
<Mike25226>
I plan to place the antennas flat down on both sides of the keyboard
<DocScrutinizer05>
I guess that's about the worst place for antennas you could possibly find in a laptop
<Mike25226>
that's where lenovo placed the one antenna lol
<DocScrutinizer05>
assuming the kbd has an alu or steel base, and below the antennas would be main PCB, right?
<Mike25226>
screen casing is metal
<DocScrutinizer05>
see above
<DocScrutinizer05>
on a more honest less funny comment: you _can_ design antennas so they work near conducting surfaces. Actually a groundplane is exactly such a design. But you need to know your RF voodoo for that
<DocScrutinizer05>
sorry there's no simple answer to your problem
<DocScrutinizer05>
odds are whatever you implement DIY in good failth will be inferior than what lenovo implemented
<DocScrutinizer05>
so all I can recommend is: get the original service manual for your laptop and check what the manufacturer says how antenna is placed and built and how it shall get connected
<DocScrutinizer05>
compare to what you got, and fix any weird "improvements" somebody might have applied (is this a laptop you bought used? was the WLAN card retrofitted by a cheap cheesy repair shop?)
<Mike25226>
well, like I said, they use one antenna (or single small PCB). It is oriented horizontally (flat) to the right of the keyboard
<Mike25226>
Whole body is aluminum except the surface with touchpad and keyboard
<DocScrutinizer05>
that's all pretty fine but not sufficient info for me to recommend anything better than I already did
<DocScrutinizer05>
"there's a small PCB and two cables come from that" is no info an EE can use to give any recommendations
<DocScrutinizer05>
for all I know the "small PCB" might even have TWO antennas on it
<DocScrutinizer05>
impossible to tell from the available info
<DocScrutinizer05>
and "to the right of the keyboard" is not identical to what I understood when you said "flat down on both sides of the keyboard"
<DocScrutinizer05>
I understood that as "under the kbd" not as "to the right/left of the kbd"
<Mike25226>
Guess I'll just experiment and test. First like my figure 2 diagram, and then figure 3 after I do some research, using splitters like you said (for fig 3),
<Mike25226>
it's to the right of the kbd
<Mike25226>
not under the kbd
<DocScrutinizer05>
figure3 would only make sense when you had dedicated singleband antennas. Why would you want to do that? it's an inferior solution to a multiband antenna
<Mike25226>
Btw, thanks for your help. Really appreciate it, and I am learning some things I did not know before
<DocScrutinizer05>
and excuse when I'm wrong here, but to me it seems you didn't understand what's a band splitter
<DocScrutinizer05>
so your "small PCB" in fig3 is pretty unspecific
<Mike25226>
Oh, I was under the impression it was advantageous to have them separated
<DocScrutinizer05>
no it isn't
<DocScrutinizer05>
sorry afk, busy
<Mike25226>
k, thanks again for the help
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<DocScrutinizer05>
he's gone, nevertheless prolly the term "band splitter" isn't exactly to the point, rather "frequency-separating filter" or "crossover"
<DocScrutinizer05>
or diplexer
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<wpwrak>
kristianpaul: hmm no, didn't need to make any mini-VMs yet :)