Increase WiFi signal... - Nexus 7 Q&A, Help & Troubleshooting

Bit of a shot in the dark, but wouldn't adding more metal (large surface area) between the WiFi pins and the antenna increase signal strength? Or is the antenna more than just some sort of metal?
Sent from my Nexus 7 using xda premium

Anyone??

I havent got a clue. But I AM curious if anyone knows...
Sent from my Nexus 7 using XDA Premium HD app

mattcooper said:
Bit of a shot in the dark, but wouldn't adding more metal (large surface area) between the WiFi pins and the antenna increase signal strength?
Click to expand...
Click to collapse
Perhaps (most likely not), but for sure you will make things a lot worse in at least a full half-hemisphere of angles.
mattcooper said:
Or is the antenna more than just some sort of metal?
Click to expand...
Click to collapse
Yes.
The gain and directivity of antennas depends critically on dimensions of all metallic structures (including the antenna itself) in the "near field" of the antenna. Even for simple omnidirectional "whip" antennas, the length of the whip determines the frequency band at which it will work the best. Randomly adding metal nearby will usually make things worse, or at a minimum change its directivity.
As an antenna is a passive structure, gain can only be achieved by improving it in one direction while simultaneously making it worse in more directions. But because the orientation of the tablet in relation to the WiFi router (or cell tower) can not be predicted in advance, a high-gain directional antenna can not be used - it is undesirable. This is exactly the reason that automobiles and boats do not use high gain antennas such as dish or Yagi antennas - they will be used in all orientations except perhaps upside-down. (But the tablet probably will be used while it's owner is lying down - an upside-down configuration.)
Don't get me wrong - all the metal in the tablet/handset does alter the antenna gain pattern, and some manufacturers do a better job than others in figuring out how to place a simple, low-gain antenna in their device (in relation to all the other components) so there are no (or few) "dead spots" in the antenna pattern, and that the "RF matching" between the radio chip and the antenna is correct.
Remember Apple's iPhone "You are holding it wrong!" PR fiasco? Immediately after that happened, Apple started hiring (more) antenna designers. They were already doing some of that sort of thing, and now they are doing even more of it.
To suggest that a hobbyist can modify things to improve their antenna design is the same thing as presuming that the handset/tablet designers are completely ignoring antenna design issues. I doubt that is the case.

Related

Cases blocking antennas????

Are the cases for our phones partially blocking signal strength on our Evo's antennas.... sorry if this is a bone head question....
Sent from my Supersonic EVO Using 4G Speeds
K-Driod said:
Are the cases for our phones partially blocking signal strength on our Evo's antennas.... sorry if this is a bone head question....
Sent from my Supersonic EVO Using 4G Speeds
Click to expand...
Click to collapse
Probably a little, I dont know by how much though.
If the pic in your sig is from your phone I don't think you have anything to worry about though. A 11ms ping is sick, I would love to have that when playing black ops.
Your signal would only be degraded if the case you are using is made of some sort of metal or has a high metal content.
Sent from my PC36100 using Tapatalk
Any object you put between an antenna and a transmitter will have some effect on signal strength. However, it's highly unlikely the little bit of plastic and/or rubber contained in a case will have enough effect that you will notice it unless your case is made of metal. Things like trees, hills, or being inside a building or a car will weaken your signal far more than putting a case on.
Sent from my HTC EVO 4G with Tapatalk
Actually, it is possible that a case could improve your signal slightly. The reason for that is that your body (hand holding the phone) being close to the antenna will attenuate the signal. The case gives you a little more space between your hand and the antenna, so the signal will be attenuated less. In reality, probably won't make a measurable difference either way.
kinda like how apples solution to antennagate was free cases..
Only case I had that used to mess with my signal was a aluminum case. Long time ago couldn't even remember which phone it was on
Sent from my Evo while i should be working

[Q] Reception, how to improve?

So, we have probably all noticed that even compared to other phones the xperia line (and the Play in specific) seem to suffer from lower reception capability.
Putting them side by side, my Motorola Droid (A855, OG Droid 1) gets a better signal both in DB measurement and in bars. Same thing for WiFi signal. I'm guessing there is an issue with design of the antenna array in the device that causes for lower reception/broadcast quality.
I don't wish to shell out $300 for a cell repeater or $300 + monthly for a femtocell that will eat my internet bandwidth (which is pathetically limited). With that in mind, I went and started looking over the device, its teardowns, and its schematics. I was looking for something as a diversity jack for an external antenna. Now I noticed, next to the battery connector, there is a small semi-covered coax input. It appears that if you pulled off the rest of the sticker, or even if you just pushed a coax prong into there you could potentially be an antenna. However, it is not specifically labeled as such on the system board or the chassis, and the schematics were largely electrical diagrams and not system board schematics. Is there any answer for this? On pretty much every smartphone I have ever owned, there is an auxillary or "diversity" coax jack for adding an external antenna or doing signal injection.
Does anybody have any input on this? I would love to be able to boost my phone's reception quality, even if only in the car or at home (even if it means a custom modded case for ease of connect/disconnect).
Cant help you with your specific question but i can throw a tip.
- Switch your phone to GSM only. It will strengthen the signal. The downside is you are stuck with G/E data speeds (slower than H).
dsswoosh said:
Cant help you with your specific question but i can throw a tip.
- Switch your phone to GSM only. It will strengthen the signal. The downside is you are stuck with G/E data speeds (slower than H).
Click to expand...
Click to collapse
Sadly, with the US-CDMA variant and its firmware, I believe that is not an option. I'm specifically using the R800x. However, the board layouts are essentially identical.
I don't see the problem if you arnt getting any dropped calls. Wrap your phone in tin foil lmao
Sent from my XPlay using XDA App.
Deoxlar said:
I don't see the problem if you arnt getting any dropped calls. Wrap your phone in tin foil lmao
Sent from my XPlay using XDA App.
Click to expand...
Click to collapse
Well that is sort of the problem. I live in an area that its hills are filled with lead and other heavy minerals. Dead zones and limited signal zones are rampant, especially while driving. I _DO_ get dropped calls, and more importantly dropped data. Heck I even get dropped data from the router in the house through only one wall just a room away.
Basically if I can find out where exactly the aux/diversity port is for antennas, then I could design and fabricate a better back cover to either allow for external antennas, or to integrate better antennas into the cover (like the Thunderbolt sort of does).
Side note: Wrapping it in Tin/Aluminum Foil would make it worse, I believe (yes I have limited sense of humour).
you can easely remove the rubber in front of the coax port (atleast it definitly looks like a coax port). Would like to see a back case with better antenna in it (also being able to harbor an extra fat battery).
svenk919 said:
you can easely remove the rubber in front of the coax port (atleast it definitly looks like a coax port). Would like to see a back case with better antenna in it (also being able to harbor an extra fat battery).
Click to expand...
Click to collapse
The problem is that there are several coax ports. The one near the battery connector is the most obvious, but there are some more that are under the secondary cover or behind more stickers. Trying to find out which one is which or what they do is not easy. I have some basic electronics schematics, some teardown pics/video, and a really really sparse parts replacement guide, but not much else to go on.
Plug in an antenna and see if it improves?
svenk919 said:
Plug in an antenna and see if it improves?
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Click to collapse
*laughs* I suppose that would be the easy/simple way to find out, wouldn't it?
I'll see if I can find a matching pigtail adapter and see if I can plug a big fat antenna into and see if the DBM improves for either Cell or WiFi. I wanted to see if anybody could confirm before I attempted to mod this thing.

Custom GPS antenna for THL W8 Beyond

Hey
I'd like to fix my crappy GPS antenna, can anyone here help me with that - I don't know how it looks like and don't know how to take the phone apart safely besides being careful not to yank the mic
Will only copper wire work?
Has anyone ever done this?
This device is notorious for it's bad GPS reception but there's not info on how to fix it and I'd sure appreciate any help.
Thanks in advance!
Software?
Hey, did you try some software changes, before you unassembly phone? I have an iOcean X7 Elite (same MTK chipset) and Uncletools with updated EPO was helpfull for me. Fix GPS max. 20 seconds. With serial antenna. Check XDA forum or google about GPS fix MTK chipset or tell me, I can write a fast manual how to do that...
i managed to make a new GPS antenna. i took a copper adhesive and made a copy of the original one.
now i get a fix but SNR is around 35.
then i closed the back cover and got 30 SNR.
so i put another 2 slice of copper (9cm long) on the cover (one is touching the GPS antenna) and now i got 35 SNR.
but it is not enough. we need around 40-42 snr with 1-2 satellites in order to navigate in the city.
can anyone post a new GPS antenna mod that we can use with a copper adhesive?
You are probably best off finding a microstrip "patch" antenna optimized for
one of the two main GPS frequencies 1.57542 GHz (L1) and 1.2276 GHz (L2).
You could also attempt to build one, like you did, but with optimized
dimensions. These could be very small, on the size of a penny.
THIS is the basics of Microstrip (Patch) Antennas. You should definitely
try that design first! However, I don't know the impedance (the length of W
in the figure below) needed for your device, so you'll have to do some
trial-and-error...
Within THIS rather technical document, there are several simple designs that
you may try to make with your copper-tape-strips.
Finally try Google "homemade DIY gps patch antenna".
Let us know how it goes!
Here are some ideas:
Or perhaps this one?
E:V:A said:
You are probably best off finding a microstrip "patch" antenna optimized for
one of the two main GPS frequencies 1.57542 GHz (L1) and 1.2276 GHz (L2).
You could also attempt to build one, like you did, but with optimized
dimensions. These could be very small, on the size of a penny.
THIS is the basics of Microstrip (Patch) Antennas. You should definitely
try that design first! However, I don't know the impedance (the length of W
in the figure below) needed for your device, so you'll have to do some
trial-and-error...
Within THIS rather technical document, there are several simple designs that
you may try to make with your copper-tape-strips.
Finally try Google "homemade DIY gps patch antenna".
Let us know how it goes!
Here are some ideas:
Or perhaps this one?
Click to expand...
Click to collapse
I added 10/15 points just with this
i hope to be helpful to you
i already tried the microstrip gps antenna. it gives great results but when you close the cover... poor results!
chenrp said:
i already tried the microstrip gps antenna. it gives great results but when you close the cover... poor results!
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Click to collapse
If that is the case, you're probably doing something right!
The cover itself changes the properties of the antenna, usually they compensate this with a velocity factor. What happens, is that the antenna seem larger than it should be, when the cover is closed. Try to compensate by reducing your micro-strip dimensions by multiplying them with ~0.97. Microstrip and patch antennas have a very narrow band-width... (You'll have to be accurate to the mm.) Also make sure the antenna is not touching anything inside, when the cover is closed, as that would again change the properties.
GPS antennas...
E:V:A said:
If that is the case, you're probably doing something right!
The cover itself changes the properties of the antenna, usually they compensate this with a velocity factor. What happens, is that the antenna seem larger than it should be, when the cover is closed. Try to compensate by reducing your micro-strip dimensions by multiplying them with ~0.97. Microstrip and patch antennas have a very narrow band-width... (You'll have to be accurate to the mm.) Also make sure the antenna is not touching anything inside, when the cover is closed, as that would again change the properties.
Click to expand...
Click to collapse
I have three, two are active devices, with the receiver attached beneath, and require +3 VDC supply and RS-232 for data.
One is a ceramic patch from O.E.M Garmin, as supplied in their hand held units,
The third, is a patch used by old Garmin Flight navigator unit I used in my B-55 Baron. Its dimensions are 2-3/8" on a side, soI doubt you could fit this inside without difficulty, let alone altering the dielectric constant of the board.
But if you have a sizable space between the cover and the main board, you may be able to fit a small ceramic patch antenna that should work nicely, IF the feed impedances are similar.
he enclosed pics should give you a starting point though..
i managed to get 43 SNR! inside my house near the window.(with one stripe connected directly to the antenna contacts)
but i cant fit it inside the phone and still get above 35 SNR.
befano71 said:
I added 10/15 points just with this
i hope to be helpful to you
Click to expand...
Click to collapse
chenrp said:
i managed to get 43 SNR! inside my house near the window.(with one stripe connected directly to the antenna contacts)
but i cant fit it inside the phone and still get above 35 SNR.
Click to expand...
Click to collapse
It's pointless to tell us what you get without also telling us what you did or have!
Please post the exact measurements.
E:V:A said:
It's pointless to tell us what you get without also telling us what you did or have!
Please post the exact measurements.
Click to expand...
Click to collapse
"but i cant fit it inside the phone and still get above 35 SNR."!
pointless to write how i did it if i cant put the antenna inside the phone!
I posted a picture.
Try doing as I did.
2mm aluminium tape 7cm long attached inside the cover like showed in the photo.
no need to dissassemble or cut or disconnect.
It seems wierd bit it worked for me and other w8s owners
connection to the antenna:
i disconnected the original antenna. taped an adhesive copper film to the antenna contact(in the board).
the film is very short, just enough to touch the back cover.
antenna:
on the back cover, i added adhesive copper antenna.
that way, we have a long antenna (should be ~9cm long) and is far enough from the phone so get better SNR.
see picture.
GPS foil antenna.
chenrp said:
connection to the antenna:
i disconnected the original antenna. taped an adhesive copper film to the antenna contact(in the board).
the film is very short, just enough to touch the back cover.
antenna:
on the back cover, i added adhesive copper antenna.
that way, we have a long antenna (should be ~9cm long) and is far enough from the phone so get better SNR.
see picture.
Click to expand...
Click to collapse
You can use stained glass copper foil, they make several different varieties, and most have an adhesive backing, as well as natural copper and black oxide, but the black foil does not solder well, so stay with the natural copper for best results.
Did you match the feed impedance to the receiver? You need a proper load to cause the antenna to operate properly, and at 'L' band and higher, this matters even more-so.
Skin effects vary with frequency, and the higher you go, the more effect this has on any RF path, and can kill a receiver's ability to 'hear'.
GPS signals are already weak, and since 99.99% of the nation are not on the high accuracy portion of the 'L band, we are relegated to 1575.42
If anybody would like to attempt this mod, I would be happy to supply the foil, as I use the same material for rebuilding circuits, and have several rolls. Just send appropriate postage and I will send you more than enough to apply this modification to your device.
I guess you can Email me directly, or through XDA.
AECRADIO said:
You can use stained glass copper foil, they make several different varieties, and most have an adhesive backing, as well as natural copper and black oxide, but the black foil does not solder well, so stay with the natural copper for best results.
Did you match the feed impedance to the receiver? You need a proper load to cause the antenna to operate properly, and at 'L' band and higher, this matters even more-so.
Skin effects vary with frequency, and the higher you go, the more effect this has on any RF path, and can kill a receiver's ability to 'hear'.
GPS signals are already weak, and since 99.99% of the nation are not on the high accuracy portion of the 'L band, we are relegated to 1575.42
If anybody would like to attempt this mod, I would be happy to supply the foil, as I use the same material for rebuilding circuits, and have several rolls. Just send appropriate postage and I will send you more than enough to apply this modification to your device.
I guess you can Email me directly, or through XDA.
Click to expand...
Click to collapse
theory and practice aside!
i calculated and learned about GPS L band and the results are not satisfying at all.
the only thing that really helped is the one i posted.
i put the iphone 4 antena and it work verry good
after few atempt to assembly my own antena without success i put the iphone 4 antena .
i get to 38 snr sometimes
this is what i have in a almost stormy day almost sea height with the help of the little alluminium strip.
just have to cut an adhesive aluminium tape, 2x70 mm and stick in in the back cover as shown in the picture.
put the cover back on and u'll see the sat levels growing 10-15% more than before.
maorhadad said:
after few atempt to assembly my own antena without success i put the iphone 4 antena .
i get to 38 snr sometimes
Click to expand...
Click to collapse
have you connected the iphone's antenna to yours? is there any connection there?
chenrp said:
have you connected the iphone's antenna to yours? is there any connection there?
Click to expand...
Click to collapse
Not my brother.
Just peeled the metal band that in the back of the iPhone 4, and stuck it in the back of my bewond W8 as seen in the picture.
before i did it id do that guide :
thlmobilestore.com/news/gps-fix
It helps a little but not enough.
After I stuck the antenna of the iPhone 4 that comes a high precision level and not lose reception when I move for a second under a bridge or something like that ....
Custom GPS tAntenna
Used kitchen aluminium foil, as befano71 suggested ["2mm aluminium tape 7cm long attached inside the cover like showed in the photo"]. Built in a hurry, and might not be with perfect measures, but these are results on a foggy, cloudy evening (I was leaning through a window of a building, hence some satellites are zeroed). GPS fix in <10sec ...
Custom made aluminium foil GPS antenna for THL W8S:
Before mod:
After mod:

[Q] GSM signal booster

Hi
In my apartment in one room there is pretty good gsm signal and in other room the signal is very weak. Is there any quick and not expensive solution to improve the signal?
I found one item on ebay, and just wandering could this small tag solve the signal problems?
http://www.ebay.co.uk/itm/Galaxy-S4...ell_Phone_Signal_Boosters&hash=item20dab0a1ff
Thanks
Being a licenced radio operator I have come across many strange antenna design's over the years and scratched my head trying to understand how the hell it could possibly work, regarding the tag you found, I highly doubt it would do anything, reason,
1. its not physically connected to the antenna circuit of the phone, Inductive coupling does work, but with the losses involved in this design, it would be highly sceptical you would notice any improvement.
2. They want you to place it "under the battery" this in turn would de-tune the resonate frequency of the antenna due to capacictive and inductive coupling of the battery and surrounding phone circuitry. Assuming it even works properly in the first place. And at cellphone radio frequencies a tiny change can cause the antenna to not be resonate.
Having said all that I have witnessed some strange things regarding antennas and with new ideas and designs I guess anything is possible.
For a few $ why not give it a try and report back.
Sent from my GT-I9505 using xda app-developers app

[Q] Any way to boost NFC signal?

I'm using an Element Recon Carbon Fiber case and while I really like it, the carbon fiber seems to weaken nfc. I had a couple tags in my car and room that I can't seem to use anymore. Do things like these external antennas (http://www.amazon.com/ipartstore-Ant.../dp/B00DE76XNY) or similar ones work at all? Its not really a dealbreaker since I still like the case, but I was just looking around if there was a cheap fix available.
pinoysw1mmer said:
carbon fiber seems to weaken nfc.
Click to expand...
Click to collapse
Carbon fiber is a lossy conductor, so it will reduce your NFC range. Thick cases are also problematical. You should consider using a thin plastic or rubber case. Or no case if NFC is important to you. Also orientation is also important, so the position that you hold the phone can help achieve a successful read.
The maximum coupling and therefore range is when the two antennas are parallel. So if you have trouble with a transponder (reader), hold your phone in direct contact with the NFC pad. Level, with the center of the battery door oriented over the pad and hold it stationary for a few seconds if necessary.
I can't think of anything plausible that you could do in software. Phones already use an efficient spiral loop antenna. About the only other thing that you can do is use an external antenna as you alluded to. This could be a solution for you provided that you are willing to not use your battery door and therefore lose your water resistance. If you have a good mechanical aptitude you could possible route the leads through the battery door to an external antenna with a water tight seal. But that would be outside the capabilities of most end users.
The easiest way to increase range is from the POS end, which isn't in your control. Each new generation of transponders are more efficient and tend to increase range. And thieves have been known to hack transponders with much higher, illegal power levels that can capture your NFC information from several meters.
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