[Q] Galaxy note antenna, attention all RF geeks. - Sprint Samsung Galaxy Note II

So the interesting thing I've found about the Galaxy 2 note, is that its antenna is attached to the back of the case, not part of the PCB. That would tell me that it would be really easy to get a replacement back, with, or attach a standard 50 ohm coax connector to the back of the case.
I was thinking it would be fun to make a simple multiband Di-pole antenna, should be about 6" from end to end, I'm not sure if the bandwidth is wide enough, unless one does a folded dipole, not sure how easy it is to do a multi-band folded.
Any antenna DIY'ers out there? I know choosing the right Center is the most important, not sure about antenna bandwidth requirements.
Impedance matching for Folded Dipole necessary?

spodemaster said:
So the interesting thing I've found about the Galaxy 2 note, is that its antenna is attached to the back of the case, not part of the PCB. That would tell me that it would be really easy to get a replacement back, with, or attach a standard 50 ohm coax connector to the back of the case.
I was thinking it would be fun to make a simple multiband Di-pole antenna, should be about 6" from end to end, I'm not sure if the bandwidth is wide enough, unless one does a folded dipole, not sure how easy it is to do a multi-band folded.
Any antenna DIY'ers out there? I know choosing the right Center is the most important, not sure about antenna bandwidth requirements.
Impedance matching for Folded Dipole necessary?
Click to expand...
Click to collapse
Do you mean the antenna that's attached to battery cover? That's the NFC antenna.

chunology said:
Do you mean the antenna that's attached to battery cover? That's the NFC antenna.
Click to expand...
Click to collapse
Yes so what thats for electro pay station type stuff, or phone coupling?

chunology said:
Do you mean the antenna that's attached to battery cover? That's the NFC antenna.
Click to expand...
Click to collapse
If thats the case I was planning on getting the testpoint Coax for the Epic 4G touch, and making a multiband Dipole, but perhaps I haven't investigate far enough to see what coax testpoints the GN2 has. I think one could make a fairly robust, multiband dipole with some brass tubing, or even thick copper wire, and it would be relatively cheap and simple.

yes the back antenna is the nfc, that was done to take it off the battery
Sent from my SPH-L900 using xda app-developers app

also why the f would you need an rf antenna on our phone? sounds like you love the only thing you know too much without understanding how much you could duck up the phone if you mess up
Sent from my SPH-L900 using xda app-developers app

Now you're having real fun. Antennas and radios. Nothing more fun Hardcore Ham radio guy here. You oughtta just make a yagi and get some real power
Sent from my SCH-R950 using XDA

na7q said:
Now you're having real fun. Antennas and radios. Nothing more fun Hardcore Ham radio guy here. You oughtta just make a yagi and get some real power
Sent from my SCH-R950 using XDA
Click to expand...
Click to collapse
Yes I was thinking a yagi would be nice to play with, but I, haven't found much on designing multiband Yagis.
The Multiband Dipole should be really simple, and probably would make a nice small home antenna, where you can find a great spot, and orient it for reception. I imagine some of the tricks they pull in the phone to make the 1/4 wave antenna in the phone, multi band don't help much with gain...
Also one could use an old digital TV satellite dish and get really good gain.
zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

http://www.ifixit.com/Guide/Galaxy+Note+2+-+N7100+Complete+Disassembly+&+Assembly/11811/1
Hmm doesn't look like they are using an antenna rf combiner to feed one antenna like the E4GT.
an antenna for 4g, as well as 3g, be interesting to play with, doesn't look like the 4G has a test point interrupt??

Sigh RF isn't that scary, guys... Sloted line, Wave Guide, SWR meters... Lets make some antennas

Related

Anyone else with a DIY docking station?

Here is a quick one that I put together this morning at work. Luckily I had my old Tilt (not tilt2) here.
http://imgur.com/ICVP3l&vpjvI
phlunkie said:
Here is a quick one that I put together this morning at work. Luckily I had my old Tilt (not tilt2) here.
http://imgur.com/ICVP3l&vpjvI
Click to expand...
Click to collapse
Nice! That's a great idea I am going to have to think something up for this and my Nexus One.
phlunkie said:
Here is a quick one that I put together this morning at work. Luckily I had my old Tilt (not tilt2) here.
http://imgur.com/ICVP3l&vpjvI
Click to expand...
Click to collapse
i just made the EXACT same thing at work with the exact same hp keyboard, thanks!
domin8 said:
i just made the EXACT same thing at work with the exact same hp keyboard, thanks!
Click to expand...
Click to collapse
That's where my keyboard went! Don't worry I have another.
Sent from my SAMSUNG-SGH-I897 using XDA App
I too have been trying to make one, although I'm trying to make one of slightly higher quality. To me the method you have chosen sort of makes it a more attractive option to just have it be laying on the table. I have been experimenting with several prototype concepts of mine and I will consider sharing if any of them work. My biggest limitation obviously is the lack of a 3d printer, so I have to make it out of sculpt-able materials.
Sweet, please keep us updated.
Sent from my SAMSUNG-SGH-I897 using XDA App
I just made one over the weekend. I made it out of wood and scrap aluminum that I had laying around. I don't have pictures right now but I will post them if anyone is interested. It is more of a bedside clock radio adaptation for the phone than a desktop dock.
Some"features" and what I did;
1. Small wood box (9"wide X 5" deep X 5" tall).
2. Phone slides/docks into aluminum plate on front.
2a. USB plug goes to wall charger.
2b. Headphone jack goes to amplifier inside dock
3. Internal amp has control nob under the phone for Volume, Bass and Treble.
4. Each side of the dock box has 3" speaker powered by the internal amp.
The first build is black with brushed aluminum plates. By the dimensions listed above you can see the size is slightly large. That is intended to provide good acoustics for the chosen speakers and amplifier. I have not solid mounted the plugs yet as I do not like my fist dock plate design and will be changing it. After the dock plate is finished I will hard mount the plugs for smooth single action docking.
If anyone is interested in seeing this monstrosity I can post up some pics. I am happy with the design but need to finalize it. I think it;s nice considering it was done with scraps around the house.
I made a simple one out of an expired AAA card...
My AAA card expires in 4 weeks. Now I know what to do with it.
Crap this means I have to get an AAA card now...
Very cool, and it is portable.
Shovelhead84 said:
If anyone is interested in seeing this monstrosity I can post up some pics. I am happy with the design but need to finalize it. I think it;s nice considering it was done with scraps around the house.
Click to expand...
Click to collapse
I am interested. Might be the inspiration I need.
phlunkie said:
Crap this means I have to get an AAA card now...
Very cool, and it is portable.
Click to expand...
Click to collapse
I just used my wifes' credit card. I didn't even have to wait for it to expire, it still worked perfectly.
Battlehymn said:
I just used my wifes' credit card. I didn't even have to wait for it to expire, it still worked perfectly.
Click to expand...
Click to collapse
Nice knowing you.
I'll have to go home and get all my woman's cards and test different ideas. I think I'll run them over a magnet first to ensure to no data leakage from the cards.
phlunkie said:
I am interested. Might be the inspiration I need.
Click to expand...
Click to collapse
Ok, here are some shots. Still need to make a new dock plate and I need to epoxy the plugs in place. After the plugs are locked down I will make a small cover for them. The cables you see in the back are USB, AMP Power, and a small jumper for a connection i did not have room for inside.
The speakers are 3" full range with 2.5" drivers and covered with pc fan grills. From left to right the knobs control Volume(power on/off), Bass, and Treble. The use of 1/2" particle board and large air space allows it to give a nice thumb on the lower freq.
The purpose of this is for bedroom clock radio/alarm clock. It is a bit to large and redundant for most computer desks.
Very Nice!!!! You should sell these.
droidal said:
Very Nice!!!! You should sell these.
Click to expand...
Click to collapse
Some others suggested that, too. Would be cool because it can be universal to several model phones. The parts were from junk in my garage and computer room so I am sure it would be hard to replicate. Could be much smaller with the right parts but not sure what kind of cost it would entail. I figured some others on here could give some ideas for the next version and possibly get some inspiration from this one.
Jesus that thing is HUGE!!
I just want a small dock I can sit on my desk at work
Well here is my dock. Simple and small.
YellowGTO said:
Well here is my dock. Simple and small.
Click to expand...
Click to collapse
What was\is that thing?
Side note: what year gto?
aloant said:
I made a simple one out of an expired AAA card...
Click to expand...
Click to collapse
on a side note what clock/weather widget is that? Looks nice

Idea for alternative charger connector (updated 3/7)

There have been a lot of complaints about the flimsy connector for the Xoom charger. I also think that it is a very poor design at most. The metal pin is too long, the plastic part is poking out too much etc.
I am no engineer and also bad at drawing but I attached something that I think might work. If anyone feels like they could produce a prototype that would be awesome!
The small magnet might or might not work. If you look at the area where all the connectors are you will see a small metal plate that could probably be used to anchor the connector magnetically.
Any feedback is appreciated (even just to say that I am full of sh!t!)
UPDATE: I added an alternative design using the two metal connectors for charging and a silicone plug to keep the connectors in place. A magnet will give additional stability.
funnycreature said:
There have been a lot of complaints about the flimsy connector for the Xoom charger. I also think that it is a very poor design at most. The metal pin is too long, the plastic part is poking out too much etc.
I am no engineer and also bad at drawing but I attached something that I think might work. If anyone feels like they could produce a prototype that would be awesome!
The small magnet might or might not work. If you look at the area where all the connectors are you will see a small metal plate that could probably be used to anchor the connector magnetically.
Any feedback is appreciated (even just to say that I am full of sh!t!)
Click to expand...
Click to collapse
It charges my Xoom very fast. It is still working and has not caused me any issues. If it breaks, I will come back here to *****.
I was just referring to the connector but thanks for the warning
funnycreature said:
I was just referring to the connector but thanks for the warning
Click to expand...
Click to collapse
So was I. The stock one works fine however, alternatives are great as well. I just do not see a need for one personally. Others may.
Yeah, the stock connecter scares me. I like your design though I'm not sure anyone here has the means to develop and sell it. I'm hoping maybe someone may find a softwear solution to charge via the USB micro port. What do you guys think, possible or no?
funnycreature said:
There have been a lot of complaints about the flimsy connector for the Xoom charger. I also think that it is a very poor design at most. The metal pin is too long, the plastic part is poking out too much etc.
I am no engineer and also bad at drawing but I attached something that I think might work. If anyone feels like they could produce a prototype that would be awesome!
The small magnet might or might not work. If you look at the area where all the connectors are you will see a small metal plate that could probably be used to anchor the connector magnetically.
Any feedback is appreciated (even just to say that I am full of sh!t!)
Click to expand...
Click to collapse
I like it! i think its a pretty good idea. Wish i knew someone who could create one. I would buy it. stock one scares me
how the F do magnets work?
anyhow, yeah really good design. I would buy that too.
i just turn it upside down while charging it.
I would buy one of those
I have to ask, why you would use that connector at all if you want to redesign a magnetic charger? Why not use the same priciple to connect it to the two plates on the bottom next to the hole for power?
As someone who repairs laptops for a living, this was the single most troubling design aspect of our new toy. It looks like it will be far to easy to damage the internals of this device with the default power cable.
It would make more sense to use a breakaway magnetic connection that makes contact with the two metal plates. I have not looked in to it too far but it would seem that the docs use this and the USB in them is strictly for audio out.
I was actually wondering if the metal plates would be used for dock charging. Since I don't own a dock I can't check. But if it is then yes, the charger should be attached magnetically! Thanks for the clarification. I'll try to design more options
Sent from my Xoom using Tapatalk
keitht said:
So was I. The stock one works fine however, alternatives are great as well. I just do not see a need for one personally. Others may.
Click to expand...
Click to collapse
My only complaint with the xoom, honestly is the charging system.
For starters, I don't see a reason to not allow charging over USB. Sure the voltage would only be 5v, and it would take considerably longer, but the option would be nice. This isn't to say I want to do away with the 12v charger, because the speed at which it charges is lovely, just the option for the other.
Secondly, the needle-like connector screams, "I want to be broken quickly!" Was there really a need to make the connector in that type and size?
Thirdly, the placement of the charger port is hideous and impractical. It's dead center at the bottom. I rarely use my xoom flat against a surface. I purchased the display portfolio that motorola made. The charger port is not only a hinderance to the utilization of my portfolio case, but is also covered at all times when using the case in any manner that motorola designed it. I'm sure this is simply a brain-fart on motorola's part, which happens to everyone and is understandable, but is there a reason the charger port couldn't have been placed on one of the sides of the device? I would say preferably the left hand side, as people are less likely to turn the device to sit on that side.
I'm not simply posting this to complain, just express my thoughts on the only true fault that I feel the xoom has. On that note, a 90 degree *honestly 180 degree by the design sketch* connector would be lovely, IMO. It still wouldn't be usable with the portfolio case, but it would allow someone to angle the xoom without fear of breaking the charger off inside it.
The two metal plates are indeed for charging on the dock. It takes away the need to use the stock charger on the needle tip. Just plug the charger into the dock and set the Xoom on it. I charge this way every time.
markbo2000 said:
The two metal plates are indeed for charging on the dock. It takes away the need to use the stock charger on the needle tip. Just plug the charger into the dock and set the Xoom on it. I charge this way every time.
Click to expand...
Click to collapse
Only problem is that's a $70-$120 solution
Why even have the plug then and just use the metal plates?
xlGmanlx said:
Why even have the plug then and just use the metal plates?
Click to expand...
Click to collapse
The plug would add additional stability so that it doesn't come off so easily. Not sure how strong you could make the magnets. As I said, I'm no engineer
Makes sense, maybe a smaler nub though haha, otherwise I like the idea
funnycreature said:
The plug would add additional stability so that it doesn't come off so easily. Not sure how strong you could make the magnets. As I said, I'm no engineer
Click to expand...
Click to collapse
Apple has a patent on the magnetically attached charger. Perhaps this is why motorola went the direction that it did.
http://patft1.uspto.gov/netacgi/nph...XT&s1=7311526.PN.&OS=PN/7311526&RS=PN/7311526
im gonna make this. I will let you guys know how it works. my first android by the way!
Sweet! I was also thinking about getting some latex and a second charger that I can strip and modify. This will be so cool!
Sent from my Xoom using Tapatalk

Made a plexi glass dock!

Well, its still in rough shape, need to do some sanding etc... but here it is.
It uses two very small screws to charge through the pogo pin connection.
I wanted it originally to be entirely clear, but I messed up with some super glue and made it turn white, so I may paint it. Also thought about embedding an LED and etching a logo into the back to make it "glow"
Anyway, I'll get better pics with some progress soon hopefully
Sent from my Galaxy Nexus using XDA
Very cool idea! Good way to easily be able to line up the charging contacts at the very least.
This is awesome! I know a lot of people are using different alternatives for the pogo plunger pins and was curious how yours were working? You said you are using small screws? Do you have any trouble with them scratching the actual pogo connections on the phone? That was my only concern for people that were using things like screws, guitar strings, and nails even.
I would like to see a close up of your contact pins. It does seem like each of us has come up with slightly different methods and materials (other sping pins, guitar string, contact prongs, copper tape, screws, tack pins...)
question : How fast does it charge? I'm scared it might be slower compared to the wall plug
Right now charging via the pogo pins is sensed as USB by the stock ROM and limited to 500 miliamps.
There is a kernel that can be flashed to force full AC charging mode.
We believe this is the issue holding up the aftermarket pogo accesories, as manufacturers dont want their product reputation hurt by charging not keeping up with power use on devices that are actually limited by the software.
Everyone is hoping that the next OTA update will have the fix....
subvertz said:
Right now charging via the pogo pins is sensed as USB by the stock ROM and limited to 500 miliamps.
There is a kernel that can be flashed to force full AC charging mode.
We believe this is the issue holding up the aftermarket pogo accesories, as manufacturers dont want their product reputation hurt by charging not keeping up with power use on devices that are actually limited by the software.
Everyone is hoping that the next OTA update will have the fix....
Click to expand...
Click to collapse
Well that sucks. I remember in the sensation or nexus forum there was a fix for this... something about soldering an extra thingie.
Sent from my Galaxy Nexus using xda premium
I'll try and get a pic of the screws later tonight after work. I do have a scratch that I suspect is from them, however I'm sure something can easily be changed so that doesn't happen. Unfortunately I dropped my phone last week and chipped the screen, so I'm not worried about a scratch at this point.
If the sharpness of the screws is/was a problem I had planned to just grind them down and make them smooth and rounded, which I'm sure is still a very viable option.
As for the comment on speed, I guess that's already been pretty well answered. I was only going to add that I haven't paid attention, I've just been using this to charge my phone while I sleep.
I also plan to add an nfc tag or something to put the phone into the dock mode and set alarms or whatever.
Sent from my Galaxy Nexus using XDA
These were a few prototypes I'd made a little while back. No charging pins at this point. If you need any help with the plexi, let me know.
Mine are basically just phone holders at this point
Sent from my Galaxy Nexus using Tapatalk
plasticdarlow said:
These were a few prototypes I'd made a little while back. No charging pins at this point. If you need any help with the plexi, let me know.
Mine are basically just phone holders at this point
Sent from my Galaxy Nexus using Tapatalk
Click to expand...
Click to collapse
Ummm...daddy like. Are you going to be selling those? If so, how much? I dont need it to have a charger. I just need something to hold up my device on my desk. While the gogostand I use is good, its just not android enough for me.
I would buy a dock with charging pins if you made one.
plasticdarlow said:
These were a few prototypes I'd made a little while back. No charging pins at this point. If you need any help with the plexi, let me know.
Mine are basically just phone holders at this point
Sent from my Galaxy Nexus using Tapatalk
Click to expand...
Click to collapse
Very nice, what are you using to cut with? I just kinda went at it blind, not much of a real "plan". If I make another it will be a lot better looking, but seriously doubt I could pull off anything even close to yours
Sent from my Droid using XDA
bill12690 said:
Very nice, what are you using to cut with? I just kinda went at it blind, not much of a real "plan". If I make another it will be a lot better looking, but seriously doubt I could pull off anything even close to yours
Sent from my Droid using XDA
Click to expand...
Click to collapse
my guess is a jigsaw > rough sand paper to smooth > wet and dry sand paper > blow torch
bill12690 said:
Very nice, what are you using to cut with? I just kinda went at it blind, not much of a real "plan". If I make another it will be a lot better looking, but seriously doubt I could pull off anything even close to yours
Sent from my Droid using XDA
Click to expand...
Click to collapse
No really a fair comparison since I work for a plastic manufacturing company . I used a 400 watt laser to cut those parts out. I also have 3 & 5 axis CNC machines. I'm toying with the idea of casting a molded base but need to 3d scan my phone for the proper geometry.
Figured it was lasered or something similar. I only wish I had access to some equipment like that. Cordless dremel just doesn't quite do the job
Sent from my Droid using XDA
RedBlueGreen said:
my guess is a jigsaw > rough sand paper to smooth > wet and dry sand paper > blow torch
Click to expand...
Click to collapse
I wish. But your right, you could sand and flame the edge to acheive that look.
bill12690 said:
Figured it was lasered or something similar. I only wish I had access to some equipment like that. Cordless dremel just doesn't quite do the job
Sent from my Droid using XDA
Click to expand...
Click to collapse
Yeah, it's pretty nice having the machinery to make pretty much anything I want.
plasticdarlow said:
Yeah, it's pretty nice having the machinery to make pretty much anything I want.
Click to expand...
Click to collapse
Hook me up with one! I'd love to have something for my phone like that especially if you get the pins put into there. But if not then at the very least it can do double duty for my tab as well.
Pretty slick looking ideas. I've always thought of making a couple of those for my office, home, and bedside.
I also heard that they have a new kernel that forces Fast Charging regardless of the connection. I know right now I'm running Axi0m Hybrid and it has a status bar toggle for Fast Charge. I haven't tested it out though.
I'd buy one
Sent from my Galaxy Nexus using Tapatalk
manningfan10 said:
I'd buy one
Sent from my Galaxy Nexus using Tapatalk
Click to expand...
Click to collapse
I'd buy four.

Need help identifing antenna in G2

So I was thinking about boosting my antenna signal with those Antenna Booster stickers. I know a lot of people say they don't work, but I think it's because they're not positioned correctly.
Anyway here's a picture of an unfortunate G2 I bought off Ebay used to repair my working G2. I keep it around for spare parts. Are those copper contacts really the antenna? Looks like the metal materials runs under a portion of plastic to extend the range.
I believe that the bottom is for cell use while the top is for blue-tooth and wifi. I was thinking of buying a couple and doing this too boost the phones signal.
There's enough empty space to place these stickers in there and try to boost the signal. Compared to some other phones I've had, this one has a rather weak signal in comparison. Especially in those spotty areas.
Not to rain on your parade but if a $4 sticker that probably costs .04 to make really helped at all, don't you think phone manufactures would already be using them? Any way you identified the antenna correctly, have at it
Sent from my HTC Vision using xda premium
Thanks, I ordered a pack of 6 for $3. I'll report if there's any noticeable difference. I've used one long time ago on my Motorola Razer and seemed to work.
Really wish this phone came with a better loud speaker.
It could have been the placebo effect?
About the speaker, do you think we could find one that fits on eBay or RadioShack or whatever? So as to make it louder?
I noticed when I hold my phone with my left hand, the signal really sucks. I knew the cell antenna was in the bottom section and now I know why covering the left side is bad. I try to just hold the top part but it's hard when browsing or other functions besides calls. We all made jokes about the iphone and the "you're holding it wrong" crap but it seems to be true with our G2 As far as booster stickers go, they have been selling these things for many years now. They have never been proven to work and disproven many times. The placement of the boosters don't matter and were allegedly designed to be placed right side up and behind a battery. They don't supply power therefore couldn't act as a repeater or booster nor do they alter the design of the original antenna not to mention they don't even make contact with it. They used to sell for $20 but now sell for 1 penny lol! The only things that ACTUALLY work are external antennas (few phones even have ports for them anymore), cellfi, uma, repeaters, microcells, etc. So, shell out some real cash for a proven booster/repeater or hold your phone differently. Sorry... good idea though! Worth a shot...
Dukenukemx said:
Thanks, I ordered a pack of 6 for $3. I'll report if there's any noticeable difference. I've used one long time ago on my Motorola Razer and seemed to work.
Really wish this phone came with a better loud speaker.
Click to expand...
Click to collapse
Hello,
any news abut possible signal improvement?
I would like to replace the bottom GSM antenna with better one.
I've already tried couple of modifications, but without success.
I would appreciate if somebody could share hardware modification which really works and improves the GSM signal reception.
Thanks
Hi I have a Spanish G2, Desire Z Vodafone and also appears that since the Demonte to change the screen, gives me probemas coverage, always, sometimes puts all stripes and many others did not put stripes or coverage but you can call ...
I've seen the pictures and these metal parts I have them, I do not know to do. : (
I wrote this at forum:
http://forum.xda-developers.com/showthread.php?t=2090365
http://forum.xda-developers.com/showthread.php?p=38019953
Merci

Here's an accessory to extend/add NFC antenna points to Android devices

I thought I'd add some actual NFC hardware 'hacking' to this forum.
http://www.nfcbrief.com/2013/01/flomios-nfc-accessories-extend-antenna.html
These accessories don't make the wireless field bigger, but they allow you to add up to 3 wired NFC antenna contact points, up to 90cm away from the device. I'd imagine some people here might be able to make their own extenders.
What would be awesome is if they used some sort way to extend the range by having am external coil resonate at the same frequency as the internal coil so you don't have to open your device.....just a thought
Sent from my Nexus 7 using xda app-developers app
Awesome.
Sent from my Nexus 7 using XDA Premium HD app
Pretty cool - hand't heard of that before.
extend/add NFC antenna points to Android devices
Wow. Awesome man! :good:
That NFC "band-aid" solution doesn't see to be a bad idea, has anyone tried it out yet and saw how it works?
Sent from my Nexus 7 using XDA Premium HD app
Impedance matching
I bet you could get even further by impedance matching the wiring. Try using some balanced feed line or twisted pair with a shield. The trick will be measuring the correct impedance.
its cool I like also that
Yes, NFC extenders/extensions are easy to build, I've built dozens for our marketing company. All you need to do is have a close approximation of the size and shape of the antenna and a matching length of wire on the other end. I use 32 gauge magnet wire and 3D printed forms, it allows me to move the 'hot spot' from the back to the side or top of the tablet. I use Gorilla tape to adhere the coil in position on the back, no modifications to the tablet are required.
I want to make an extender to move the distance by about six inches. Any tips would be greatly appreciated...

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