Anyone notice that the back cover of the Nexus S has two little gold contacts and some sort of grounding/antenna plane just like the Captivate?
http://cdn.slashgear.com/wp-content/uploads/2010/12/NEXUS-S-Hands-on-09-SlashGear-580x359.jpg
And
http://pocketnow.com/html/portal/news/0000011184/backopen.jpg
Perhaps it's only a ground plane or something, but there is a striking resemblance. We already know our Captivates have a little something special (in the back cover mechanism and inclusion of an Audience voice processing chip) that none of the other Galaxy S variants carry. Just speculation, but maybe there's a NFC radio hiding somewhere in our devices and that "ground plane" is actually the antenna. Perhaps if someone can discover what exactly the NFC antenna looks like (if it's internal, or integrated into the back cover of the Nexus S) we could make a better guess.
Unless someone else has a more reasonable explanation?
well thats an interseting theory. kind of a stretch though, any number of things it can be. i mean because the nexus has two contact points and has nfc doesnt mean that the points are related to nfc. i think that the cappy not having nfc is evidence that the backplate is not used for nfc. but we may have un used hardware, if i knew more about antennas and nfc and things i guess i could draw a better conclusion.
i can tell you that the round point on the cappy goes to ground through a plating on the back of the plastic over. i made no attempt to trace the contact that is on the board. if someone with knowledge in the area of antennas could coment that would be great but it's probably nothing.
I've noticed this too.
If you tilt the back door at the right angle to the light, you can see a vague pattern (at least on mine) which looks like an RFID antenna in the recessed square on the back. Maybe it's something? RF is not my specialty, but it looks awfully like the pic on the left http://www.new-rfid-concept.com/rfid_and_nfc.html.
Merlin_reloaded said:
I've noticed this too.
If you tilt the back door at the right angle to the light, you can see a vague pattern (at least on mine) which looks like an RFID antenna in the recessed square on the back. Maybe it's something? RF is not my specialty, but it looks awfully like the pic on the left http://www.new-rfid-concept.com/rfid_and_nfc.html.
Click to expand...
Click to collapse
Noticed the pattern too. S'why I'm curious what it's for.
Huh, but why would they put an rfid chip in a phone when android is supposed to start using nfc? My guess as to the contact points are wifi antenna contacts. I noticed I get amazing wifi pickup from routers far away. Much better than any other device I've used. Although, no signals loose reception quality when the back plate is off, wifi, cell, gps. Idk. Haven't tried bt though.
From a phone
boborone said:
Huh, but why would they put an rfid chip in a phone when android is supposed to start using nfc? My guess as to the contact points are wifi antenna contacts. I noticed I get amazing wifi pickup from routers far away. Much better than any other device I've used. Although, no signals loose reception quality when the back plate is off, wifi, cell, gps. Idk. Haven't tried bt though.
From a phone
Click to expand...
Click to collapse
Doubt it's an actual RFID in the back cover. It's just that little patch on the back cover looks very much looks like an antenna.
Really, I don't think it can be something. A mp3 player I owned for 4 years have something like this too. It's most likely to be something like digital ground just to keep the voltage stable...
Shammyh is correct, it is for NFC.
loebotomy said:
Shammyh is correct, it is for NFC.
Click to expand...
Click to collapse
What are you saying? The captivate secretly has NFC? Seems a bit far fetched since found this yet. Would be cool though.
Sent from my GT-I9000 using XDA Premium App
i know this thread is old, but i was searching for the same thing today. after i read this thread here, i found this, explaining some roms that support the chip:
"... Audience Chip support (Captivates have a special chip added that increases call quality... if it is used)." loraqu
@ http://forums.androidcentral.com/t-captivate/111137-cyanogenmod-7-vs-serendipity-vii.html
so i guess its like those weird sticker things they used to sell on tv that claimed "its like adding a 5 foot antenna to your phone!" and im assuming everyone knows by now it cant be nfc because the backplate is metal. i found it interesting, so there it is if anyones still searching.
The signal on this phone is way worse than my old Motorola Milestone. The only time I see green for cell signal in "battery use" is when I'm outside, whereas on the Droid it was almost always solid green. I'm never out of signal but I understand that the better the signal, the less battery use by the radio.
I found a thread in the Incredible S section and a video on youtube that tried to make the antenna in the cover better by sticking aluminum foil onto the back, extending from the pins on the cover.
To test, I first tried taking off the cover (lost signal) and putting 2 thin strips of aluminum directly on the contact pins on the phone to see if I could get signal without the cover. It worked.
I then built 2 random network of strips extending the pins on the cover (without touching the other pin's extension network) and sticking them down with tape. I made contact between the aluminum foil and the pins, and with itself always non-shiney to non-shiney side. I think the shiny side might be coated with something that isn't conductive.
Now the cover is back on but I'm not sure it's making any difference. Still -87db to -97db while holding the phone in the house.
Has anyone else tried this? I might try thin copper wire next.
Any wisdom on how the stock back cover works as an antenna? Isn't it plastic? Is it just the small gold pins?
Let's build a better antenna
Sent from my Sensation using XDA App
I'm not very good but I agree with you the signal are very week
In my house I get 1 bar of signal whereas if just step one foot out of my house the signal bar goes full
Sent from my HTC Sensation using xda premium
You can make one new antenna, but you must remove old one, or else, your new one can not work as you expected. I think original one should not worse than some standard, so flash a new radio package should have some improve one this problem. I have GPS signal weak problem some months ago, but after I flash latest radio package, GPS can be locked within several minutes without a valid data connection. Before that time, my GPS can not be locked within ten minutes.
Take a look over at the HTC Titan forums, there were a few guys over there looking into signal problems and they had all sorts of ideas while I had a Titan. The titan is pretty much a sensation xl with wp7 and the titan, xl and our sensations antennae all work in the same way with the contacts on the phone and battery cover. Hope this helps.
Sent from my HTC Sensation XE using xda premium
sparx180 said:
Take a look over at the HTC Titan forums, there were a few guys over there looking into signal problems and they had all sorts of ideas while I had a Titan. The titan is pretty much a sensation xl with wp7 and the titan, xl and our sensations antennae all work in the same way with the contacts on the phone and battery cover. Hope this helps.
Sent from my HTC Sensation XE using xda premium
Click to expand...
Click to collapse
Thanks, I'll try a search there. Do you remember anything working?
I'm interested to know how the stock antenna/battery cover works first. That'll help me understand how we could improve it.
Sent from my Sensation using XDA
Flyview said:
Thanks, I'll try a search there. Do you remember anything working?
I'm interested to know how the stock antenna/battery cover works first. That'll help me understand how we could improve it.
Sent from my Sensation using XDA
Click to expand...
Click to collapse
They were using copper strips on the outside of the case that worked but obviously was ugly. But last time I checked they were looking into scraping away the top layer of oxidized contacts to get a better contact with the phone. But Titan mobile signal and WiFi signal is waay worse than sensation. Mine was so bad I sold mine and got my XE so I'm sure someone over there could fill you in or you could find something worth experimenting with.
Sent from my HTC Sensation XE using xda premium
hello,
i've tried such things when i had a sensation. I gave up since the problem wasn't that bad for me and for some more effective measures to be taken the phone itself had to be modified in a way that warranty service people would not like.
Anyway, the antennas on sensation are, as you know, located in it's back cover. Those small exposed copper pins make contact to the corresponding locations on the phone. If one would crack open the sensation's back cover and rip off it's 3 layer construction, one would see that those copper pads are linked with some small copper conductor, forming the antenna system. Unlike older htc phones i've hacked, sensation uses a different antenna layout. If I were to try to improve it, i would go by the following steps/rules:
1. Any antenna on these type of devices, is actually a bridge between 2 points, as opposed to more traditional antenna design that has a ground pin (cold connection) and the so called hot wire - the antenna itself. These 2 are separated in normal designs, but since the nature of the wavelengths involved in gsm communications these 2 wires are actually bridged and form something called a ground loop.
2. here's a typical setup for a phone implying the same antenna system like sensation. (click for a larger version)
The small pads (blocks) are pairs used for each wireless functions. So let's say that green is gsm, blue is bluetooth/wlan and red is gps. In the right side, the phone side (without the cover) you can see that these section have their ground connections linked together. If you were to use a multimeter on the phone side and try to measure each point for continuity (with the ground connection - ex. metallic shield of the microusb connector) you will find the ones corresponding to ground.
If you look into the left side, the battery cover part, you will see that each pair has it's pins linked together. At first, if you connect the cover to the phone, it would appear that you actually short circuit everything there and it looks like a huge mess. That's true, but the manner in witch the short circuit is made, creates a ground loop. These are sensible to RF signals and although hated in other areas (hum noise on some audio equipments, etc) they are essential here as they are actually what the phone uses as an antenna.
3. note that since i currently don't have a sensation, the simple graphic representation placed above may not be 100% accurate to what you will find in this particular phone. The ideea remains the same. One must use a multimeter, placed on continuity tester to measure the points on the battery cover then - the ones on the phone. You try to place your probes on those pins - the multimeter beeps, then you've found a pair. On the phone itself you'll find more pins that "beep" when measured together, once you found all of them, you'll figure out what's the phone's ground pins for these antennas.
4. Once you have a pretty good ideea on what is linked to what and how the connections are made, it's time to figure out what antenna does what function. With the back cover removed, you should try to connect each pins corresponding to a pair, you can use a small copper wire (careful not to touch anything else). If you see gsm/bluetooth/wlan/gps working, you would have found what what each pair of pins does.
5. redesigning the whole antenna system would involve placing some copper foil as material for the bridge between the pins. Small copper wire isn't good here, you need something with a greater conductive surface.
6. Experiment, you may notice some improvements but take care how you mix the parts of your custom antenna to the original battery cover. In reality, the results will be less spectacular since the whole design is, if i am to say,well ... badly engineered. The fact that these antennas are almost all the time covered by your hand when holding the phone, doesn't help either. It just proves that simpler designs (like the hd2 for example) are superior in both sensitivity and stability in this matter.
One important note, however. It is recommended that you use surgical gloves and/or use a wrist strap to reduce the amount of static electricity produces by your body and induced on those small antennas. Some of them are very sensible to these things, you may actually further reduce their performance by damaging (reducing overall gain though transistor degradation) the small and delicate input stage of their RF transceivers.
facdemol said:
hello,
i've tried such things when i had a sensation. I gave up since the problem wasn't that bad for me and for some more effective measures to be taken the phone itself had to be modified in a way that warranty service people would not like.
Anyway, the antennas on sensation are, as you know, located in it's back cover. Those small exposed copper pins make contact to the corresponding locations on the phone. If one would crack open the sensation's back cover and rip off it's 3 layer construction, one would see that those copper pads are linked with some small copper conductor, forming the antenna system. Unlike older htc phones i've hacked, sensation uses a different antenna layout. If I were to try to improve it, i would go by the following steps/rules:
1. Any antenna on these type of devices, is actually a bridge between 2 points, as opposed to more traditional antenna design that has a ground pin (cold connection) and the so called hot wire - the antenna itself. These 2 are separated in normal designs, but since the nature of the wavelengths involved in gsm communications these 2 wires are actually bridged and form something called a ground loop.
2. here's a typical setup for a phone implying the same antenna system like sensation. (click for a larger version)
The small pads (blocks) are pairs used for each wireless functions. So let's say that green is gsm, blue is bluetooth/wlan and red is gps. In the right side, the phone side (without the cover) you can see that these section have their ground connections linked together. If you were to use a multimeter on the phone side and try to measure each point for continuity (with the ground connection - ex. metallic shield of the microusb connector) you will find the ones corresponding to ground.
If you look into the left side, the battery cover part, you will see that each pair has it's pins linked together. At first, if you connect the cover to the phone, it would appear that you actually short circuit everything there and it looks like a huge mess. That's true, but the manner in witch the short circuit is made, creates a ground loop. These are sensible to RF signals and although hated in other areas (hum noise on some audio equipments, etc) they are essential here as they are actually what the phone uses as an antenna.
3. note that since i currently don't have a sensation, the simple graphic representation placed above may not be 100% accurate to what you will find in this particular phone. The ideea remains the same. One must use a multimeter, placed on continuity tester to measure the points on the battery cover then - the ones on the phone. You try to place your probes on those pins - the multimeter beeps, then you've found a pair. On the phone itself you'll find more pins that "beep" when measured together, once you found all of them, you'll figure out what's the phone's ground pins for these antennas.
4. Once you have a pretty good ideea on what is linked to what and how the connections are made, it's time to figure out what antenna does what function. With the back cover removed, you should try to connect each pins corresponding to a pair, you can use a small copper wire (careful not to touch anything else). If you see gsm/bluetooth/wlan/gps working, you would have found what what each pair of pins does.
5. redesigning the whole antenna system would involve placing some copper foil as material for the bridge between the pins. Small copper wire isn't good here, you need something with a greater conductive surface.
6. Experiment, you may notice some improvements but take care how you mix the parts of your custom antenna to the original battery cover. In reality, the results will be less spectacular since the whole design is, if i am to say,well ... badly engineered. The fact that these antennas are almost all the time covered by your hand when holding the phone, doesn't help either. It just proves that simpler designs (like the hd2 for example) are superior in both sensitivity and stability in this matter.
One important note, however. It is recommended that you use surgical gloves and/or use a wrist strap to reduce the amount of static electricity produces by your body and induced on those small antennas. Some of them are very sensible to these things, you may actually further reduce their performance by damaging (reducing overall gain though transistor degradation) the small and delicate input stage of their RF transceivers.
Click to expand...
Click to collapse
Awesome!!! Thanks bud. I'm gonna bust out the multimeter.
So the antenna is basically some copper inside the cover connecting two adjacent pins? I assume just connecting them straight isn't the best antenna (or else they would have just done that on the phone). [EDIT: Ah, for the other two antennas, they are indeed linked with a straight piece of copper. The GSM antenna is two small contacts that I assume are somehow linked through the inside of the cover] Is this connection actually long (distance) within the cover?
Also, what are those "extensive modifications" that would actually create a big difference? I bought my phone second hand so I don't think I have warranty (or do I?). Is it building a traditional ground + hot wire antenna?
Ok, here is what I found. I'm pretty sure I used the multimeter correctly. Didn't have a continuity setting per se, but there was one in the resistance category that had an arrow pointing to a plus and it worked like in example 1 here.
What I found on the cover, is pretty much what we expected.
What I found on the phone is kind of surprising: each pair is connected to itself. Each pin is connected to the ground already as well, EXCEPT for 1 near the top.
Thoughts on how the ground loop is generated and what to try bridging with copper foil next?
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the design i've draw in the previous post, took the simplest design when using a ground loop in a phone like the sensation. As you can see, in reality, things are a bit more complex. Since you have those pins already connected one to another and those pairs to the phone ground (usb metallic shield) you already have a ground loop inside the phone and you actually extend it when you place the back cover.
Without trying to be more technical about multilayer pcb design or ground planes on a pcb, let's see what can be done about the gsm antenna and it's performance.
1. a logical first step would be to identify the pins corresponding to this antenna. Try to make some sort of cable with one end that can be fitted over those pins on the phone and the other end to an external antenna (piece of metal, if needed, use a simple metallic spoon or fork). The cable has to have 2 smaller cables inside, one for each pin. Once you find where are the pins for the gsm antenna we can proceed further. You may want to try other means to identify this, it's just that you may need a cable later on this "guide" so i've suggested to have one ready.
2. it's kind of difficult to experiment with high frequency antenna designs since there are no hobby tools capable of measuring these kind of frequencies (in the 0.8 - 1.8 - 2.4 Ghz area) and neither their amptitude in a given circuit. Since the phone itself has some means to measure this, we'll .. aah, use the phone. Signal bars, dB meters, whatever you find relevant. Another thing i do when i experiment, is to .. oversize things for more visible and clearer results. Of course, if, let's say you have a broken old phone and want to see if it still works, you won't remove it's battery and plug it to a car battery - you will blow it up. That's not one of those things were you want to oversize. Helpfully, antennas are of different nature. So, when you have to decide if a particular type of antenna is helpful, make a bigger one just like it. If the bigger one works, and the smaller one doesn't - then the design works but it's a size problem. If the bigger one doesn't work, then surely the smaller one won't work either here so you shouldn't try to make one to fit in the phone.
3. So, you got your pins right and know what's the gsm ones. Let's talk about some of the most simplest designs. Since RF energy is invisible and.. without any tools, impossible to measure, i'll be making an analogy with magnets and magnetic forces because they are of a similar origin but you can observe the effect of magnetic forces applied to an object even if you don't see the actual magnetic fields.
So, here are the 2 examples we’ll be talking today.
As you can see in the picture, the first one is a simple metallic plate and the second one contains 2 plates, one smaller then the other (about ¼) separated and not touching each other. Below each design, you have a representation of what would you see if we were to look at them from their profile, with the antennas standing vertically. Let’s talk about how they work. In case of RF energy, you would have a RF field, a spatial area on witch these waves propagate. If you place a metallic object in this field, an amount of this field’s energy will be passed to the metallic object (the process is called “induction”). We can measure this since this process generates a bunch of free moving electrons inside our metallic object. The stronger the field or the larger the surface area -> we “aquire” more electrons. If the field is too strong, a lot of electrons are being induced, they kind of “rub” on each other and surrounding molecules (it’s called brownian effect) so we produce heat - a microwave oven works like this. If we still were to pump up a greater field and to induce more energy, we will produce more heat. If we still try to induce more energy, we will obtain nuclear fusion. If we find ourselves rather more insistent and still try, we will obtain energy-matter convesions (like einstein's e=mc2) and if we still try to induce more and more energy, the matter we create will collapse under it's own gravitational field, thus we'll obtain a small black hole and surely we'll get banned from XDA for this. But to scale things down a bit and still talk about some lonely electrons, based on the general definition of the electric current, our electrons constitute a small electric current induced in the metallic object by that RF field. In a phone, that electric current is what’s being filtered and amplified. All forms of RF fields work just like this, so in the phone’s case, gsm, wlan, bluetooth etc. Thus, we need to “aquire” (it’s not the most physically correct term.. I know, but I try to keep it simple) more electrons. That’s the role of any antenna. The first design works great in areas were you have a relatively good field strength (phone signal) since it offers a big contact surface with the electromagnetic waves. This however is not always enough in places where you have a weaker field since the longer the distance to the source, the more the waves dissipate over a greater surface and from the point of view of a single receiving device – loose energy. The second design is a hybrid between those satellite dishes you may see on top of some buildings and some high gain antenna designs use in wi-fi networking. Simply adding a second metallic plate to the larger one, changes things quite a bit. I’ll get back on it after another schematic, showing how these 2 designs receive those badly needed electrons.
So, you can see, the red square (we’ll call it emitter) and our antennas. In the first case, the red thing emits and the black thing (antenna, profile view) receives those red curved lines (field energy). Because of this, a bit of red “appears” inside the black thing.
The second case looks a bit more complicated and yep.. it is. Remember that some time ago, I’ve talked about comparing RF fields with magnetic fields for the sake of simplicity. Well.. it’s time to do that stuff.. Imagine the red thing as a strong magnet. You have 2 iron plates at some distance from the magnet. You also glue these to keep them secure and not attracted by the magnet. In this setup, we say that we’ve “placed the metallic things inside the magnetic field generated by the magnet” (or something like this). The metallic plates are subjected to the force of the magnetic field, we can observe this easily because we have to keep them secured in place, not to move near the magnet. It’s the equivalent of the RF field described above. BUT something extra is also happening. While being attracted to the magnet the plates also become temporarely magnetized. So, they, themselves, will attract other metallic objects. This means that they have created a magnetic field of their own. The smaller plate, closer to the magnet, produces a larger secondary field, it’s effects reaches the second larger plate and get’s added up to the magnet’s field. Thus, the larger plate, receives a greater magnetic field in this case as opposed to the first example were only one plate is being used. The larger plate will also produce a magnetic field of it’s own, it will also reach the smaller plate, it will be induced in it, then the smaller plate will “re-emit” it to the larger one … and it’s kind of complicated even here.
The fact is, and it’s important, if we get back to waves.. it can go the other way around. Some bunch of electrons moving inside a metal plate will also create a RF field. So, maybe it’s easier to understand now, it’s actually rather difficult to design antennas since they act in both ways. They receive a part of the RF field, but they also can emit at the same time, a part of the energy they just received. The second design incorporates this facts.
4. After all of this.. how do we link those phone pins to these plates? Well that’s simple. In the first case, we will solder of at least secure 2 wires to 2 opposing corners of that plate. Those will be linked to the phone’s pins (polarity doesn’t count here). In the second case, some experiments must be done. First connect the larger plate to the phone, just like in the first case. Observe if you have any improvements, try to also connect the smaller plate to one corner or the other (by another wire). See what produces best results.
5. How big is .. big? When experimenting with larger antennas, I suggest that the larger plate to be around 50cm – 80cm in diagonal.
6. Materials… My choice would be copper. Thickness is very less relevant. Since copper foil is harder to get, you may also use aluminum foil if you manage to secure wires on it. Copper can be found on electronics store as prefabricated “blank” PCB’s. They are pretty cheap also. You can easily solder a wire on them. If you get these things, go for a single plated one, not the ones that have both sides covered with copper.
7. If you find a design that works for you in the large scale, then will try to find a way to make it smaller and fit it the phone's back case. But if the larger one doesn't work, if any large antenna design doesn't improve things much, the smaller ones surely won't help either and the problem must be searched in other places (phone's firmware, hardware etc).
I'm sorry I've got nothing useful to input in this but a guy on here before was suggesting to create a fractal antenna? something that maximizes the area of the back cover. I googled it a bit and though it was a good idea but I totally have no ideas about how to do such.
You can get stickers that you stick inside your back cover that are supposed to improve the signal. I've read mixed reviews as to whether this actually works...
http://www.phoneaccessoriesuk.co.uk/htc-sensation/268-htc-sensation-signal-booster.html
fractal antennas are better in the respect that they minimize the space requirements for antenna modules inside the phone. However, that's not diy stuff
One could try to reproduce the design with various house hold items but at this scale, when talking efficiency a simple copper plate would outperform any household fractal antenna system.
In general, although there are phones with fractal antennas, they are more efficient in higher wavelengths (lower frequencies). For example,you may have seen frigate class military vessels at sea. They have some tall 6-7 meters antennas (not the radar dishes, or "tv antenna like" yagi ones) that look like a simple rod or an extended version of your car's fm radio. They use fractal designs, and what you see as the "antenna tube" is only the flexible, weather proof casing of the actual fractal antenna inside. But they operate on a different band/wavelength.
@chrisw99 those things are actually what i was talking when suggesting my second example for antenna design. The phone's antenna acts like the bigger plate in that example and these stickers do the job of the smaller plate. Actually in theory they should work but because of the fact each phone has a slightly different antenna or placement for the RF module and these stickers try to be the "one size fits all" type, in reality your mileage may vary.
While I like the idea of building a better antenna (I’m going fiddle w/ this tonight after work), this phone has had much better signal, GPS and Wi-Fi then my Nexus 1 could ever dream of having. GPS is instantaneous on|off (N1 would stay on for up to a min after app close), Wi-Fi connects immediately (N1 would show connection but lag before my icon turned green). I have been VERY happy w/ all aspects if it’s signal.
Ahhh, great info to wake up to haha.
The GSM pins, I forgot to mention, are definitely the bottom ones.
I agree, the wifi has great reception (except when touched; very top pins). Is the wifi antenna still propogating through the cover? Or is it just the little strip of contact?
Sent from my Sensation using XDA
normally wifi antenna should be linked to a small copper foil inside 2 layers of the battery cover. That cover seems to be made out of about 2-3-4 layers of plastic, glued together in some way. One thing i never understood, why the holes in the housing?.
If i remember well, when i had the sensation i was most impressed with the gps performance. That was above any other phone i used before. Wifi performance was not that good, especially when browsing in landscape and covering the antenna with one hand. I also had one hd2 and gsm performance was kind of worse in low carrier coverage areas. Things like hd2 having 1-2 lines of signal indicator, sensation - none.
The wireless performance of the sensation is kind of mixed, some people compaining some never having any problems.
What do you think about rewiring the antennas to switch the wifi and GSM? I.e., cover up the contacts and run wires to the other antenna from the now covered original contact points.
P.s. keeping the phone in 2G mode gives me substantially better signal (ex. -69db instead of -83db).
The only reason I want to improve the signal is for battery use for the radio. I haven't actually had no signal anywhere I've gone...yet. Am I correct in thinking more power is given to the radio under "low" signal conditions though?
Sent from my Sensation using XDA
yes, that is correct. Under poor signal, the phone's tranceiver will require more power to operate. The amplifier stage inside the transceiver will need to increase it's overall gain in order to compensate, that uses more power. However, in modern phones we're talking about 1-2mA (max. 3mA) variations in stand by. That's rather small, if we also take notice of the fact that even so, the phone won't draw 2-3mA extra all the time, only when updating it's status with the corresponding GSM cell in your area (that's why they call it "cellular network"). On older phones (i mean really old) yes, that used to be a problem since individual GSM antennas were further apart from each other, phones back then needed to have stronger transceivers inside, that were able to cope with the increased distance. A small fact: the miniaturization of phones today was possible not primarily because of evolution of electronic stuffs that go inside a phone, but because carriers upgraded their networks and newer phones didn't need powerful RF transceivers inside - along with with all their required circuitry. The second most important thing is the development of high performance li-ion / polymer cells and only at third place, the evolutions in cpu/mcu or other highly intergrated circuits that now equip even the most basic phones. Since the bulky old transceivers were gone, we had a lot of space inside to put new things like cameras or bluetooth/wlan transceivers.
About switching gsm with wlan, first of all you must test how big is the improvement. Don't switch it yet, instead place a larger copper aluminum plate for the gsm antenna and check out if it improves things. If you find out that a 0.5 meter plate improves signal reception by only 20%.. well i don't think it will be relevant at the small scale, when you switch the antennas.
Really? Only 2-3mA draw difference between perfect and low signal? I might be mistaken but I remember my old phone's battery draining quicker under low signal.
I'm going to try aluminum first, that's all I have. Does it matter how long the connecting wires are?
P.s. my signal goes down considerably during a call. -69 to -90db! Just tested outside in my backyard.
Sent from my Sensation using XDA
yes, only a few miliamps. I've conducted some tests at hardware level for this. For example, the HD2 (latest phone i've test using this, here's the topic: http://forum.xda-developers.com/showthread.php?t=1018833 ) has a standby consumption of about 4-5mA (ranging from 0.2 - 6 mA). Standby means screen off, all wireless off (except gsm), processor in low power state. If i remove the antenna, the phone will still have about 1 line on the network signal indicator. Power consumption will increase with 2-3 mA. But that's about it.
The measurements are being done using a professional multimeter directly linked in series with the phone's battery.
The situation will be different if you use the phone in order to make.. phone calls. With full signal, once you make a phone call the phone's transceiver must begin to emit to a nearby carrier antenna, therefore a lot more power will be used. While having the screen off, consumption will jump from 2-3 mA to about 210-240mA during a call. If you have low signal, you can add another 100mA. (that's much...).
So if you make frequent phone calls or use the 3g networks all the time (always on type of connection) you will increase your power consumption with about 40-50%. Stand by and some rare phone calls won't have a noticeable impact, but actively using 3g and making phone calls.. well, that's another story.
Yes, it's normal for signal to drop a little when on a phone call, especially on poor carrier coverage areas. In fact, the signal is constant but your phone's RF transceiver is using very much power to transmit and due to something called supply voltage collapse (voltage drop occurring when a large amount of energy is being drawn from the battery) the receiving part will lose some of it's sensitivity.
2G signal is actually more stronger then 3G from the user's point of view. 2G was developed first, there are more 2g antennas then 3G ones, they covered a greater area with better antenna density. It's far easier and cheaper to build and install a 2g antenna then the more complicated 3G, 3.5G or 4G ones. 2G frequency emission require less power from both antenna and connecting phone then that of 3G.
as an interesting fact, a dual core cpu phone will have a maximum consumption of about 550-600mA. This is only occurring at full load (all wireless on, benchmarks, full screen brightness, etc). From a simple calculation based on the fact that this measurement was done on a 4V battery (about 60-70% charge) we can deduct that a modern phone consumes a maximum of about 2.2Watts
I have taken a metal plate and cut an opening into the middle that exactly fits my smartphone. When I put this on my desk and put my smartphone in the opening, I get three bars instead of one.
Forget it, it was a joke. I have not tried it, and it would most likely not work. But I am dreaming of it, because I have the same situation in my home office and at work—only one bar and a poor, slow, stuttering Internet connection.
I did try various things, like putting my phone into a ring of wire, but that did not work either. But one thing did work and has helped me—I searched and found the best position at work. There is one place on my desk where I consistently get about two bars, sometimes three. If I move the phone just an inch, reception gets worse.
The position seems to be stable. Rain appears to weaken the mobile phone signal generally, but the best position remains pretty much stable, so I don't have to repeat the search on my desk every day.
Of course the best place for mobile Internet and mobile phoning is at a window, like leaning the phone vertically against the glass pane. But that is usually inconvenient, out of reach, out of sight, prone to the phone falling down, too far away from the charger or from the computer, what have you.
The trick to find the best place for the mobile Internet is Settings, About phone, Status. This command shows, among other things, the strength of the received signal in dB and asu. For both numbers more is better, but the dB figure is negative, so there a smaller number is actually more.
I have not found any equivalent indication for the Wi-Fi signal strength. There may well be an app for that, but since I am actually looking for improvements that can be seen in the signal bars, I have not searched for that. One more bar is my aim.
So that is my recommendation for now: Search for the best phone position if you are in the same unlucky weak-signal situation like me.
But now back to the original question. Is it really not possibly to amplify the radio signal by using some passive piece of metal? It could be used like a reflector, for example, similar to the parabolic mirror of a satellite TV antenna. Or it could look like an antenna itself, attracting the radio waves to the nearby phone. I'd be interested in this for both the mobile Internet and Wi-Fi.
i've seen some kind of mettalic sticker that u put behind the cover of your phone on some website/forum, it says it can amplify the signal, i haven't tried them though
a.marduk said:
i've seen some kind of mettalic sticker that u put behind the cover of your phone on some website/forum, it says it can amplify the signal, i haven't tried them though
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That is snake oil. Any contraption that fits inside the phone cannot amplify the signal, because it cannot receive more radio energy than the built-in antenna. Or, in other words, if it worked, the manufacturers would all put it in already.
Theoretically it might be possible for a bigger structure to concentrate more of the radio signal onto the phone's antenna, but I have never found a solution, except for large devices that have to be put on the roof or on a mast. But even for those the advice is to prefer active ones, i.e. amplifiers.
hgmichna said:
That is snake oil. Any contraption that fits inside the phone cannot amplify the signal, because it cannot receive more radio energy than the built-in antenna.
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Not necessarily. Yagi antenna design uses directors and a reflector to amplify the signal to the driven/main element...yet they are not physically connected to that element.
At the frequencies used by cell phones, the directors/reflectors would have to be VERY close to the main element.
But placement is critical. Just slapping a contraption in the case would be hit or miss. Unless you knew where the antenna was and were able to place the decal properly in relation to that antenna, it might do nothing or even degrade reception.
hgmichna said:
Or, in other words, if it worked, the manufacturers would all put it in already.
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Actually, they do...sort of. The engineers who develop cell phones take the shape of the case and placement of components (including the antenna) into account. They have to: The device has to pass MANY tests to conform to FCC regulations (and other countries if they want it to be usable worldwide). The internal structure of the phone is designed to shape the radiated signal and conform to regulatory standards.
ssenemosewa said:
Not necessarily. Yagi antenna design uses directors and a reflector to amplify the signal to the driven/main element...yet they are not physically connected to that element.
At the frequencies used by cell phones, the directors/reflectors would have to be VERY close to the main element.
But placement is critical. Just slapping a contraption in the case would be hit or miss. Unless you knew where the antenna was and were able to place the decal properly in relation to that antenna, it might do nothing or even degrade reception.
[…] The engineers who develop cell phones take the shape of the case and placement of components (including the antenna) into account. They have to: The device has to pass MANY tests to conform to FCC regulations (and other countries if they want it to be usable worldwide). The internal structure of the phone is designed to shape the radiated signal and conform to regulatory standards.
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You are right. But then the Yagi antenna is a big thing that requires some space much bigger than the actual antenna element.
But I agree that, if the phone is in a particular position in relation to the tower and some piece of metal is perfectly shaped and placed, it may actually enhance reception a little.
In most practical cases this is difficult to accomplish. The phone is held in various directions, for example. I guess that placing the phone in an optimal place and position, like leaning it against a window pane, yields a better result without any special antenna enhancer element.
That's what I am actually doing with moderately good success. I will probably change providers soon though, which will yield a much bigger enhancement, as the new provider has a tower around the corner.
Well, since I had no intention of using the cellular function on my watch, I decided to attempt installing a normal watch band and I think that it all turned out nicely. Noting that this watch will accept a 22mm standard watch band, I first checked to see if a standard 22mm spring pin would fit and it did so nicely as far as the length goes. The holes that the screws fit through are much larger than the standard pin normally fits it so to keep the pin in place within the band you have two choices. Either use a standard pin and glue it into the band so it cannot slide in either direction or use a band that uses the quick release pins like I did. I used one of the "Milanese" magnetic bands that a quick release pin would fit into. It was one that I had already and I like the adjustability of it and it is black in color which matches the watch well. Now as far as the open slots where the original band's antenna connectors is concerned, I covered them with some tiny pieces of self adhesive thin craft foam that I got at a local Walmart in the crafts department. Two small rectangular pieces cut to fit worked very well to seal off the openings and it look like it was made to be there. It was a little tricky to install the band but it seems to fit very well and is very secure as well. Here is a link to just one of many of these bands offered on eBay. I would attach a picture of my LGWU2 with this band on and worn on my arm but I do not see a way to do that here.
** UPDATE... Well I just discovered that the antennas in the original band are not for the cellular service only. I was losing my Bluetooth connection only a few feet away from my mobile phone. WiFi seemed to work pretty much the same though. I thought this would be a good idea, but I guess not. Oh well.
graywoulf1 said:
Well, since I had no intention of using the cellular function on my watch, I decided to attempt installing a normal watch band and I think that it all turned out nicely. Noting that this watch will accept a 22mm standard watch band, I first checked to see if a standard 22mm spring pin would fit and it did so nicely as far as the length goes. The holes that the screws fit through are much larger than the standard pin normally fits it so to keep the pin in place within the band you have two choices. Either use a standard pin and glue it into the band so it cannot slide in either direction or use a band that uses the quick release pins like I did. I used one of the "Milanese" magnetic bands that a quick release pin would fit into. It was one that I had already and I like the adjustability of it and it is black in color which matches the watch well. Now as far as the open slots where the original band's antenna connectors is concerned, I covered them with some tiny pieces of self adhesive thin craft foam that I got at a local Walmart in the crafts department. Two small rectangular pieces cut to fit worked very well to seal off the openings and it look like it was made to be there. It was a little tricky to install the band but it seems to fit very well and is very secure as well. Here is a link to just one of many of these bands offered on eBay. I would attach a picture of my LGWU2 with this band on and worn on my arm but I do not see a way to do that here.
** UPDATE... Well I just discovered that the antennas in the original band are not for the cellular service only. I was losing my Bluetooth connection only a few feet away from my mobile phone. WiFi seemed to work pretty much the same though. I thought this would be a good idea, but I guess not. Oh well.
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Thanks for sharing, I had been thinking along the same lines as you and it seems you are 90% there, I have a few questions (and suggestions) that only you can answer
First - as far as I am aware the watch primarily uses wifi to connect to the phone, not sure if it is WIFI Direct or some sort of sharing through a shared router were both device need to be connected - not sure on this, if it is a direct connection to the watch then BT doesn't matter much.
Lets suppose you need BT to work.
So you plugged up the holes on each side of the watch which is fine and maintains its water resistance but and this is a big BUT, did you think of stripping the Connectors and antenna out of the original band and using them to plug the into the watch, you could then extend the antenna under your new band (out of site) and attach using glue or something, that way you plug the holes in the watch as intended with original connectors and also retain some of the connectivity, only you can answer this as I don't know exactly what room you have to play with, the old bands are useless anyway so maybe you could carefully strip out the bits needed to achieve this, you may only need to do it on the side that supports BT antenna
Just throwing ideas
forgot to ask
do you have a link to the bands you bought
Geoffxx said:
Thanks for sharing, I had been thinking along the same lines as you and it seems you are 90% there, I have a few questions (and suggestions) that only you can answer
First - as far as I am aware the watch primarily uses wifi to connect to the phone, not sure if it is WIFI Direct or some sort of sharing through a shared router were both device need to be connected - not sure on this, if it is a direct connection to the watch then BT doesn't matter much. Lets suppose you need BT to work. So you plugged up the holes on each side of the watch which is fine and maintains its water resistance but and this is a big BUT, did you think of stripping the Connectors and antenna out of the original band and using them to plug the into the watch, you could then extend the antenna under your new band (out of site) and attach using glue or something, that way you plug the holes in the watch as intended with original connectors and also retain some of the connectivity, only you can answer this as I don't know exactly what room you have to play with, the old bands are useless anyway so maybe you could carefully strip out the bits needed to achieve this, you may only need to do it on the side that supports BT antenna. Just throwing ideas. forgot to ask, do you have a link to the bands you bought
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Thanks for the suggestions on extending the antennas but in my case, my original band is in perfect condition so I am not willing to deconstruct it yet. Th thought of using parts from an old unusable band did cross my mind and I even put out some posts asking if anyone had a broken band that they wanted to give away or sell but I have not gotten any responses on that yet. The Bluetooth and WiFi both still worked but the range from my phone was about six feet at the most. I was nice to have a smaller and lighter band for a day but it just did not work out as far as getting notifications and weather updates while walking around the house. The link you asked about is https://www.tntkstore.com/lg-band-parts. I ordered a set of new screws for my band from them. They are in China but the delivery time was not bad at less than two weeks. They sell the most parts for this watch that I have found anywhere. The fact that LG has nor offers these bands and parts is an abomination in my opinion but I love the watch anyway.
I am very careful with my watchband and do not flex the ends any at all if I can help it. I have large wrists so I only connect to the second hole but when I am putting it on or taking it off, I try to pull it as straight and gently as I can. I plan on ordering an extra band to put back as an extra. I have gotten used to the bulkiness of the band now and I don't mind it at all anymore. I wish that there were other options for more flexible bands in different styles and colors though. I have attached a picture of what my watch looked like with a Milanese style magnetic band on it. I used small pieces of adhesive craft foam sheet to cover and seal the antenna connection ports. I hope I have helped in some way with this. Have a good day.
I can live with 6 feet lol or I might just buy a spare band, I am like you and will be careful, I think if I get 3 years out of the new watch I bought I'll be doing ok and might look for what's new at that time, TBH I would have bought the Samsung S3 Frontier if it had been AW - by far the best watch out there at the moment but we shall see when the time comes
Thanks for the link
I just upgraded from a Sony SW 2 which I had for years lol and also from an Xperia Z1 to a XZ2 Premium so new stuff all round and loving it
cheers my friend
check other thread
even though I was careful my band is failing and am in the process of fitting a 22mm stainless steel band, I only use and need BT so only one antenna will need to be retained (the BT antenna probably supports the wifi too)
check out the other thread I updated with photos