Design & Build Better Cell Phone Antenna?

[[email protected]]

Have a new small LG cell phone that has worse coverage than older larger cell phones.

If I could, would exchange my LG for another cell phone with better coverage.

I am not an antenna designer but have lived in marginal FM & TV areas where a simple improvement in antenna made a significant difference in reception so would like to design and build a better antenna for my cell phone.

Am interested in any suggestions or comments by anyone (especially someone who has actually done this).

Thanks

Ken

 

[miso]

I can't believe the iphone needs that junk.

If you want signal strength, use the app at www.cellumap.com. You get
the signal strength at the phone and tower. You can also upload it to
the database if you want to provide the data for public consumption. The
upload includes rather detailed information about your phone, and of
course the location. Best not to upload the data at your house or any
place where you wouldn't want to be know to frequent (McDonalds, dive
bars, whore houses, crack houses, the Apple store, places like that.)
Because the 'hits" are very specific, it is possible to identify each
user. Then if you click at your house, you are totally tagged.

My impression is the developers kind of got bored with the project.
There certainly are improvements that could be made. For instance, in
the boonies, where you are likely to roam, it would be nice to see any
specific type of signal (i.e. all GSM or all CDMA), and then figure out
if you have the right to roam on that network. For instance, T-mobile
could be using AT&T,Cellular One, etc. The database has a few bugs in it
in that some of the hacked Android phone OSs show up as networks. For
example

http://www.jellybombdomination.com/

But in any event, the app is great for reading signal strength, even if
you don't upload.

I have noticed that the OS can alter the signal strength of the phone.
That is, the OS can change the decision criteria for power level. So an
upgrade of the firmware can change the situation.

 

[[email protected]]

Hi Jeff,

"What model LG phone?" LG 320G

"Which service provider?" TracFone using AT&T network

"Built a coupling loop or patch antenna to cover the built in antenna." Like this idea want to keep things simple.

Searched the forum using "coupling loop" and found a 1999 post "Energy-sucking radio antennas!" https://groups.google.com/forum/?fr...i.electronics.design/cBLfoRXSN7U/c9nlBn-lGuoJ

Did a quick read but not fully understand the technical.

Googled and found some more recent hits

"PDF] A Miniature Coupled Loop Antenna to be Embedded in a ... - Piers
https://piers.org/piersproceedings/download.php?file... by SY Lin ProgressIn Electromagnetics Research Symposium Proceedings, Xi'an, China, March 22–26, 2010. 721. A Miniature Coupled Loop Antenna to be Embedded ..."

"Inductively Coupled Loop Antenna By Werner Funkenhauser and Pete Haas" http://www.hard-core-dx.com/nordicdx/antenna/loop/inducloop.html
For AM radio

"coupling loop for loop antenna bu Jim" http://www.radiobanter.com/showthread.php?t=74935 For FM radio

Also checked Loop antenna Wiki http://en.wikipedia.org/wiki/Loop_antenna

Decided to narrow my search to coupling loop antenna "cell phone" and found"A MEANDERED LOOP ANTENNA FOR LTE/WWAN OPERATIONS IN A SMART PHONE C.-W. Chiu and C.-H. Chang" http://www.jpier.org/PIERC/pierc16/12.10072503.pdf

Finally found "Printed Coupled Loop Wideband Antenna Design for Wireless Communication" http://www.techrepublic.com/whitepa...na-design-for-wireless-communication/32879207 but was unable to DL.

Probably the best I have found to date is "Patent application title: Loop antenna for cell phone having a metallic or non-metallic casing by Chi-Ming Chiang" http://www.faqs.org/patents/app/20100087235#ixzz2PzBb7hYT

Also took the back of the LG320G off but did not see anything that looked like an antenna. If you tell me where to send or how to post will send photo.

Probably more informative would be parts breakdown for LG3320G but have notyet found it.

Thanks for the link. After viewing the video decided to check if anyone had reviewed it and found "Absolute Linkase Review by Lisa Eadicicco on April5, 2013...The Verdict: Absolute's Linkase iPhone 5 case sports a sleek andfashionable design, but doesn't do enough to improve your phone's Wi-Fi signal."
http://www.laptopmag.com/reviews/accessories/absolute-linkase.aspx

Hope a DIY Loop Antenna will do better.

Thanks again for your help!!!

Ken

 

[[email protected]]

Hi Miso,

Thanks for your suggestions and links.

Ken

 

[miso]

I've only tested one iPhone 5. The wi-fi range sucks compared some
other PDA's and smartphones that I've tested.

Photo of wi-fi antenna in the iPhone 4:
http://guide-images.ifixit.net/igi/diPxJJbPrKTKJUSq.huge
and iPhone 5:
http://guide-images.ifixit.net/igi/bytbI1dmCgHYoOmb.huge


I've been using it erratically for about a year on my Droid X.
Although the phone section is not activated, it reports cellular
signal strength via Wi-Fi. The problem is that I can see reports
around common gathering spots, such as coffee shops, but nowhere else.
Looking at the Santa Cruz area for Verizon, there is exactly one
signal report, dating back to July 2012, apparently from my Droid X.
The next closest report is in Mtn View. Yech.

Yes, unless people play the game, crowd sourcing doesn't work. I upload
AT&T reception via wifi at coffee shops just to be nice.

Anyway, I prefer to run my own numbers. For example:
<http://802.11junk.com/jeffl/coverage/VZW-water-plant/Picture11b-3D-03.jpg>
<http://802.11junk.com/jeffl/coverage/VZW-water-plant/850Mhz-2watts-39dBu.jpg>

If you have tower locations, you can make those maps. I have open source
software to do it. The problem is you don't always know the tower
locations and possibly the roaming partners in the boonies. Cell towers
are no longer in the FCC database, or perhaps don't have to be in the
FCC database is more correct since some towers do show up. All those
sites on the sides of buildings are handled by a general FCC
authorization where if the local municipality is OK with the site, then
that is all it takes to put it up. So in an urban area the vast majority
of cell sites are not documented in the FCC database.

This guy started a database, but hasn't updated it in years:
http://sfocellsites.com/

Google has a database of cell sites that you can access through a API,
but it so full of errors that it is useless. I have another app to get
this information, but it is not worth the effort due to the poor
accuracy. To be specific, poor accuracy in GSM type towers. CDMA towers
supposedly report their exact GPS locations. Why the hell GSM doesn't do
that is a good question. So with the proper app, you could get all the
CDMA tower locations.

If you have a rtlsdr (and I bet you do), you can search for LTE signals
and then get signal strength.

https://github.com/Evrytania/LTE-Cell-Scanner

You can also detect the frequency error of the rtlsdr using the LTE
tower as a reference. The 700MHz band LTE can be found, but the dongles
quit around 1760 or so, which is not high enough to get the T-Mobile LTE
carriers.

 

[info%[email protected]]

Hi All!

=================

My impression is the developers kind of got bored with the project.
There certainly are improvements that could be made. For instance, in
the boonies, where you are likely to roam, it would be nice to see any
specific type of signal (i.e. all GSM or all CDMA), and then figure out
if you have the right to roam on that network. For instance, T-mobile
could be using AT&T,Cellular One, etc. The database has a few bugs in it
in that some of the hacked Android phone OSs show up as networks.

=================

First I'd like to say thanks for using my program! I'm aware of the glitches you mentioned, but couldn't find any "cleaner" way to do it, so that's just kind of how it is. I haven't gotten "bored" with the project, I just gotit working to a point where it was working pretty good and decided to leave it like that for a while. I'd like to add LTE to it soon, so I may get back to work on it sometime this year.

PS- It's just me so it's "developer" in the singular term

==============

"What model LG phone?" LG 320G

"Which service provider?" TracFone using AT&T network

=============
I think we found the problem LG makes really bad GSM/UMTS phones (their CDMA is a little better). If you want a budget GSM phone with good reception, get a Nokia, or Motorola. Otherwise look into a repeater, or femtocell (but you'd have to get an AT&T subscription for that to happen I believe)

==============

I've been using it erratically for about a year on my Droid X.
Although the phone section is not activated, it reports cellular
signal strength via Wi-Fi. The problem is that I can see reports
around common gathering spots, such as coffee shops, but nowhere else.
Looking at the Santa Cruz area for Verizon, there is exactly one
signal report, dating back to July 2012, apparently from my Droid X.
The next closest report is in Mtn View. Yech.

Unprofitable exercises have the bad habit of doing that to developers.

===============
Thanks again for using my app. I actually built in in 2008-2009 as an experiment on my Nokia N95 phone. I built it to use for myself originally, but then decided it would be cool to open it up to the public to see everyone elses coverage plots as well. It's coming up on 1 million points soon, I'm glad to see people all over the world have found it useful for various purposes The app is free and the advertising barely pays for the server, so I'm definitely not in it for the money I am a cellular network engineer, so it's an interest of mine.

===============

I hadn't noticed that, but I'll look for it. As I understand how it
works, the SNR at the cell site determines the power per channel. With
CDMA, if there are more phones in range of a cell site, the base line
noise level goes up. This causes the cell site to assume that the
signal from your phone is fading, and compensates by increasing its
power output. That might be what you're seeing. There's also the
side effects of CDMA cell site "breathing", where the coverage area
changes depending on site loading:

================

SNR is "Signal to Noise Ratio" and tells you how "clean" the signal is (ie:if it has alot of interference or not). The "Power control" in the phone and base station determines how much the transmit level should be. SNR playsa factor, but signal loss does as well.

RSSI (Receive Signal Strength Indication) is what's shown in the Cellumap app. That's the total received signal power, interference and all.

================

Anyway, I prefer to run my own numbers. For example:
<http://802.11junk.com/jeffl/coverage/VZW-water-plant/Picture11b-3D-03.jpg>
<http://802.11junk.com/jeffl/coverage/VZW-water-plant/850Mhz-2watts-39dBu..jpg>

If you have tower locations, you can make those maps. I have open source
software to do it.

=================
That's a nice plot, what open source software did you use to make that? Most simulation software (like TEMS) is usually very expensive. Also, how do you determine what transmit power and antenna gain to use?

 

[miso]

Hi All!

=================
=================

First I'd like to say thanks for using my program! I'm aware of the glitches you mentioned, but couldn't find any "cleaner" way to do it,
so that's just kind of how it is. I haven't gotten "bored" with the project, I just got it working to a point where it was working
pretty good and decided to leave it like that for a while. I'd like to add LTE to it soon, so I may get back to work on it sometime this year.

PS- It's just me so it's "developer" in the singular term

==============



=============
I think we found the problem LG makes really bad GSM/UMTS phones (their CDMA is a little better). If you want a budget GSM phone
with good reception, get a Nokia, or Motorola. Otherwise look into a repeater, or femtocell (but you'd have to get an
AT&T subscription for that to happen I believe)

==============


===============
Thanks again for using my app. I actually built in in 2008-2009 as an experiment on my Nokia N95 phone. I built it to use for myself
originally, but then decided it would be cool to open it up to the public to see everyone elses coverage plots as well. It's
coming up on 1 million points soon, I'm glad to see people all over the world have found it useful for various purposes
The app is free and the advertising barely pays for the server, so I'm definitely not in it for the money
I am a cellular network engineer, so it's an interest of mine.

===============


================

SNR is "Signal to Noise Ratio" and tells you how "clean" the signal is (ie: if it has alot of interference or not).
The "Power control" in the phone and base station determines how much the transmit level should be. SNR plays a factor, but signal loss does as well.

RSSI (Receive Signal Strength Indication) is what's shown in the Cellumap app. That's the total received signal power, interference and all.

================


=================
That's a nice plot, what open source software did you use to make that? Most simulation software (like TEMS) is
usually very expensive. Also, how do you determine what transmit power and antenna gain to use?

The open source way to make such plots is with radiomobile or splat!

http://www.qsl.net/kd2bd/splat.html
http://www.cplus.org/rmw/english1.html

However, you don't always know where the tower is located. Or if you do
know where the tower is located, you don't know about the cell on the
side of a building, i.e some place where a tower wasn't erected.

I leave cellumap hits quite often. I was at a place where GPS use was
not allowed, so I left a cellumap hit just for the lols. Cell phone use
wasn't banned, just GPS.

I don't know if you saw my post, but the cellumap web interface could
use an upgrade. Often I want to see ANY service, rather than specific
service. That is, I may need a burner phone for a certain region, but I
don't know the carrier. Presently you have to pick the carrier on the
webpage, then look at the map. So it would be nice to show all GSM or
all CDMA. Then you could contact your carrier to see if you can roam there.

I used the Fairview app, but they got bored and dropped it. The nice
thing about fairview is you could keep the hits on your phone. It would
be nice if cellumap could do that, then upload later. I would force my
phone to competing networks just to get the data, then upload when I was
back on a network where I had service.

The only other alternative to cellumap is opensignal, but their maps
lack the data to back up the signal strength. For instance, if an iphone
has poor reception, that doesn't mean my phone will have trouble. In
fact, I've gone to spots where the cellumap showed poor reception and
left a hit showing the area is just fine.

 

[miso]

That's a nice plot, what open source software did you use to make that?
Most simulation software (like TEMS) is
usually very expensive. Also, how do you determine what transmit power and antenna gain to use?

The open source way to make such plots is with radiomobile or splat!

http://www.qsl.net/kd2bd/splat.html
http://www.cplus.org/rmw/english1.html

However, you don't always know where the tower is located. Or if you do
know where the tower is located, you don't know about the cell on the
side of a building, i.e some place where a tower wasn't erected.

I leave cellumap hits quite often. I was at a place where GPS use was
not allowed, so I left a cellumap hit just for the lols. Cell phone use
wasn't banned, just GPS.

I don't know if you saw my post, but the cellumap web interface could
use an upgrade. Often I want to see ANY service, rather than specific
service. That is, I may need a burner phone for a certain region, but I
don't know the carrier. Presently you have to pick the carrier on the
webpage, then look at the map. So it would be nice to show all GSM or
all CDMA. Then you could contact your carrier to see if you can roam there.

I used the Fairview app, but they got bored and dropped it. The nice
thing about fairview is you could keep the hits on your phone. It would
be nice if cellumap could do that, then upload later. I would force my
phone to competing networks just to get the data, then upload when I was
back on a network where I had service.

The only other alternative to cellumap is opensignal, but their maps
lack the data to back up the signal strength. For instance, if an iphone
has poor reception, that doesn't mean my phone will have trouble. In
fact, I've gone to spots where the cellumap showed poor reception and
left a hit showing the area is just fine.

 

[[email protected]]

Hi info%radio,

"LG makes really bad GSM/UMTS phones" Agree!

"If you want a budget GSM phone with good reception, get a Nokia, or Motorola."

Any model recommendations?

Any recommended Cell Phone websites?

Did a search and found http://www.trustedreviews.com/Nokia_mobile-phones?Price[]=Under+£100

Ken