Design & Build Better Cell Phone Antenna?

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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




Re: Design & Build Better Cell Phone Antenna?
On Mon, 8 Apr 2013 10:41:19 -0700 (PDT), snipped-for-privacy@yahoo.com wrote:

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What model LG phone?  Which service provider?  You can compare
received signal strength and other useful numbers by putting it in the
"field test mode".
<http://www.wpsantennas.com/pdf/testmode/fieldtestmodes.pdf

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Good luck.  When the FCC decided that SAR (specific absorption rate)
was a design requirement, the antenna was moved from an external
projecting rod, to an internal pretzel like contrivance.  In addition,
the addition of 4G data frequencies, has added yet another antenna to
the phone.  The resulting antenna tends to be at the BOTTOM of the
phone, usually under your hand.  The RF spews mostly from the back of
the phone outward, and away from your head.  Try holding the phone
with two fingers and the hand away from the bottom.

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There are various cell phone boosters and repeaters available.  They
are only really useful for vehicles and buildings.  It might be
possible to add an antenna to your unspecified model cell phone, but
that would require an external antenna jack.  Few phones have those
these days.  

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It's fairly simple.  Find where the antenna is located on your phone.
Built a coupling loop or patch antenna to cover the built in antenna.
Connect the coupling loop or patch antenna to a suitable antenna.
Kinda like this abomination for the iPhone 5 wi-fi range problem:
<http://www.absolute.com.tw

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Design & Build Better Cell Phone Antenna?

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<
http://802.11junk.com/jeffl/coverage/VZW-water-plant/850Mhz-2watts-39dBu.jpg

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I have local cell site locations compliments of the county planning
department.  Your ability to obtain those will largely depend on
convincing them that you're not a terrorist, eco-activist, or
professional protester.  

I also built a really awful cell site direction finder.  The receiver
is just a cavity band pass filter, MMIC broadband amp, and diode
detector.  With all the power a typical cell site spews, there was no
need for elegance.  I could have used commercial ceramic filters, but
I had the cavities handy.

The antenna is the real trick.  It's just a vertical monopole,
sticking out through the center of rotating plywood disk.  Over the
monopole is either a horn antenna, or a half-parabolic reflector.
Elegance and gain are not as important as directivity, pattern, and
beamwidth.  

I eventually plan on using a PPI (plan position indicator) radar type
display, but for now, an oscilloscope will suffice.  There's a
mechanical dead ahead marker on the rotating platform which goes to
the Z axis (brightness) input and the sweep trigger.  When the peak in
the sweep coincides with the bright dot, the antenna is pointed
directly at the source of RF.  At this time, it only works on the
1900MHz PCS band.  I was thinking of adding a telescopic sight, but
that might attract too many questions from the authorities.

I could post photos of the prototype but as I plan to eventually turn
this into a product and since the antenna design has some cute tricks
to obtain narrow beamwidth, I'll pass.  You could probably build
something from my description.  Bug me if you need help.  Happy
T-hunting.

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They have never been in the FCC data dumpster.  Cellular allocations
are by market area.  It's up to the various providers to decide the
location of their towers.  The >200ft mega towers can be found in the
FAA databases.
<https://oeaaa.faa.gov/oeaaa/external/portal.jsp
Lots of errors and omissions in both the FCC and FAA databases.  
You can get shopping lists from the various tower leasing companies
(AT&T, Crown-Castle, American Tower, Sprint, etc) all of which have
web sites.  There are also rooftop leasing companies with similar
lists.  Those are easy compared to finding all the antennas in a DAS
(distributed antenna system).

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Yep.  This is as close as I can find to something accurate:
<http://www.antennasearch.com

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Congrats on re-opening the AGPS can of worms.  AT&T started out using
E-ODT using the tower locations and TDOA (time difference of arrival)
to locate cell phones because it didn't require a phone with a built
in GPS receiver.  Somehow, they met the FCC requirements.  However,
subsequent tests and a few incidents demonstrated that it didn't work.
So, AT&T is slowly moving towards A-GPS/AFLT (assisted GPS / Advanced
Forward Link Trilateration), which has been in use by Verizon and
other since about 2001.  
<http://birds-eye.net/definition/acronym/?id11%65798855
<http://en.wikipedia.org/wiki/Assisted_GPS
A-GPS doesn't really need for the site to broadcast it's exact
position because the real position is already stored in the location
service provider database.  No computation is done in the phone.
Instead, the phone sends the raw GPS satellite  timing data, the cell
site number, and the TDOA (ping results) to the cell site, which
passes the data to the service provider via the internet.  The data is
processed by a computer, and the final lat-long is returned to the
PSAP (public safety answering point) or to the phone if the subscriber
pays for the service.

I'm not sure why AT&T cell sites spew lousy location information.  My
guess(tm) is that they don't really care because the information isn't
used by A-GPS.  Verizon is no better for the same reason.  I've
noticed that most of the newer VZW sites don't broadcast their
Lat/Long. There are some Android apps that produce numerous screens of
CDMA data including the tower locations.  These look promising:
<https://play.google.com/store/apps/details?id=jp.maruse.cellinf
<https://play.google.com/store/apps/details?id=kenyu73.realsignal
Look for BSID (base station ID), BSLAT, BSLONG (Lat/Long).  Argh.  The
first one is producing ID's, but no Lat/Long info.

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Nice.  I don't have one (yet).  So many projects, so little time.

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
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Re: Design & Build Better Cell Phone Antenna?
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."  Li
ke this idea want to keep things simple.

Searched the forum using "coupling loop" and found a 1999 post "Energy-suck
ing radio antennas!" https://groups.google.com/forum/?fromgroups =#!search
in/sci.electronics.design/%22coupling$20loop%22/sci.electronics.design/cBLf
oRXSN7U/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  Progress
 In 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"   h
ttp://www.hard-core-dx.com/nordicdx/antenna/loop/inducloop.html
For AM radio  

"coupling loop for loop antenna bu Jim" http://www.radiobanter.com/showthre
ad.php?t74%935  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. C
hiu and C.-H. Chang" http://www.jpier.org/PIERC/pierc16/12.10072503.pdf

Finally found "Printed Coupled Loop Wideband Antenna Design for Wireless Co
mmunication" http://www.techrepublic.com/whitepapers/printed-coupled-loop-w
ideband-antenna-design-for-wireless-communication/32879207  but was unable  
to DL.

Probably the best I have found to date is "Patent application title: Loop a
ntenna 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 l
ike an antenna.  If you tell me where to send or how to post will send phot
o.  

Probably more informative would be parts breakdown for LG3320G but have not
 yet found it.

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

Hope a DIY Loop Antenna will do better.

Thanks again for your help!!!

Ken










Re: Design & Build Better Cell Phone Antenna?
Hi Miso,

Thanks for your suggestions and links.

Ken

Re: Design & Build Better Cell Phone Antenna?
Hi All!

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

First I'd like to say thanks for using my program! I'm aware of the glitche
s you mentioned, but couldn't find any "cleaner" way to do it, so that's ju
st 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 leav
e it like that for a while. I'd like to add LTE to it soon, so I may get ba
ck to work on it sometime this year.

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

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

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=============
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 receptio
n, 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)

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

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===============
Thanks again for using my app. I actually built in in 2008-2009 as an exper
iment on my Nokia N95 phone. I built it to use for myself originally, but t
hen decided it would be cool to open it up to the public to see everyone el
ses coverage plots as well. It's coming up on 1 million points soon, I'm gl
ad to see people all over the world have found it useful for various purpos
es :) 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, s
o it's an interest of mine.

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

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

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 a
nd 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 a
pp. That's the total received signal power, interference and all.

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

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g>
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.jpg>

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=================
That's a nice plot, what open source software did you use to make that? Mos
t simulation software (like TEMS) is usually very expensive. Also, how do y
ou determine what transmit power and antenna gain to use?  



Re: Design & Build Better Cell Phone Antenna?
On 4/10/2013 11:02 AM, info% snipped-for-privacy@gtempaccount.com wrote:
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you mentioned, but couldn't find any "cleaner" way to do it,
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just got it working to a point where it was working
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to it soon, so I may get back to work on it sometime this year.
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CDMA is a little better). If you want a budget GSM phone
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or femtocell (but you'd have to get an
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experiment on my Nokia N95 phone. I built it to use for myself
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see everyone elses coverage plots as well. It's
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have found it useful for various purposes :)
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definitely not in it for the money ;)
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it has alot of interference or not).
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transmit level should be. SNR plays a factor, but signal loss does as well.
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That's the total received signal power, interference and all.
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<
http://802.11junk.com/jeffl/coverage/VZW-water-plant/850Mhz-2watts-39dBu.jpg
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simulation software (like TEMS) is
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antenna gain to use?
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The open source way to make such plots is with radiomobile or splat!
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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.

Re: Design & Build Better Cell Phone Antenna?

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antenna gain to use?
Quoted text here. Click to load it

The open source way to make such plots is with radiomobile or splat!
Quoted text here. Click to load it
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.

Re: Design & Build Better Cell Phone Antenna?
On Wed, 10 Apr 2013 11:02:28 -0700 (PDT),
info% snipped-for-privacy@gtempaccount.com wrote:

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<
http://802.11junk.com/jeffl/coverage/VZW-water-plant/850Mhz-2watts-39dBu.jpg

For your amusement, I usually work on the cellular providers side of
the approval process.  This time, I'm working for the residents of the
neighborhood where Verizon wants to plant a tower.  The first URL is
based on my version of the MPE (max permissible exposure) numbers for
24 hour exposure.  Verizon also claimed that the site is necessary to
fill in gaps, but the 2nd URL shows that about 90% of the strong
signal coverage area is duplicated by other local Verizon cell sites.
When Verizon saw that there was organized opposition, they had the
item temporarily withdrawn from the city council agenda.  

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Back around 2001, I was involved in the fabrication of a tower
ordinance for the county.  As part of the exercise, I made a map of
the existing cell towers in Santa Cruz County, and started adding
coverage plots:
<http://802.11junk.com/cellular/index.html
I didn't get very far doing only one site:
<http://802.11junk.com/cellular/jeffl/SVLY-PGE/index.html
I then ended up dropping the project due to medical reasons, and never
went any further.  Information as to cell site locations can usually
be obtained from the county planning department.  Ours was initially
rather reluctant.  My initial locations came from a photograph I made
from a printout supplied by the county during the tower ordinance
proceedings:
<
http://802.11junk.com/cellular/Wireless-Cell-Sites.jpg

After an exchange of legal mumbo-jumbo, I prevailed and received a
nice spreadsheet with existing structures, lat-longs, and also planned
cell sites.  The locations were horrible.  I had to visit each site to
get an accurate GPS location as well as the correct altitude and
antenna details.  Google Earth is usually good enough to get a
location if you can see the structure on the image.  

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simulation software (like TEMS) is usually very expensive. Also, how do you
determine what transmit power and antenna gain to use?  

There's some more plots under:
<http://802.11junk.com/jeffl/coverage/
They're mostly ham radio repeaters and point to point links.  My
clients don't want me posting their stuff on the internet.

I use Radio-Mobile:
<http://www.cplus.org/rmw/english1.html
0.3 arc second SRTM elevation data:
<http://www.cplus.org/rmw/dataen.html
and Google Earth.
<http://www.google.com/earth/

Radio-Mobile will automagically download any SRTM maps that are
needed, but I prefer to have them saved on my hard disk as it speeds
up the program.  Radio mobile creates a flat projection that is used
as an overlay in Google Earth.  I then add roads and boundaries in
Google Earth.  This can also be done inside Radio-Mobile, by
overlaying with maps from various online map sites.  You can see how
it works, by downloading (for example):
<
http://802.11junk.com/jeffl/coverage/VZW-water-plant/Picture1.jpg

<http://802.11junk.com/jeffl/coverage/VZW-water-plant/Picture1.kml
and putting them in the same directory.  Double click on the KML file
and it should start Google Earth.  After it's up, step on the middle
mouse and move the mouse around.

I don't want to spend the time right now outlining the exact order and
procedure for producing a decent coverage maps.  I had planned to do a
web page in preparation for a song and dance on the topic for the
techy part of our local radio clubs, but I don't have the time.  Bug
me if you want a rough explanation.  There are quite a few tutorials
for using Radio-Mobile on the web.

--  
Jeff Liebermann     snipped-for-privacy@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
We've slightly trimmed the long signature. Click to see the full one.
Re: Design & Build Better Cell Phone Antenna?
 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+%C2%A3100  

Ken  



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