Asked Questions/ Technical Information
We at E-mobile provide you as best, a solution as
possible with all the testing, (former & continued)
customer data and research we have compiled for some
times selecting the right antenna for many people
is a bit of a guessing game. There are so many variables
that, it's difficult to determine what is going to
work best in all of the locations you live, work and
travel. Geographical layout, atmospheric conditions,
obstructions and operating frequencies are just a
few things that need be considered when choosing the
right antenna for the job.
many people have allowed the type of antenna they
"like" to be the deciding factor on what
they should purchase and not the "terrain"
of the desired application. This includes hidden,
portable, magnetic-mount on your car, glass mount,
pole mount etc. The lack of conclusive information
or knowledgeable advice on the part of many "cell
phone dealers" today, have not made things any
easier for the customer who needs to maintain a sure
link of communication on a daily basis.
have tried several options before finding something
that works for them while others are in locations
that nothing will help. We have provided this information
to help you understand a bit more why getting the
"right tool for the job" is so necessary.
times just selecting an antenna that is convenient
for the way you plan to use it (hidden, portable,
magmount on your car, glass mount, pole mount etc.)
works just fine. Most customers use the few tips we
have here and select an antenna that works for them
on the first try. A few customers have tried several
options before finding something that works for them
while others are in locations that nothing will help.
We have provided this information to help you make
an educated guess on what type of antenna might work
What does Omni directional mean?
It means that the antenna will recieve signals from all
possible directions for the mobile phone to work at its
best. The original mobile phone stub antenna is nothing
but an Omni antenna. (Followed by Image with Phone
& Internal Stub Antenna)
What is dB gain?
Gain is defined as the compressing of the vertical component
of the antenna pattern, in effect causing the radiation
pattern of the antenna to reach out further toward the
horizon. It is not the creation of power, but rather a
simple refocusing of energy from all directions to a specific
direction. Gain is measured in decibels (dB). Vertical
antennas are in fact quite directional, except in the
horizontal or azimuth plane.
What is the difference between dBd & dBi?
Gain can be expressed in many different ways. The two
most common are dBd and dBi. Gain expressed, as dBd is
a measure referenced to a half wave dipole. The dBi measure
is referenced to a theoretical, dimensionless point source
with a completely spherical radiation pattern. Since it
has no directivity, any real antenna without excessive
loss will provide some amount of gain when compared to
the isotropic. E-MOBILE antennas are all rated in dBd
What's the difference between 0db (unity), 3db, 6db gain?
0-dBd gain antenna radiates more energy higher in the
vertical plane to reach radio communication sites that
are located in higher places. Therefore they are more
useful in mountainous and metropolitan areas with tall
buildings. A 3-dBd gain antenna is the compromise in suburban
and general settings. A 5-dBd gain antenna radiates more
energy toward the horizon compared to the 0 and 3 dBd
antennas to reach radio communication sites that are further
apart and less obstructed. Therefore they are best used
in deserts, plains, flatlands, and open farm areas.
My Mobile phone shows 1 or 2 bars but I still can't make
a call. Why?
Although the phone shows some signal, it isn't strong
enough to make a connection due to congestion in the network.
I can sometimes make a call but at other times I cannot
connect at all. What do you recommend?
You might just need a little help. Try a Omni
Power Antenna. Search for your phone's make and model
(using the menu on the left) to see if one of these kits
is available for your phone.
I live in a rural area and have to travel a Km. or two
from home to be able to make a call on my phone, will
an antenna help?
An antenna might help. If you're in an area with large
hills or mountains, it's most likely nothing will help.
But if the terrain is flatter, we would recommend a Omni
Power Antenna or a Yagi
antenna. The 6db is easier much easier to set up than
the Yagi and most people get great results with one. Analog
phone and service is your best bet in rural until more
digital towers are installed. A Yagi antenna is your best
bet in rural areas alongwith a very high pipe or a tower
taking full advantage of height.
I used to be able to make calls with my old phone from
home but now I can't make any with my new phone.
An Yagi Antenna
will help, If your old phone was a GSM phone with a Stub
Antenna and a External Antenna Adapter you have the advantage
of an Antenna Adapter which would physically connect to
your mobile phone without any signal losses. However,
with the new trendy phones, most of which have internal
antennas and no sockets for external antenna the only
way out to connect an External Antenna is by using a Plastic
Adapter which is not so efficient as compared to the older
connector. Here the signal transmitted from the external
antenna to the mobile phone is indirect and therefore
only 80 to 90% efficiency is achieved.
I want something portable that will improve my signal
strength and I can use in my home or office.
Try the Omni Power Antenna
with the 2.5 metre cable.
I want an antenna that I can hide. What do you recommend?
In reality there are sticker Antennas available in the
market costing from 50 to Rs. 500/- and improving the
signal from 0 to 3% only, which is negligible as compared
to our Omni Power Antenna giving 80 to 100% increase in
signal strength. Our company believes in delivering real
quality and performance and therefore we only deal in
Omni & Yagi Antennas.
How do I connect an external antenna to my phone?
You can connect most phones to an external antenna by
using an installable hands free kit that comes with an
external antenna adapter. You can also purchase an external
antenna adapter that allows you to connect the antenna
directly to your phone. Some phones have an external antenna
port. Other phones require that you remove your fixed
antenna and insert an external antenna adapter to that
port. Still other phones have no way to connect an external
antenna to it at all. Read
Can I improve my signal without connecting an external
antenna to my phone?
Not to our knowledge.
Reception is poor inside my home or office. Can I use
an antenna made to mounted on a car?
Yes, most cellular and digital antennas are manufactured
for use on cars and trucks. The car or truck acts a ground
plane for the antenna. To get the most from your antenna,
you should supply a ground surface if using the antenna
away from the vehicle. Many of our customers have had
good success using these car antennas inside their home
without a ground plane but we recommend providing a ground
plane such as putting the antenna on top of a piece of
metal (about 8 inches x 8 inches would be fine) and placing
outside or near a window.
I'm in a basement with no windows. What are my options?
Some of our customers have seen increases in signal strength
by just connecting an antenna to their phones and placing
the antenna as high as possible. We would recommend getting
it as close to the outside as possible without adding
to the cable length.
I need an antenna with a 100 foot cable?
Adding to the cable length will greatly reduce the signal
getting to your phone. As a general guide, you'll lose
about .1db gain for each additional foot of cable with
analog networks and .15db gain in digital. You'll also
lose about .1db gain for each additional connector you
use. You will compulsorily have to use the 15db High Gain
How does a glass mount antenna attach to the glass?
One portion of the antenna is glued to the outside of
the glass and another is glued right behind it on the
inside of the glass. The signal is transferred through
Since the glass mount antenna has to transfer the signal
through the glass, does that mean it is not as powerful
as the magnetic mount antenna?
No, the glass antennas are rated passing the signal through
I have window tint on my rear window. Will this interfere
with the antenna?
If metal is used to tint the glass, it will interfere.
Many professional installers will cut off a piece of the
tint so that it does not interfere with the antenna.
Drill a hole… Not on my vehicle! What options do
"On-Glass" antennas are easy to install and
do not diminish a vehicle's value by drilling a hole.
Care must be taken during installation to ensure that
the antenna is mounted high up on the glass and not over
defogger wires or on reflective window tint and this could
"Rear-Dash" is also another option, however
performance losses will occur. "Magnetic-mount"
This step-up, allows the easy placement and removal of
your antenna on the rooftop of your vehicle. Very useful
for multiple vehicle applications.
Where should I place my antenna?
In applying all the information provided for the maximum
benefit of the radiating pattering of your antenna it
would be wise to position the whip as vertically and as
high as possible.
If the antenna
is tilted, some of the signal will be wasted because
it will be directed up to the sky or into the
If the antenna
is much lower than the vehicle's roof, the signal
will be blocked and the radiating pattern will
customers may direct any further questions to: firstname.lastname@example.org
Can I use a Vehicle Magnetic Mount antenna anywhere else?
Yes, most magnetic mount cellular antennas are manufactured
for use on vehicles, as the roof of the vehicle acts a
ground plane for the antenna. However to get the most
from your magnetic mount antenna, you should place it
on a metal ground surface when using the antenna away
from the vehicle. These antennas work great indoors once
a sufficient ground plane is provided, such as placing
the antenna on a filing cabinet or on a piece of metal
(about 8 inches x 8 inches) and placing it outside or
near a window.
You can experience choppiness in the audio even when your
signal indicator is reading 2 or 3 bars.
are presently in the market for a new phone, our advise
to you is to ignore the hype surrounding the technologies
and look at service provider instead. Judge each with
an eye to price, phone choice, coverage, and reputation.
Technology should play a very small roll in your choice,
as the products we carry at E-mobile will more than likely
overcome any of those problems. If you follow this advice,
you'll probably be much happier with the phone and service
you inevitably wind up with.
External Antennas connected to portable cell phones, (CDMA
and GSM) greatly increase signal output, or propagation
to the cell site tower. The improvements in signal pattern,
strength, and effective range can be dramatic. Using an
external antenna adapter will allow connection to any
external antenna. The portable phone can be connected
to an antenna on top of the car, SUV or even a filing
cabinet at the office. Or connect to a marine antenna
up 20 feet on the boat. Or connect to a directional
antenna outside the home or factory to beam to a distant
cell site. Plus, battery power is extended and radiation
is kept away from the user. Below, in various paragraphs
are the details wanted by users so they can also improve
their antenna performance.
PERFORMANCE WITH STANDARD ANTENNA
Most phones on the market today may have a very well designed
antenna on top of them but they are usually performing
with a gain of -3 to as much as -15, that's negative 3
to 15 dBd using a dipole or quarter wave as rough reference
point. The lower number could be the phone as a stand
alone item and the highest negative numbers come when
the phone is in your hand and one inch from your head.
Not to mention the radiation pattern which is far from
omni-directional, PLUS the polarization is not vertical,
which is what the cell site prefers. And don't forget,
on top of all that you may be inside a metal roofed car!
As we can
see, signal propagation off the top of a portable phone
can be pretty bad. Fortunately though most users are working
well with on-phone antennas because of the supreme cellular
coverage enjoyed in the US and some other highly developed
countries. Today, cell sites are covering the land and
providing a nice blanket of signal coverage. BUT, there
are lots of exceptions to this good coverage.
The antenna placed away from the phone and in the clear
will provide enough performance to increase usable distance
between 2 and 50 miles. Small 3" tall magnetic (0dB
gain) antennas are at the low end of this distance estimate
and 8-element Yagi directional (10dBd) can be at the high
end. See the Yagi tech
info page for more info on those. While the Yagi or
Panel antennas are for fixed locations and provide terrific
gain in one direction, the popular external antenna is
a magnetic based or glass mounted antenna on the car.
This type will be address here.
never really state an exact distance increase because
it is all very dependent on conditions that are changing
constantly. For example cell-site tower distance, site
antenna height, design, type of terrain and placement
and efficiency of the external antenna. We can safely
say that, the external antenna will provide a vertically
polarized, omni-directional signal at 0 (zero or unity)
gain up to 7dBi (6dBd) which will be a noticeable and
effective signal increase. Depending on the phone and
what antenna is used outside the car, signal improvement
should be on the order of 6 to 20dB less approximately
1 dB for cable losses to the antenna. This equals, anywhere
from triple to 5 times the power (on the horizon) that
was being radiated by the phone-top antenna!
ANTENNAS: AUXILIARY ADVANTAGES Health Benefits
Use of an external antenna will keep the signal radiation
away from you. Instead of radiation 1" from your
head (ruining the signal pattern) you will be sending
your signal out to where it works best. This also addresses
the safety concerns of radiation so close to the head.
the external antenna can greatly increase battery life!
Your phone has 7 output power steps. It is instructed
by the cell site how much power to put out between approximately
1/20th of a watt to the full power 6/10ths of a watt.
If you are using the external antenna in a moderate to
good signal coverage area, your phone will power down
because of the increased antenna efficiency.
The best way to get the signal out of the portable phones
is by using the manufacturer's "Car Kit" or
"Hands Free" kit selecting the model with RF
out or RF interface for antennas. Sometimes the RF version
costs substantially more or is not offered, or the user
wants total freedom instead of placing the phone in a
cradle or holder. AlternativeWireless.com carries cables
(external antenna adapters) which can connect directly
to the phone. These cables, approx. 8" - 24"
thin cable where one end plugs into the phone's antenna
and the other end provides a popular coaxial connector
(TNC, FME, Mini-UHF are examples) receptacle to allow
a thicker, lower loss cable going to the cellular antenna,
to be connected. The thinner 1/8" (RG-174) cable
near the phone allows free movement and is not as restrictive
as the 3/16" (RG-58) cable supplied with most antennas.
ANTENNAS: AVAILABLE CONNECTIONS
Some phones have the tiny "coaxial" jack as
part of the multi-pin connector block inside the bottom
of the phone. Our connector will plug into that and use
only the coaxial pin while the other pins are blank and
not used. In this case you would not be able to connect
another one there to access audio, charging or data pins.
For some phones we offer a combination charging/antenna
plug as a unit. But remember, external antenna usually
means longer battery life due to lower RF output in moderate
to good coverage areas. Phones in this category are the
families of Nokia 2120/2160 etc., Mot StarTAC, Elite,
Ericsson 738, Sony 100 etc.
type of output on phones places the RF jack all alone
usually on the back near the top but it can be on the
bottom or side near the bottom. This stand-alone RF jack
will not interfere with the multi-pin at the bottom. Examples
of this are the Ericsson 300 or 600 (non retractable antenna
types) and the Nokia 6100/5100 series.
page for more information on the cellular phone antenna
that's right for your situation.