If your OK with the possibilty of ruining the phone!
... you can try to solder a short pigtail of coax to the antenna points you see
in the phone. Put a BNC on the end of the pigtail and use this to connect any
type of experimental antenna you like.

I dont know about in the Phillipines, but most cell phone operate on several
frequency bands, so the antenna is a compromise. If for instance the frequencies
are 900mhz and 2400mhz then you need to force the phone to operate on say 900
then attach a properly tuned antanna for 900mhz. Likewise for 2400mhz. A
resonant half wave dipole for 900 mhz will be about 33cm (or a quarter wave
vertical would be about 16cm tall with radials of 16cm). Directional antennas
would be better but they are more critical to build and adjust.

One way to solve your problem might be to sit on the roof to talk, that way you
get gain by your height.

Another way might be locate the phone up high, and use a remote headset, and use
voice commands to dial out. You still get the benefit of height but can stay
inside.

You could put the phone in the focus of a corner reflector or parabolic dish
pointed at the cell tower. The phone is the radiator and the dish gives you
gain. This is probably the ideal setup if you are stationary in not mobile.

Note: Any time you try to remote the antenna you need a length of coax between
the phone and the antenna. At these frequencies, 50ft of even excellent coax
(1/2" diameter) will likely completly ruin any gain the antenna may give you.
You would only be eliminating some sources of noise by getting up away from the
house. Directional antennas give +gain and the neccessary coax gives -gain but
hopefully not as much, so you come out ahead.




"yhan" wrote in message
ups.com...
greetings,

i am trying to build an external antenna for my cp. i have found
serveral programs from the net about antenna designing so i might try
them but my problem is this, how will i connect the coax cable to my
cell phone. it does not have a whip antenna. when i opened the case i
found a metal in the upper back portion of it. this is maybe the cell
phone's antenna. so is there a way i can connect my external antenna to
this type of cell phone? what is the impedance of a cell phone because
i read that the impedance of the antenna and the feeding device should
be same. any suggestion would be greatly appreciated.

thanks in advance,

ian
philippines