Joe wrote:
Do cell phone boosters really work, or is it just more hype to get you to
part with your dollars? In an area where there are hills and valleys,
sometimes I can't get a very good signal in the valleys. It seems like I get
calls all the time when I am in an area of poor reception. Has anyone had
any experience with these?

Snake oil.

I suppose the idea is that the booster couples to the antenna, and
concentrates the phone's power along the horizon. That keeps you from
wasting power shot into outer space, making it more likely that power
will reach the base station. Same thing can happen in reverse: by
making the antenna more sensitive to signals arriving along the horizon
(where they come from) rather than those coming from outer space.
(where there are no base stationsgrin)

Problem is... that the design won't work.

The ones I've seen are designed to insert in front of the battery. This
location has a few problems:

- The battery, which is mostly metal, shields anything inserted in front
of it. Including the booster.

- Any metal in the phone (including the battery, and the original
antenna) affects the directivity of the booster - its ability to
concentrate power along the horizon. Since the booster is not directly
attached to the antenna, the metal in the phone also affects the
indirect coupling of the booster to the antenna.

Every phone is different. The size, the shape, how far the battery is
from the antenna, it's all different from phone to phone. This means
that a single booster design cannot possibly work with every phone.
There would have to be a specific design for your phone.

- In any case, the boosters I've seen don't match any valid antenna
design I'm aware of. (they really look a lot like the "laundry tickets"
we used to use in the dorms at the University of Wisconsin back in the
1970s!) (I wouldn't be too horribly surprised to learn they *are*
laundry tickets...)

It is certainly possible to build a cell phone booster. It would have
to be custom-designed for your phone. And most users would regard them
as impractically large and cumbersome. (probably not
eye-doctor-approved, they'd be a serious poking hazard!)
--
Doug Smith W9WI
Pleasant View (Nashville), TN EM66
http://www.w9wi.com