Cell Phone Geometry

Ijust purchased my first Smartphone and, as a result, have been fascinated by all that it can do. I became interested in the way it works, and, in the process, I discovered some very interesting applications of the geometry many of us teach.

What particularly interested me was how cell phones transmit and receive. I have often wondered about the antennas like the one in Figure 1 that have sprouted up all over in the past ten or so years. I wondered why they aren't taller, why there are so many of them, and why many have the triangular shape that has become so common. This column is an attempt to answer some of those questions. For those of you interested in how cellular technology evolved over the years, go to [3].

A cell phone is actually a miniature radio that both transmits and receives.