Wireless Hacks, 2nd Edition

Chapter 6. Do-It-Yourself Antennas

Hacks 83–93: Introduction

The price of wireless networking hardware has fallen dramatically in a very short time. Wireless adapters now come standard with many computers, and off-the-shelf access points are commonplace, making it easy for just about anyone to set up an off-the-shelf wireless network. However, the prices of antennas and related components have also fallen sharply as high demand and extreme competition have driven the industry to an increasingly high-volume, low-margin business.

These lower prices have enabled do-it-yourselfers to experiment and find out just how little it takes to build a working network. There is something almost magical about radio networking. Tales of war driving (and even war walking) aside, just imagine that today in many cities around the world, dozens of invisible networks exist on any given street corner. As you sit at a cafe eating your lunch, you might be completely unaware of the dozens of people simultaneously using the environment around you to communicate with people around the world. I believe that it is largely this mysterious, intangible aspect of unseen global communications that draws people to embark on their own antenna projects. The deeply rewarding feeling of making something useful out of virtually nothing is worth much more than saving a few dollars on an off-the-shelf network component.

When comparing antenna designs, there are a number of important factors to keep in mind. The first antenna ...