Wireless Hacks

Deep Dish Cylindrical Parabolic Reflector

This simple design provides high gain without pigtails or modifying your AP.

I needed a parabolic reflector to eliminate off-property coverage. This design can reduce signal from some areas while enhancing signal in other areas. I designed this reflector to be installed in outdoor enclosures with WAP-11 access points, but it is becoming quite popular with people building indoor LANs, as well as with people building very short point-to-point links. This design offers very high performance and easy availability (scissors, tape, cardboard, tin foil, and 20 minutes, and you are in business). See it in action in Figure 5-1.

Figure 5-1. Add a reflector without modifying the AP.

This antenna is so easy to make, tune, and install, and it performs so well, that it is foolish not to try one before electing to purchase a commercial antenna, if for no other reason than you can check to see whether you are purchasing enough commercial antenna gain to make the link you want to make.

Advantages over other antennas:

• No pigtail [Hack #66] required

• No modification to AP (no voiding of warranty)

• No matching (SWR) problems

• No purchased parts

• Trivially easy construction

• Very low probability of error

• As good as or better performance than the Pringles can antenna [Hack #72]

• Superior front-to-back/front-to-rear ratio

• Improves wireless LAN privacy

• Reduces interference

This ...