this is my quad modified antenna with 2 front elements (reflectors). front elements are the same as antenna itself and are connected using copper wire - 3.1cm length.
antenna-router connection is using 50ohm rg174 coaxial cable - no more than 36cm length of cable (use 36cm or 24 cm).
antenna reflector is formed from 2-3 aluminium dishes - at least 20cm diameter.
the spacing between the antenna and reflector is about 1.6cm.
router settings (i use a tp-link 740n):
- wireless mode: "only n" or "only g";
- RTS threshold: 750;
- Fragmentation threshold:375;
- channel: 1;
- region: singapore.
for those of you with wrt54 g series: install dd-wrt and double the tx power. watch carefully for router overheating. if you are afraid of overheat, reduce tx power a little bit until you are satisfied.
using this antenna and these settings i am able to transmit outdoor wifi signal over aprox. 200m distance at a speed rate of 7-8 Mbps (aprox. 1 MB/s, or download a mp3 song in 4 seconds).
i believe that using 2 routers and two of this antenna with the same polarization and these settings, one can establish a reliable wifi link with at least 8Mbps over 1km distance.
of course, this antenna is very directional. the beam width is about 50-60 degrees.
i use this antenna in horizontal polarization (this is working best). for horizontal polarization place antenna vertically!