history/background:
as u know, directional antenna r gud at point-to-point connectivity. this can be translated into two things:
i. capturing (or stealing) signal from far away (usb wifi can also do this), or
ii. bridging/joining two networks from two different buildings (u'll need a router. not actually any router)

i gave up with the commercial antennas mostly because of their prices & the cable they used. i believe most of these cables r only suitable for hi-power, industry-grade APs whatsoever, not the type of routers that we r familiar with. what sux even more is the cable's price. if u r buying a high power outdoor antenna, i think 1/4 of the price r for that lousy cable. so goal no.1: eliminate the use of pricey low-loss cables. goal no.2: off course, try to make my own antenna.

i've tried 'pringles antenna' and the 'original cantenna', but not satisfied with the result. i realised that even tho we can construct our own antenna, there must be some sort of 'rules' we can follow in order to make the antenna more efficient. i study around looking for a 'formal & serious' guide on how to built these antennas. these 2 sites r my main references:
http://www.saunalahti.fi/elepal/antenna2.html
http://www.wb8erj.com/wirelessCantenna.html

if u read thru these guides, u'll know why the pringles & cantenna aren't so efficient.

how do they work?
all these antennas uses the same concept. they will concentrate ur signal strength to a certain direction/angle onli..

this is actually a half-directional and half-omni antenna. good for home use, especially if u want to control ur signal from flowing to ur pesky neighbours. i've constructed and used these in my hotspot, however those r just using alumunium foil. the one i'm selling uses alumunium, for longer lasting. and can fit routers with up to 2 antennas.
p/s this thing may look stupid, but u'll be surprised by its performance.

based on the traditional can-antenna (made from can/tin). however the old cantenna have lots of weakness, and i tried to rectify all those weakness in my design. this thing is suitable for uni students. nowadays most uni have wifi, but those r primarily for outdoor usage onli (the signals cant get thru walls). for indoor, u might want to try one of these. very 'mobile'.

yup, the improved version of cantenna. several sites did mentioned that the cantenna can be improved by adding a bigger head at the end, however most of them never say how to do it. luckily i found one.
from my testing, the bazooka have the same range with cantenna, however with a better reception. biggest problem is its size. if u plan to move ur antenna a lot, better use cantenna.

the most powerful of them all. the feeder of this parabolic antenna is actually a cantenna. output from the cantenna will be boost-ed again by the parabolic dish, so u got urself a double-boost! this antenna r popular in indon, they called it wajanbolic. however i find their design is not yet optimized. they didn't bother bout the length of the feeder which is quite important.
got 2 problems:
i. not easy to mount a router with this thing
ii. will have problems with wind