We've had a LOT of fun (& publicity )here in New Zealand over DIY
antenna brewed up for 2.4GHz USB WiFi.See = www.usbwifi.orcon.net.nz
The parabolic Chinese cookware used gave ~15dB gain at 2.4GHz, but of
course any radiation will be concentrated at a parabola's focal point.
Aha - could suit "log cabin in the woods " cell phone boosting ?
Indeed it does, & 900/1800MHz GSM cell phone reception improvement has
also been verified when the phone is cradled at the FP.
Naturally you'll find it hard to speak at this position,unless perhaps
a Bluetooth headset used, but at least inward calls/text messages can
now be received. See = http://www.usbwifi.orcon.net.nz/cellbear.jpg
& http://www.usbwifi.orcon.net.nz/wokaxim.jpg

This sure beats constructing Yagis,& 12" woks here in NZ are just
~US$5! Stan ( ZL2AJZ )