Wifi on the CHIP computer leaves something to be desired. While looking at switching to the Raspberry Pi 3 I found the onboard wifi on the Pi is not that great either. I did run across this information on 2 ideas to add an external antenna to the Pi.
https://www.dorkbotpdx.org/blog/wramsdell/external_antenna_modifications_for_the_raspberry_pi_3
It was submitted by wardr on Dorkbox PDX.