Since he's using the very new Buffalo 802.11 AC router, hey may be out of luck at this time. He can try using any range extender available, but it may not work with the new A/C wireless spec. Generally, Leo advises getting a Wi-Fi extender from the same manufacturer of the router, and as soon as Buffalo comes out with one for the new A/C spec, that's what he should get.
It could be that the laptop doesn't support WPA, but Brian says he can connect to his home Wi-Fi network with WPA just fine. The Fascinate may have limits on how many devices can connect to it, so he could try not connecting anything else to it at the same time. It's also possible that the phone is using 802.11n, but the older laptop doesn't work with that. He should also check if his phone is using the same security protocol, whether it be WPA or WPA 2, as his router at home.