I learned that Wi-Fi range extenders, repeaters, and amplifiers are all different and use different technologies. From first hand experience, using any of these that take an existing weak wireless signal and send them out again will result in poor performance. Not only will the packet need to travel twice over wireless, but you can not get faster than where you place your wireless amplifier/etc device. If your router does not support WPS (like my Verizon router), you will end up with two network SSIDs, a nuisance.
The best solution by far for getting a stronger signal in somewhere else in your house besides running new Ethernet cables is using Powerline technology. It sounds sketchy but it is anything but sketchy. It actually uses the existing electrical wiring in your house to act as Ethernet cable, hence making any electrical outlet a possible Ethernet wired connection and second Wi-Fi hotspot.
My results using the device below were 30 Mbps up/ 30 Mbps down when plugged directly into the router. When two floors up and across the house, I received 27/27. Rather impressive.
TP-LINK TL-WPA4220KIT: http://www.amazon.com/gp/product/B00HSQAIQU/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1