In order to significantly boost the performance and range of a Wi-fi router, which has only internal antennas, you need at least 5dBi external wi-fi antennas
, as the internal ones are usually just 2-3dBi:
(2 x 5dBi antennas and 2 adapters), which cost a lot less:
Long story short, the DIY part of the upgrade requires you to make holes on the router's case for the adapters and connect or solder the smaller plug in the right place on the logic board.
For the TP-LINK TL-WR720N V1.00
i had to remove the internal mini-antenna, cut the adapter's small plug and solder the cable directly in the antenna's place on the board:I used one 5dBi antenna, as this router only supports one. Honestly I didn't get any speed improvements in the room, but in the bathroom and backyard I got a significant signal boost. Even though the wall is 30cm thick and made of full bricks, I get full signal strength and speeds around 70Mbps download and 25Mbps upload (this is the maximum upload speed of my internet connection). Before I installed the antenna, I used to get 2-3 bar signal strength and around 34Mbps download / 14Mbps upload speed.
Even though this is a significan improvement, it's not the best way to achieve it, in the sense that the TL-WR720N V1.00 router is not the best candidate for this upgrade. V2.00
has been out for quite some time, which has a preinstalled external antenna and in fact costs less...The antenna upgrade makes sense only if you have a very good router, which meets all your needs, except for the Wi-fi signal strength and speed. The same goes for access points and USB adapters - you can buy really cheap ones with strong external antennas, but if you already have a good one, it may be worth your while to upgrade the antenna(s).
NOTE: keep in mind that for different frequencies and standards you may need different kinf of antennas: 2.4GHz vs. 5GHz; N standard vs. AC standard ....etc.