It's probably a little larger than you want, but last year I bought a "CSL - USB 3.0 SuperSpeed Wireless AC1200 Dual Band network adapter with 2 x 5 dBi detachable antenna " which has a Realtek RTL8812AU chipset. I just installed it again to check whether it works at 5gz. It does. But it wasn't plug and play and I had to install the drivers using these instructions:Already been there and done that , Plenty of support for 2.4 GHz but 5 GHz seems a bit flaky so i was hoping for personal experiences...