The answer is yes.  Find an Intel AC card that is the same size that you need in your xps. You can buy it on Amazon. I did it, and I believe it was the 7260 that I purchased.
My Dell Studio XPS 1645 has a  Dell 370 Broadcom Bcm92046mpcie M980g Wpan 370 Mini Pcie Bluetooth card and a  94312HMG card. What is needed to up grade it to 802.11ac Do I replace both? Is the intel 7260 HMWWB 80211.AC comptible with my system? Pete  
Can I upgrade my Studio XPS 1645 to 802.11ac?