Upgrading the Airport Card in MacBook Air 2012

Hi, I was just reading some reviews of the 2013 Macbook Air 13" and as an owner of the Macbook Air Mid 2012 (13"), the only thing I feel I am missing out on is the 802.11ac Wifi.

I have seen some of your guides on upgrading the card in a Macbook 13" (White) and replacing the Airport card in my notebook, but is it possible to purchase an 802.11ac card, as used in the 2013 model and replace my current 802.11n card to gain the benefits of improved connectivity?

Thanks,

Bob

Device Spec: Mid 2012 Macbook Air 13", 1.8GHz Intel i5, 4Gb DDR3 1600MHz, 128Gb SSD.