MacBook Air WIFI card Upgrade?

Apple hasn’t made anything newer for your system: 802.11ac Wi-Fi (802.11a/b/g/n compatible). It’s a single antenna design supporting both 2.4 & 5.0 GHz band streams.

While your card may have issues I’m thinking you have something else going on here.

Let’s see what network you are connecting to Vs your Dell. It maybe your Mac system is connecting to a 5.0 GHz Access Point (AP) while your Dell is connecting to a 2.4 GHz AP. The 5.0 GHz band allows more throughput but its not effective connecting through some wall types so if your AP is located at a distance or blocked by walls you can encounter issues unlike 2.4 GHz band.

It’s possible the AP your Dell is connecting is physically closer to you and as this AP is not able to support 5.0 GHz the Mac is connecting to a further AP.

It’s even possible both AP’s are able to support 5.0 GHz but for some reason your Mac is connecting to the more distant AP.

I know that’s a bit confusing ;-{ Basically, the connection is not sound vs having a hardware issue within your system.

OK so how do I figure this out?? First know your AP names! Ao if you have two or more routers give them unique names based on where they are in your home Basement, 1st floor 2nd floor etc… Now the tricky part! Your AP’s likely support both bands but you may hookup to the wrong band! So to make this more visible rename the AP’s bands so as an example the 2.4 GHz is called 1stFl_2-4 and the 5.0 is called 1stFl_5 so when you look at your systems WiFi connection info pane you know which you hoped up with as your system can’t tell the difference between the two bands 1st_floor and 1st_floor names!

To compare your signal strength, click on the WiFi icon in your menu while pressing the Option key so you can see the signal info