Can the Wifi frequencies be seperated on an Arcadyan Gateway?

Open the phone app and tap the Network tab at the bottom. Tap the network name you're looking to split. First, change the network name on the first line to something you’ll recognize for your 2.4 MHz network, e.g., MyNetwork2. From the next menu, tap Frequency Band and choose 2.4 GHz. Then scroll to the bottom and tap Save. Your gateway will reboot and you will now have the first of your networks set.

To create your 5 GHz network, once again go back to the Network tab, but this time choose the “+” sign at the bottom. Create a new network name, e.g., MyNetwork5, then replicate all the same settings of your first network except to choose 5GHz as the frequency. Scroll to the bottom, click Save, the gateway will reboot and you'll be all set with your two networks separated.

Good luck!