The ex2200 has no wireless capability so your only option is to connect via ethernet.
I don't follow exactly how the three devices are being connected to create the layer 2 loop. Since you have two devices and the ex switch I assume you will use the bottom example in the Deco doc. In that format there is a single connection between each pair and no loops.
If you create a layer 2 loop topology for some kind of redundancy then you will need to enable some version of spanning tree on the devices to prevent the loop and block the redundant ports until needed during a link failure.