DEP Model using Comsol 4.3

Hello,
I am trying to do a DEP simulation in Comsol 4.3 and I want to apply an AC signal of 10V 14KHz in a pair of electrodes. I am presently using AC/DC model. I am able to apply a DC signal but I am not getting the AC signal.

My question is how can I apply an AC signal in those pair of electrodes? Because I am not getting any procedure to apply AC signal in Comsol.

Please help me, my complete project depends on this.