Applying a +/- 10 V sinusoidal signal to electrodes in air

Hi there

Been playing around with COMSOL in an effort to learn how to use it.

I have some success modelling my little arrangement with the electrostatics module:

a row of electrodes in the middle, surrounded essentially by a cage of ground electrodes that are 30 mm away (imagine a rectangle, with some electrodes in the center then grounds around the perimeter).

Now what I want to do is switch the electric potential signal I had, for one you might get out of a signal generator. Namely a 10 V (20 V peak to peak) Sinusoidal signal of a frequency of my choosing. How do I actually implement this now?

Do I need to change from electrostatics to electromagnetic waves from the RF-module? Or do I stay with electrostatics and do a frequency domain study?

I did try doing electromagnetic waves, but it only allows you to specify an electric field strength (V/m) and a frequency and anyway, I ended up with an error about the relative error being greater than the relative tolerance. What ever that means.

Any help would be much appreciated!

(I can attach the file later if necessary, I am not actually near the computer with the model on at the moment)