Spacing in a edge-coupled bandpass filter?

Hi,

I'm trying to design an edge-coupled bandpass filter. I've found Zoe, Zoo, W, and L. The only thing I'm having trouble with is finding the spacing. Is there a tool in ADS that will calculate this or is there a formula I have to use?

Use Tools > LineCalc > Start LineCalc and select Component MCLIN (for microstrip) or SCLIN (for stripline and enter the required substrate parameters and frequency on the left. Then in the center you can either enter W, S and L and analyze the structure to get ZE, ZO, Z0 etc. or enter ZE, ZO, Z0, etc. and synthesize the structure to get W, S and L.