My design is about a directional coupling. I put probes in the exit door to get the power, but I need it normalized. I put the expression

 mod1.PN=(mod1.ewfd.nPoav/(mod1.bnd1+mod1.bnd2))

Where PN is the normalized power the bnd1 and bnd 2 are the test points, are calculating the output power at ports 4 and 3 respectively

But yielded no result.

If someone can give me a suggestion I'm grateful.