Additional, Perfect E use for the boundary which is orthogonal electric field , such as ground plane, metallic object. For HFSS, if you do not assign boundary on the outer surface, the software will automatic assign Perfect E.
for wilkinson power divider model, it is base on microstrip model. you can make the ground plane by selected once of below option:
- assign the bottom surface to perfect E or don't assign the boundary, for ideal design
Or
- assign the bottom surface to FiniteCond, If you know conductivity of object which touch the substrate.
Or
- make the sheet object and assign the metal meterial,such copper or brass or....or PEC . this option the result will close to real model if you assign the real metal.