Shielding a signal with both GND and supply?
Regions of metal will attract electric fields.
If the VDD and the Ground are not moving, there will be some (a lot, if this is wide metal) shielding.
For planar structures, the shielding by co_planar metals improves as the CUBE of the size of the un_moving regions.
Thus 10u + 1u + 10u, should be much much better shielding than 1u + 1u + 1u.
Howard Johnson awake me to this method, with his &quot;Digital Black Magic&quot; books of 20 years ago. Visit his website.
Also you can model this, as coupling between point charges as angles become flatter: there is an inverse_cubic relationship.