I have four differential transmission lines imported from Allegro layout into Momentum. So, 32 ports referenced to "Gnd" show up: 16 diff. pair terminating "signal" pads/ports and 16 "Gnd" terminating pads/ports in layout after importing. I usually go through manual process of pairing of each "signal" pin with its closest "Gnd" pin in the "S-parameter ports" pane on the right in the emSetup window; this lets me create 16 single-ended ports for Momentum simulation (I group them into differential ones in the Schematic window later). I do this by dragging in this pane a "+" pin that belongs to a Gnd pad in layout from its port in this pane to the "-" part of the other port with a "+" "signal" pin. Every time after this action, the S-parameter port tree collapses (pins hide), so I must expand the tree in order to grab the next pin and drag it to its destination. This is kind of painful. Also, if the destination port is not in the view, I drag the pin to the bottom border of the pane until needed port shows up. The pane content scrolls quickly. If I am lucky, I stop when the needed port is in the view and drop the pin into is place, and it replaces the "-" Gnd. If not, I have to scroll in opposite direction. The scrolling is difficult to control. It has been like this in ADS versions 2009, 2011, 2012, 2013. Is there a simpler way to do this pin pairing?