Momentum imprt need help

Dear friends,
I want to import PADS gerber to momentum for simulation.I met a problem that unit convert.In pads2007,i select mm or inch(as attached),generate garber.But when i import them to momentum,i found some cases:The copper layer size is correct,but the drill is always inch.So the drills look smaller as photo.How can i fix the problem?
Thanks for your kindness in advanced,

It might be that the drill file is calling out the dimensions... I'm not sure, haven't tried to read the raw Gerber text before. I have similar issues when importing some old designs into ADS Layout. By default the Layout editor uses mils, but the drawing is scaled in inches, so the resulting imported polygons are 1000 times too small. To correct this, I simply select all, Edit, Scale (somewhere in there), and tell it 1000x in X and Y, and viola! You could do the same thing here... since it's mm, and you want inches, the scale factor should be 25.4 or 1/25.4, since 1 inch = 25.4 mm. Measure a distance between a few known vias in PADS, and compare it to the length in ADS layout. You should be able to determine the scale factor pretty easily.

Thanks for enjunear's kindness.I will make a try.Another question,Any tool can help me that can import gerber and drill into Momentum，so that i cannot align copper layer and drill layer again?as we know it is not easy case for 8 layers drill draw.

I don't know of any tools that will do that. You're best option is to figure out which settings in ADS Layout are causing the import to come in with different units. You might try changing the default units on a blank layout, then import the drill layer, and see if that allows you to import millimeters as "millimeters" (instead of inches).

Another method would be to use alignment reticules/reference marks on your original design. Each layer would have an identical reticule, in the same location (like 0,0). You could use a mark off the corner of the design-space, like a + or X. Then, when you import all the layers, you can do a Select All on Layer, and snap the reticules together. You could delete the reticules before fabrication, or use them for mask alignment in the fabrication process.