Generally with AMS Designer (along with the digital simulation tools, such as ncvlog, ncsim etc) it requires you to have
an hdl.var file in one of a number of search locations
(typically your working directory).

You don't need that much in it. Usually something like
this will suffice:

Code:

SOFTINCLUDE $AMSHOME/inca/files/hdl.var
# setup use5x by default
define ncuse5x
define cdslib ./cds.lib
 

You might set up the path to transistor models if you're
simulating at transistor level, although this can be
done through the UI now with AMS Designer.

Andrew.