These files are used for
Simulation
Use this part of the tutorial to simulate the RF performance of your
circuit.  You need to include the lengths of all lines (including the pads
for soldering elements to).  These are found in the layout section, so
you will do some back-and-forth between layout and simulation.
Some elements are available in the standard libraries (the cap in this
lab), others are not (the diode in this lab).  When they are not available,
you will have to “create” them using user-defined S-parameters and
lines (MLIN).  These can come from data sheets (like the HP website)
or from measurements (like for this lab).