AnsweredAssumed Answered

Optimization directly to standard component values

Question asked by JERRY_MARKETOS on Sep 6, 2005
Latest reply on Mar 16, 2008 by MZachmann
Optimization directly to standard component values - some notes-

Users often have first impression that the optimizer uses the tune increment
set in the "Tune" window, but this is not the case.  The optimizer uses its own
independent increments during the course of its operation, and in fact the increment
size decreases as the optimizer believes it's nearing satisfaction of (or closest to)
the optimization targets.

We understand the desire for optimization directly to standard component values,
however this endeavor is much more complicated than it might appear.  Optimization
to standard component values necessarily introduces a new requirement beyond the
other requirements (optimization targets) that already exist, and this necessarily
introduces a conflict among competing requirements.  (If it didn't, the numbers would
have come up coincidentally at standard values in the first place, and we know how
rarely this occurs !)

Proceeding...  When sets of conflicting requirements exist, the solution most always
involves a tradeoff.  For instance, let's say a chosen tuned parameter ends up approximately
in the middle between the two closest standard values...  Choosing the higher standard
value versus choosing the lower standard value will often involve a tradeoff in measured
performance parameters, perhaps for instance better return loss vs insertion loss closer to spec.
The user's presence is required in order to make those tradeoffs according to whichever
performance parameters are most critical.

Going just a bit further- sometimes even when a particular value ends up NOT mid-way
between the adjacent standard values, (ie. closer to one of the standard values...)  The
first tendency is often to choose the closest standard value.  However, subsequent work
may reveal that the best choice isn't the nearest standard value, due to other compromises
made as other components are steered to chosen standard values.  Again, transition to
standard component values is a step that requires user decisions according to what are
the critical performance parameters and tradeoffs.

This is a time when we're often thankful that we have modern EDA tools that allow
us to view the tradeoffs virtually as fast as we can press the keys.

By the way....

Did you know that when tuning with Genesys....

You can tune element values using the mouse to click the
little up and down arrows for each tunable element in the "Tune" box.  (This is the slow way !)


You can tune elements using the keyboard   PAGE UP   and  PAGE DOWN  buttons
to do the same thing.

You can also use the keyboard arrow keys to index up / down through the list of tunable elements
shown in the TUNE box.  Spend a minute or two orienting your right hand to where the
PAGE UP  PAGE DOWN and arrow keys are on your keyboard, and you'll be able
to tune multiple elements up and down at a very fast pace with Genesys.