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pss/qpss in the same run (alter? in ADE L?)

itos

Hi,

I simulate a mixer and I would like to obtain values for NF and IIP3 at the same time.

NF is obtained using pss+pnoise. For this analysis only one periodic signal must exist (the LO) and the port of the input signal must have zero frequency/power.

IIP3 is obtained using a swept qpss+qpac. Apart from the LO, the input port must contain a nonzero frequency signal.

The stupid way is to change the schematic for each analysis. To avoid that, I created a design variable tran_in_enable and set the frequency and amplitude of the input port to tran_in_enable*fin and tran_in_enable*Pin. In ADE L, I the set tran_in_enable to 0 and run pss/pnoise to get the NF and in the next step set it to 1 and enable qpss/qpac to get IIP3.

However, I want to obtain both values in one shot. Now I learned about the alter statement. If I manually change my input.scs the following way, everything works as expected:

simulator lang=spectre
global 0 vdd!
include "models.scs"
parameters  tran_in_enable=0
[...]
simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 temp=27 \
    tnom=25 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
    digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
    checklimitdest=psf
pss  pss  fund=1G  harms=50  errpreset=conservative  annotate=status
pnoise  (  vop  vom  )  pnoise  sweeptype=absolute  start=1k
+       stop=BW  dec=10  maxsideband=10  iprobe=PORT0  refsideband=-1
+       annotate=status

alter1 alter param=tran_in_enable value=1

sweepqpss  sweep  param=Pin  start=-60  stop=40  lin=100  {
  qpss  qpss  flexbalance=yes  oversample=[1  1]  funds=["LO"  "fin"]
+     maxharms=[3  3]  errpreset=moderate  annotate=status

  qpac  qpac  start=1.09G  clockmaxharm=2  annotate=status
}
[...]

However, ADE L always overwrites the alter line.

What is the correct approach to run pss/qpss simultanuously in ADE L?

Thank you!

Parents

  • Thanks. hb+hbac+hbnoise does not seem to suffer from this problem.

    However, for the IIP3 curve I need to sweep hb+hbac over the input power Pin. If I also enable hbnoise, the hbnoise is executed for all swept Pin, resulting in huge computation time. For hbnoise, I only need to execute it once (for an arbitrary Pin).

    Generally, I'm not sure if this really fixes the general problem. What if I need to use shooting engine rather than harmonic balance?

    EDIT: I just saw your second response :)

    The problem is I am using this with Muneda wicked (a tool for circuit optimization) and this requires to obtain all outputs using the same netlist/run.

    I'd be very happy if Andrew has an appropriate hack for this.

    (On a note: I would find it very useful to have a special "Analysis" "alter" which can be freely shifted within the analysis box. Also being able to define multiple analyses of the same type would be very useful: then I could define "hb1" as a swept variant followed by "hbac" and then "hb2" without sweep, followed by hbnoise)

Reply

  • Thanks. hb+hbac+hbnoise does not seem to suffer from this problem.

    However, for the IIP3 curve I need to sweep hb+hbac over the input power Pin. If I also enable hbnoise, the hbnoise is executed for all swept Pin, resulting in huge computation time. For hbnoise, I only need to execute it once (for an arbitrary Pin).

    Generally, I'm not sure if this really fixes the general problem. What if I need to use shooting engine rather than harmonic balance?

    EDIT: I just saw your second response :)

    The problem is I am using this with Muneda wicked (a tool for circuit optimization) and this requires to obtain all outputs using the same netlist/run.

    I'd be very happy if Andrew has an appropriate hack for this.

    (On a note: I would find it very useful to have a special "Analysis" "alter" which can be freely shifted within the analysis box. Also being able to define multiple analyses of the same type would be very useful: then I could define "hb1" as a swept variant followed by "hbac" and then "hb2" without sweep, followed by hbnoise)

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