Has anyone here used Superspice ?

I am looking for some information regarding setting up the Simulation
parameters to view Phase and Magnitude response for an oscillator
circuit (I have opened up the feedback path to enable a signal to be
injected through the amp and resonator.

I cannot find what I want in the documentation that came with the
software and the company has not replied to my email so I am hoping
someone else may be able to help.

Alternately if you know of a shareware or freeware simulator that could
I could use that has plenty of forum support ?

The exercise is to work through the book I have on computer simulation
"Oscillator Design and Computer Simulation" by Randall Rhea and see if I
can get the same results from the examples he gives (the version of his
book I have is the very first book sold and the software he used that
comes with the book is on an old disk I cannot read).

I have RFSIM99 but cannot see if I can get phase and magnitude
responses, I can get magnitude OK but want to have phase information
together with this to observe what the relationship is between them at
any given point.

Being "green" with regard to simulation, I do not want to purchase a
commercial simulator until I have some experience and am confident I
will be able to use it to obtain meaningful results.

Thanks in advance.

You might want to consider using LTSpice. Oscillators are documented
and the forum support on the Yahoo group is top notch. The program is
available from Linear Technology as a free download (with regular
updates).

URL is: http://www.linear.com/company/software.jsp

Good luck - Roger

Thanks. That software does the trick. My results are now similar with
the text example.

I downloaded the program and managed to get it running immediately
without documentation. Just need to figure out how to
load the S parameter file for my device now instead of preselecting one
of the models they give in the list.

wrote:
You might want to consider using LTSpice. Oscillators are documented
and the forum support on the Yahoo group is top notch. The program is
available from Linear Technology as a free download (with regular
updates).

URL is: http://www.linear.com/company/software.jsp

Good luck - Roger

"David" wrote in message
...
I downloaded the program and managed to get it running immediately without
documentation. Just need to figure out how to
load the S parameter file for my device now instead of preselecting one of
the models they give in the list.

SPICE doesn't know anything about S parameters... you need a linear RF
simulator to deal with them (and guess what? Randy Rhea, the guy who wrote
your book, was the original designer of Genesys -- that's where all the
screenshots in the book come from). With straight SPICE, the traditional
approach is to curve-fit a rational polynomial to the S parameters and then
use the polynomial directly (most simulators these days have a "Laplace"
operator) or systematically turn it into a bunch of controlled sources along
with RLCs that mathematically implement the same thing.

I believe that RFSim99 might work for you here...

---Joel Kolstad

I don't know exactly what you are trying to get the phase information
for, but RFSim99 can certainly display phase information for either or
both of its ports; it acts like a vector network analyzer. Just select
phase on the graphical display. It's in the pulldown menu on either
side of the graph window. Alternatively, you can save the results as
an S-parameter file.

With respect to using S-parameters in Spice, you should be able to
convert them to the domain that Spice understands with no trouble, at
least for discrete frequencies. It's more difficult if you need to
come up with a physical model that yields the desired S-parameter
performance over a range of frequencies. That's one of the really nice
things about RFSim99: you can instantiate a one-port or two-port that
uses an arbitrary set of S-parameters versus frequency. (Beware,
though, that the two-port model assumes a common terminal between the
two ports. And I've had trouble in the past trying to get an ideal
transformer give isolation; it seemed to want to assume the non-dotted
pins were both grounded. Try for example simulating port 1 feeding the
dotted pin of one side, the non-dotted grounded, and the dotted pin of
the other side grounded and the non-dotted pin feeding port 2. S11=0,
S21 = -208dB.)

It's good to keep in mind that S-parameters and RFSim99 deal only with
linear circuits. If your circuit is nonlinear, you should plan to use
the time-simulation capability of Spice (or use some other simulator
capable of dealing with nonlinear circuits).

Cheers,
Tom


David wrote:
Has anyone here used Superspice ?

I am looking for some information regarding setting up the Simulation
parameters to view Phase and Magnitude response for an oscillator
circuit (I have opened up the feedback path to enable a signal to be
injected through the amp and resonator.

I cannot find what I want in the documentation that came with the
software and the company has not replied to my email so I am hoping
someone else may be able to help.

Alternately if you know of a shareware or freeware simulator that could
I could use that has plenty of forum support ?

The exercise is to work through the book I have on computer simulation
"Oscillator Design and Computer Simulation" by Randall Rhea and see if I
can get the same results from the examples he gives (the version of his
book I have is the very first book sold and the software he used that
comes with the book is on an old disk I cannot read).

I have RFSIM99 but cannot see if I can get phase and magnitude
responses, I can get magnitude OK but want to have phase information
together with this to observe what the relationship is between them at
any given point.

Being "green" with regard to simulation, I do not want to purchase a
commercial simulator until I have some experience and am confident I
will be able to use it to obtain meaningful results.

Thanks in advance.

Tom

Oh, how unadventurous I were. You are correct, the phase selection is in
the pull down window.

Thanks for that. I will go back to RFSIM99.

Do you know if they ever made another version of this program or sell a
commercial version of it ?

Regards

David


K7ITM wrote:
I don't know exactly what you are trying to get the phase information
for, but RFSim99 can certainly display phase information for either or
both of its ports; it acts like a vector network analyzer. Just select
phase on the graphical display. It's in the pulldown menu on either
side of the graph window. Alternatively, you can save the results as
an S-parameter file.

With respect to using S-parameters in Spice, you should be able to
convert them to the domain that Spice understands with no trouble, at
least for discrete frequencies. It's more difficult if you need to
come up with a physical model that yields the desired S-parameter
performance over a range of frequencies. That's one of the really nice
things about RFSim99: you can instantiate a one-port or two-port that
uses an arbitrary set of S-parameters versus frequency. (Beware,
though, that the two-port model assumes a common terminal between the
two ports. And I've had trouble in the past trying to get an ideal
transformer give isolation; it seemed to want to assume the non-dotted
pins were both grounded. Try for example simulating port 1 feeding the
dotted pin of one side, the non-dotted grounded, and the dotted pin of
the other side grounded and the non-dotted pin feeding port 2. S11=0,
S21 = -208dB.)

It's good to keep in mind that S-parameters and RFSim99 deal only with
linear circuits. If your circuit is nonlinear, you should plan to use
the time-simulation capability of Spice (or use some other simulator
capable of dealing with nonlinear circuits).

Cheers,
Tom


David wrote:
Has anyone here used Superspice ?

I am looking for some information regarding setting up the Simulation
parameters to view Phase and Magnitude response for an oscillator
circuit (I have opened up the feedback path to enable a signal to be
injected through the amp and resonator.

I cannot find what I want in the documentation that came with the
software and the company has not replied to my email so I am hoping
someone else may be able to help.

Alternately if you know of a shareware or freeware simulator that could
I could use that has plenty of forum support ?

The exercise is to work through the book I have on computer simulation
"Oscillator Design and Computer Simulation" by Randall Rhea and see if I
can get the same results from the examples he gives (the version of his
book I have is the very first book sold and the software he used that
comes with the book is on an old disk I cannot read).

I have RFSIM99 but cannot see if I can get phase and magnitude
responses, I can get magnitude OK but want to have phase information
together with this to observe what the relationship is between them at
any given point.

Being "green" with regard to simulation, I do not want to purchase a
commercial simulator until I have some experience and am confident I
will be able to use it to obtain meaningful results.

Thanks in advance.

"David" wrote in message
...
Do you know if they ever made another version of this program or sell a
commercial version of it ?

The author, Stewart Hyde, didn't do so. See:
http://www.practicalrf.com/$Newsletter/e-letters/February2006/RFSim99.htm

Joel,

Thanks for the link to the interview. I wish the commercial versions of
software could be as simple to use as RFSIM99. I was ready to purchase
the Gold version of the Superspice simulator and requested some adice
from the manufacturer. Having sent 2 emails with no response I have
decided to continue using the freeware RFSIM99.

I find RFsim to be really easy to use. I am a novice with regard to
simulation but find the editor intuitive to us.

I have downloaded a number of "S-Parameter" files from manufacturers and
it is a breeze to use these. I suppose If I could afford a network
analyser I could develop a set of S-parameters for any device I use and
any bias condition.

Its a shame someone did not develop the program and offer a low cost
version with a few more features and support. I find the free version is
great and would have been happy to pay something for it.

Regards

David



Joel Kolstad wrote:
"David" wrote in message
...
Do you know if they ever made another version of this program or sell a
commercial version of it ?

The author, Stewart Hyde, didn't do so. See:
http://www.practicalrf.com/$Newsletter/e-letters/February2006/RFSim99.htm

Hi David,

"David" wrote in message
...
Thanks for the link to the interview. I wish the commercial versions of
software could be as simple to use as RFSIM99. I was ready to purchase the
Gold version of the Superspice simulator and requested some adice from the
manufacturer. Having sent 2 emails with no response I have decided to
continue using the freeware RFSIM99.

You might try posting to sci.electronics.design or sci.electronics.cad --
Kevin Aylward seems to read those on regular occasion.

Not to imply that ignoring your requests through his web site is acceptable,
of course.

I have downloaded a number of "S-Parameter" files from manufacturers and it
is a breeze to use these. I suppose If I could afford a network analyser I
could develop a set of S-parameters for any device I use and any bias
condition.

Yes, although de-embedding the fixture, mounting pads, etc. can sometimes be
annoying.

Depending on the frequencies you need to cover, there are several inexpensive
"homebrew" network analyzers out there... TAPR has one
(http://www.tapr.org/kits_vna.html), and there's another one kicking around
that's better for lower frequencies.

---Joel