Recommendations for simulator software.

[WPXS472]

I am looking for a source for rf circuit simulator software. I would like to find something that has optimization capability. I only need linear simulation. Don't need EM simulation. I have an anonymous copy of a hacked version of a very well known program whose name I will not mention. But, even after going through numerous tutorials, I still can't get it to do what I need. I used a previous version a few years ago with pretty good success, but they have made a lot of changes. Somewhere, I think I still have a copy of an old program for DOS that actually does a pretty good job. It uses nodal entry, and I remember getting proficient at entering circuits. The optimizer was pretty crude, but usable. I considered Qucs, because it has a good reputation, but doesn't optimize as far as I could tell. My circuit is only passive components, fairly low frequency.

[free_electron]

see if you can get an older version of APLAC from finnish university. it used to be freeware.

[2N3055]

Qucs does have some optimization...

http://web.mit.edu/qucs_v0.0.19/docs/en/start_opt.html

There is also QucsStudio.. A variant.. You can download it and there are optimization examples..

Maybe good enough for you..

[emece67]

.

[2N3055]

Linear simulation with only passive components at not so high frequency....Wouldn't plain Spice do the trick?

Keyword here is optimization...

[Berni]

Micro-cap is one of those spice simulators that has a lot of extra features like monte carlo tolerance analysis, optimization, etc..

It is a paid product that recently became abandonware so it is now free to use, but there will be no updates:
http://www.spectrum-soft.com/index.shtm

[WPXS472]

Thanks for the replies. Very useful.
I searched for APLAC, and found a reference to a student version, but no place to download. I will look into Qucs further. Sounds interesting. I downloaded Micro-Cap. I'll have to burn the CD and install it to see what it looks like. I used Spice a little a few years ago. I understand it can be very powerful, but I don't think it is the right tool for what I want to do. I understand that there are some newer free versions available, and I would like to try one sometime for another project. The reason I wanted to use optimization was due to the nature of the project. It will be a family of circuits, all with very similar circuits, but with different performance. In the past,I have done this kind of thing by getting one value to simulate correctly, then just enter new optimization goals for each value, and let the optimizer do the rest. The solutions often aren't exact, but close enough that I can finish using built prototypes and empirical methods.

[SiliconWizard]

Have a look at this project: http://asco.sourceforge.net/