RFSimm99 is a very good program. I also use a program called AppCad, from
the HP Woodshot website. When you talk about those excel spreadsheets, I am
not sure if you are referring to these programs, but for freeware, they are
very good.
There is also a program called RF Workbench.........this is a DOS program
that has an interface similar to AppCad, although RF Workbench will also do
spur charts for mixers.

Pete

"K7ITM" wrote in message
ups.com...
On Oct 15, 8:13 am, "Robert Lacoste" use-contact-at-www-alciom-com-
for-email wrote:
Hi,

Do you know if there is a raisonnable cost or even open source RF system
level simulator ? I mean a tool that allow someone to link boxes like
generators, mixers, filters, gain blocks, etc, all defined by their black
box parameters and simulate the system performances ? I know that high
end
tools like ADS have no poblem with that but I was wondering if there is
something smaller, say just a little more powerful than the classic
cascaded
gain IP3/p1dB/NF excel spreadsheets ?

Thanks,
Robert

The freeware RFSim99 will handle linear systems pretty well. You can
define two-ports with whatever set of S parameters you want and place
them schematically, and you can include passives and generic linear
amplifiers.

It's possible to use Spice (e.g. LTSpice). It would be possible to
define blocks including two-ports with specified nonlinearities and
mixers, and be able to input parameterized things like gain, IP3 and
NF. I've done some of that sort of thing for some system-level
simulations I've done.

But I suppose neither one of those ideas quite hits the target you've
put up...RFSim99 is turn-key but linear only, and Spice is potentially
powerful but not turn-key for your application.

Cheers,
Tom