S-Parameters Calculation - RF Cafe Forums
Post subject: S-Parameters Calculation Posted: Sun Aug
13, 2006 3:51 pm
Joined: Fri Aug 11, 2006
Is there a way to find the S-Parameters
of a system without doing all the calculations to get them? Assume
that I have a passive R network, is there a simulation program I
can put this circuit into and have it calculate the S-Parameters
Post subject: Posted: Tue
Aug 15, 2006 5:59 am
Joined: Mon Jun
27, 2005 2:02 pm
Basically any known RF simulation program will be able to calculate
the S-Paramaters of a passive R network (I assumre it is an attenuator).
You can try: Microwave Office and Genesys for example.
subject: RF SimulatorPosted: Tue Aug 15, 2006 11:28 am
Joined: Wed Feb 22, 2006 3:51 pm
Just a note on simulators:
Virtually every SPICE-based
simulator can be convinced to give you an impedance R+jX, which
can relatively easily be converted to S11 and S12.
are readily available - for example, NGSpice.
provides a remarkably good version of SPICE for free download, called
"SwitcherCAD" or "LTSpice". (Their angle: they provide models only
for Linear Technology's products. I can't criticize them for that,
because many device models are available online).
circuits, many providers will give you free "crippleware" - which
is good enough for small circuits. (PSpice from Mentor Graphics/OrCad
and TopSpice from Penzar Research, for example).
S21 can be gotten with not much more effort with the AC simulation
facility in SPICE. If you've got a pocket calculator, you can get
S parameters from Z or Magnitude/Angle.
A free/open source
RF simulator is "qucs", available online from SourceForge. It's
still relatively undeveloped, compared to Genesys or Microwave Office,
but if you're not yet to the point where those programs pay for
themselves, it's a way to get started.
Post subject: Posted: Tue Aug 15,
2006 4:54 pm
Joined: Wed Aug 20, 2003
Location: Santa Barbara, CA
a free RF simulator called RFSim99 that is pretty nice that outputs
S-Parameters directly. One link to get it is here:
Post subject: SimulatorPosted: Tue
Aug 15, 2006 8:39 pm
Joined: Wed Feb
22, 2006 3:51 pm
- I forgot about that one! It has the advantage of being a Windows
program, so easy to use and install. While it's not being updated
anymore as far as I know, it's a good piece of work.