From: Stefan Jahn <stefan@gr...>  20050706 06:28:26

On Mi, 6.07.2005, 05:24, John Steenbergen sagte: > Stefan, Hello John! > I tried to put this on the mailing list but I could not manage to get > subscribed to the help list for some reason. I was wondering if you could > help me with this. I am doing my best. > I would be willing to write up some > documentation/example > on this subject if you would like. This would be great. See qucs/qucshelp/docs/tutorial/ about how to do this. :) > I am trying to calculate constant gain circles using a 2port sparameter > file and the equation solver. The schematic is able to produce stability > circles just fine unsing the quation solver. Simulating the schematic > does give me an warning that S is not a defined varible and an error that > Gp is an undefined varible. The equation I am using is: > Gain GaCircle(S,Ga) > When only these equations are used it simulates just fine but with some > warnings: > StabSource StabCircleS(S) > StabLoad StabCircleL(S) I'll look at this tonight... But a first glance tells me: Ga is really undefined. In order to compute gain circle(s) with constant available gain Ga in the source plane you need to specify for which gain. Thus Ga=10 OR Ga=linspace(5,15,11) OR Gain=GaCircle(S,10) OR Gain=GaCircle(S,linspace(5,15,10)) may work better. > I am wondering if I need to define Gp and/or Gs or if they need to be > calculated? Not calculated but spcified. > I am attaching the schematic and s2p file just in case I > missed anything. Also I am using Qucs 0.0.6. I think you missed the s2p file to attach... Can you send it to me? > Thanks in advance. This program is really great. Thanks for all the hard > work. You're welcome. Thanks for trying Qucs, Stefan. 