Thevenin and S parameters - RF Cafe Forums
Because of the high maintenance needed to monitor and filter spammers from the RF Cafe Forums, I decided that it would be best to just archive the pages to make all the good information posted in the past available for review. It is unfortunate that the scumbags of the world ruin an otherwise useful venue for people wanting to exchanged useful ideas and views. It seems that the more formal social media like Facebook pretty much dominate this kind of venue anymore anyway, so if you would like to post something on RF Cafe's Facebook page, please do.
Below are all of the forum threads, including all the responses to the original posts.
Post subject: Thevenin and S parameters... Posted: Fri Jan 26, 2007 11:18 am
Joined: Fri Jan 19, 2007 10:36 am
I’m have “little” doubt about s-parameter simulations . My question is very simple but I do not know if the answer is the same .
The Thevenin theorem can be applied to a s-parameter simulation?
That is, if I do a simulation using a port P1 with 50 ohm where at valley of the port I’ve connected 2 impedences, one in parallel Z1 and one in series Z2. Supposing I obtained S11 at frequency f1. Then, if I incorporate the impedence Z2 (at frequency f1) in the port 1 impedence (using Thevenin), can I obtain the same S11 parameters for f1 fequency?
Post subject: Posted: Fri Jan 26, 2007 3:18 pm
Joined: Mon Jun 27, 2005 2:02 pm
In S-parameters you can short voltage sources, but you can't create an open circuit which is required to create the equivalent resistance for Thevenin. You can only connect the network characteristic impedance to derive each of the S-parmaters.
Hence Thevenin theorem applies only at DC and low frequency networks where it is possible to use open-circuit, but not to RF/Microwave networks.
More than 10,000 searchable pages indexed.