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
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page, please do.
Below are all of the forum threads, including all
the responses to the original posts.
Post subject: Transmission line design Posted: Sat Jul 22, 2006 3:10 pm
Joined: Tue Feb 21, 2006 5:19 pm
What's the best way of designing transmission line
matching circuits using CAD tools? I am doing a simple single stub tuned match. I have a series line and a
open-circuit shunt stub. I used the ideal Tline components in ADS to design the match so I have the value of
electrical lengths for both series and the stub. Then, since I know the frequency and effective permittivity I got
the approx. guided wavelength; then using
physical length (L) = ((guided wavelenth)*(electrical
I got the approx. physical length of the transmission line. Then, I went in Sonnet and drew
up the line and did EM simulation. But, now I am stuck. For series line, I pretty much was able to match what ADS
had i.e. if the electrical length was 20 deg in ADS for series line, its S21 mag. and phase was close to the line
simulated in Sonnet. However, I cannot get the Sonnet simulation to match the open-circuit stub. Its phase way way
different and I can't figure it out.
Is the way I am doing sound? Now, I am doubting about using the ideal
Tlines but my thinking was as long as I am able to match s-param, especially S21, of these ideal Tlines to the
simulated lines it should give me the same match.