Hi experts,
I am having problem with S-parameter simulation of 4 port for tranmission line. I have used "LTLINE2" component as my channel and I want to use this channel later for high-speed SERDES communication with differential TX/RX. But before that I need to know channel characteristics. May be after building a good channel here I can export the s-parameter file and use for other transceiver already built in Cadence. This is just for my basic simulation understanding. I have used controlled impedance line designer to put the line multilayer channel design inside the "LTLINE2" component. Now if I simulate the simulation result is not convincing, the S(2,1) or S(1,2) curves are linear not bumpy. What is wrong with my simulation setup or circuit or any other thing?
I have attached the screenshot of schematic and simulation in the attached file.
You help will be highly appreciated.
Hello,
This is Tim, author of Tim's blackboard.
For S21 to have ripples, the peak of S11 ripple needs to exceed -10 dB.
Because you optimized the coupled line to have 100 Ohm Zdiff, there is no mismatch and I expect S11 to be lower than -40 dB.
If you want to introduce ripples to S21, you need a pair of lines that's not well-matched.
Feel free to send me an email at tim.wang-lee@keysight.com
Tim