Designer’s Guide Community

jlee

Community Member

Offline

Posts: 40

How to get Y-parameter by netlist-run method?
Dec 29^th, 2007, 12:59am

Dear all,

I want to get Y11 by running netlist.

First, I use "spectre input.scs" in terminal to run SP, and then use "awd" to get data. But I can just get "S11". I tried to use calculator to get Y11, just like the GUI method that after runing SP, click Results -> Direct -> Main form -> YP..., but failed.

Is there anyone knows how to get Y11 by netlist-run ?

Thanks

Jason Lee

Back to top

IP Logged

ACWWong

Community Fellow

Offline

Posts: 539
Oxford, UK

Re: How to get Y-parameter by netlist-run method?
Reply #1 - Jan 2^nd, 2008, 6:50am

Hi Jason,

The y-parameters are postprocessed by ADE using the sp data. When simulating sp, only sp data is saved.
So you need ADE loaded with the results (by doing Results->select.... then point to the directory which is /path/testbenchname/spectre and the Name is the view you're using i.e. schematic). Then the calculator to get Y11 will work if launched from ADE.

If you don't want to use ADE, then you'll probably have to code the equations yourself from the getdata line. The spectreRF manual gives the equations used in Appendix E (of my version of spectreRF.pdf)

For example for a simple 1port y11 = (1/Rs)*(1-s11)/(1+s11)
where s11 is getData( "s11" ?result "sp-sp" ?resultsDir "/your_path") and Rs the port resistance.

cheers
aw

Back to top

IP Logged

jlee Community Member Offline Posts: 40	Re: How to get Y-parameter by netlist-run method? Reply #2 - Jan 2^nd, 2008, 7:12pm Thank you, aw Regards Jason
Back to top	IP Logged

Ken Kundert

Global Moderator

Offline

Posts: 2384
Silicon Valley

Re: How to get Y-parameter by netlist-run method?
Reply #3 - Jan 2^nd, 2008, 11:33pm

Y parameters are easy to compute with Spice. Just apply two voltage sources, one to each port, and run two AC simulations. In the first, set the AC magnitude of the input source to 1 and the output source to 0. Then Y11 is the current through the input source and Y21 is the current through the output source. With the second simulation, set the AC magnitude of the input source to 0 and the output source to 1. Then Y12 is the current through the input source and Y22 is the current through the output source.

-Ken

Back to top

IP Logged