Prabhu
Junior Member
![* *](https://designers-guide.org/forum/Templates/Forum/default/starblue.gif)
Offline
Posts: 23
|
Hi,
I am simulating the LNA + Mixer combination using PSS, PAC and PNOISE analysis ( I follow the method outlined in the cadence manual). LNA has a tuned LC load at the output. Mixer is a standard gilbert cell. I have individually characterized the LNA and mixer. When I do the PSS + PAC analysis of the combination and see the response at the LNA output, I see a lot of difference from the expected response.I see a gain of 50 (magnitude) in the place where I expect a gain of 10. Since PAC result is wrong, PNOISE result is also expected to be wrong. PSS does not give any convergence errors.
When I do a QPSS analysiswith LO as large tone and LNA input as medium tone , the results are consistent with the expected values. What could be wrong with the PAC analysis? Are there any special precautions to be taken while simulating the LNA + Mixer combination?
I am stuck with this problem and any help will be greatly appreciated.
Prabhu
|