smlogan
Community Member
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Posts: 52
Boston, MA
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Hi Lunren,
After running the pss and pnoise simulation, use the ADE menu item Tools->Results browser. Navigate to the /schematic directory below the ADE. If you highlight schematic, you will then see the subdirectory /psf. Beneath psf, there is a directory listed "pnoise-pnoise". Highlighting this directory will show an output "out". If you import this into the calculator by clicking on "out", you may obtain and plot the phase noise (in dBc/Hz) by using the function "20dB" and clicking on "Plot" in the calculator. To add the phase noise output to ADE, use the menu Outputs->Setup... and in the resulting dialog box, click on the button "Get expression" alongside the "Calculator". This will import the function and output from the calculator. You may then name it something like "Phase noise" and hit the button "Add". This will add the phase noise output to your existing list of outputs.
In answer to your second question, there is no one "good" value of phase noise at a particular offset frequency to shoot for. The requirements of your circuit and its system requirements will dictate the required phase noise through its phase jitter , BER or other system parameter specifications. The analysis to derive the required phase noise at a specific offset frequency may not be unique. There may be many phase noise templates that achieve the required level of system or circuit performance.
Let me know if I've managed to understand your questions! Feel free to ask for clarifications!
Shawn
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