taotaohai
Newbie level 3
Please help me expert analysis of this spectrum, the low-frequency noise sources.
First of all, my circuit is a multi-stage cascade, with a number of feedback loop of the limiting amplifier. Design goal is to achieve transfer rates of 20Gb / s data rate.
In the tape-test process, found before the frequency of 15GHz , there is a lot noise , a lot of clutter. The pseudo-random signal to 20Gb / s accession , the eye diagram poor.
The chart is the circuit output frequency spectrum only with power, not yet to join the ac signals .And the spectrum is an average of all frequencies on the map after.
I guess there may be two reasons: 1, multi-ring structure of the self-excited, resulting in a lot of points on the frequency noise spectrum; 2,problem in the layout, substrate noise is the main reason, there are a lot of noise
acoustic coupling, or incoming power supply noise coupling.
But this is only conjecture, please understand the spectrum of friends to help me analyze.
Thank you very much! ! Want to know more about the circuit, my email: taohaizhou@gmail.com
Please!
First of all, my circuit is a multi-stage cascade, with a number of feedback loop of the limiting amplifier. Design goal is to achieve transfer rates of 20Gb / s data rate.
In the tape-test process, found before the frequency of 15GHz , there is a lot noise , a lot of clutter. The pseudo-random signal to 20Gb / s accession , the eye diagram poor.
The chart is the circuit output frequency spectrum only with power, not yet to join the ac signals .And the spectrum is an average of all frequencies on the map after.
I guess there may be two reasons: 1, multi-ring structure of the self-excited, resulting in a lot of points on the frequency noise spectrum; 2,problem in the layout, substrate noise is the main reason, there are a lot of noise
acoustic coupling, or incoming power supply noise coupling.
But this is only conjecture, please understand the spectrum of friends to help me analyze.
Thank you very much! ! Want to know more about the circuit, my email: taohaizhou@gmail.com
Please!
