Stats

  • Locked Locked
  • Replies 4
  • Subscribers 125
  • Views 14736
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Problem in accessing the X-values of a signal waveform

NorNand

Hello, 

I have this attached waveform that represents a frequency response of a model,

I am trying to find the frequency at where the output is maximum which represents for me the f2. the f1 I should find it as usual as for first-order circuits by multiplying the passband amplitude with 0.707 (which represent the - 3 dB), then f1 is the frequency at the resulted value.

I am trying to do it from Cadence calculator but looks like Xval function is not working,

for example Calculator is not giving me the Xval for the Ymax(Outputcap) to get f2, the same problem when trying to find f1

For your kind concern

Thank you

  • Not sure how OutputCap is being calculated, but it's possible that it's a complex number and so ymax doesn't work on it. Perhaps you need to do ymax(mag(OutputCap)) ? That would give the frequency where the magnitude of the OutputCap is maximum. Given the fact that the y axis shows Mag (fF) I suspect it is indeed a complex value (AC analysis results are normally complex, and then when plotted it wlll plot the magnitude by default, but functions like ymax, ymin etc do not automatically perform the mag() for you).

    Andrew.

  • in reply to Andrew Beckett

    Dear Andrew

    Thank you for your reply

    you are right, ymax was not working with me until I took the magnitude mag(OutputCap). However, Ymax will not give the frequency where the OutputCap is maximum, it gves me the value where OutputCap is maximum, means this function return the maximum y value while I am intereseting in the x value at the ymax, I already tested it.

    to find f1 I am doing the following but also not working:

    1. Applying Value function to OutputCap at f= 1 kHz

    2. Multiplying the value with 0.707

    3. applying Xvalue to the last steo in 2

    Thank you Andrew once again

    Regards

  • in reply to NorNand

    Sorry, I should have said you need to use xmax rather than ymax- this returns the x value where the maximum y is located. 

    Andrew

  • in reply to Andrew Beckett

    Thank you Andrew for your suggestion

    it is working now

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.