Linear FM Metrics (Pulse)

Menu Path: Trace > Data > Result Tables

Menu Path: Trace > Data > Trend Lines

Menu Path: Trace > Data > Histograms

This topic describes the Linear FM Frequency Modulation metrics displayed in the Result Tables, Histograms, and Trend Lines.

• Best-Fit FM Mean (Hz)

  • Best-Fit FM Mean frequency in Hz, reports mean frequency of a best-fit linear least squares regression line measured over each pulse's user specified sample analysis time interval as determined by Frequency/Phase Analysis Width (%) property. [i.e. (Best-fit FM Start (Hz) + Best-fit FM Stop (Hz))/2].

  • Best-fit metrics are only valid when Linear FM is selected.

• Best-Fit FM Start (Hz)

  • Best-Fit FM Start frequency in Hz, reports start frequency of a best-fit linear least squares regression line measured over each pulse's user specified sample analysis time interval as determined by Frequency/Phase Analysis Width (%) property.

• Best-Fit FM Stop (Hz)

  • Best-Fit FM Start frequency in Hz, reports start frequency of a best-fit linear least squares regression line measured over each pulse's user specified sample analysis time interval as determined by Frequency/Phase Analysis Width (%) property.

• Best-Fit FM Pk-Pk Dev (Hz)

  • Best-Fit FM Peak-to-Peak Deviation in Hz, reports the absolute frequency deviation of a best-fit linear least squares regression line measured over each pulse's user specified sample analysis time interval as determined by Frequency/Phase Analysis Width (%) property. [i.e. absolute of Best-fit FM Stop (Hz) – Best-fit FM Start (Hz)]

  • Best-Fit FM Pk-Pk Dev (Hz) = abs(Best-Fit FM Stop (Hz) - Best-Fit FM Start (Hz))

• Best-Fit FM Slope (Hz/µs)

  • Best-Fit FM Slope in Hz/us, reports the frequency slope rate of a best-fit linear least squares regression line measured over each pulse's user specified sample analysis time interval as determined by Frequency/Phase Analysis Width (%) property.

• Best-Fit FM INL (%)

  • The Best-Fit FM Integral Non-Linearity in % metric is ratio of worst case peak frequency modulation error over peak-to-peak frequency deviation of a best-fit linear regression line applied to the measured FM sample data within user specified Pulse Frequency & Phase Analysis Range defined by parameter “Frequency/Phase Calculation Width” as a Percent of Pulse Top time interval (%).

  • Best-Fit FM INL (%) = (Freq Error Peak (Hz) / Best-Fit FM Pk-Pk Dev (Hz)) * 100.0%, , where Best-fit FM Error Peak (Hz) equates to reported FM Error Peak (Hz) metric value when FM Ref Time selection is Best-fit]