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Rational Fitting and Time Domain Analysis

Fit frequency domain data to rational function, calculate time, step, impulse, and frequency response

Use the rational function to fit data defined in the frequency domain with an equivalent Laplace transfer function. Using rational function fitting you can create simple models for a required accuracy, model order reduction, zero phase on extrapolation to DC, and causal modeling system among other advantages.


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rationalPerform rational fitting on complex frequency-dependent data (Since R2020a)
rfmodel.rationalPerform rational fit using pole-residue representation of the component
timerespTime response for rational objects
steprespStep-signal response for rational object and rationalfit function object
freqrespFrequency response of rational object and rationalfit function object
pwlresp Calculate time response of piecewise linear input signal (Since R2021a)
impulseImpulse response for rational function object
ispassiveReturn true if rational fit output is passive at all frequencies
makepassiveEnforce passivity of rational fit
passivityPlot passivity of N-by-N rational fit output
iscausalDetermine if data is causal at specified frequency (Since R2023a)
abcdConstruct state-space matrices from rational object (Since R2020a)
zpkCompute zeros, poles, and gain of rational object (Since R2020a)
writevaGenerate Verilog-A description of rational object
generateSPICEGenerate SPICE file from rationalfit of S-parameters (Since R2019b)
ieee370QualityCheckFrequencyDomainCheck quality of measured S-parameter data using IEEE 370 standard (Since R2023b)