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timeresp

Time response for rational object and rationalfit function object

Description

example

[outputsignal,t] = timeresp(h,inputsignal,ts) computes the output signal that the rational function object produces in response to a give input signal at the specified sample time, ts.

Examples

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Define the input signal.

SampleTime = 2e-11;
OverSamplingFactor = 25;
TotalSampleNumber = 2^12;
InputSignal = sign(randn(1, ...
ceil(TotalSampleNumber/OverSamplingFactor)));
InputSignal = repmat(InputSignal, [OverSamplingFactor, 1]);
InputSignal = InputSignal(:);

Create a rational function object.

S = sparameters('default.s2p');
s21 = rfparam(S,2,1);
datafreq = S.Frequencies;
fit_data = rationalfit(datafreq,s21,'Tolerance',-32);

Compute the time response.

[y,t]=timeresp(fit_data,InputSignal,SampleTime);

Input Arguments

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Time varying input signal, specified as a real finite vector.

Data Types: double

Rational function object, specified as a rationalfit object.

Data Types: double
Complex Number Support: Yes

Sample time of the input signal, specified as a positive scalar integer in seconds.

Data Types: double

Output Arguments

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Time varying output signal, returned as a real finite vector.

Data Types: double

Sample time of the output signal, returned as a nonnegative vector of time values with discrete step size ts corresponding to the data in outputsignal in seconds.

Data Types: double

More About

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Output Signal Equation

timeresp function uses the variant of the following equation to calculate the output signal:

$Y\left(n\right)=sum\left(C.*X\left(n-Delay/ts\right)\right)+D*U\left(n-Delay/ts\right)$

where,

$\begin{array}{l}X\left(n+1\right)=F*X\left(n\right)+G*U\left(n\right)\\ X\left(1\right)=0\\ F=\mathrm{exp}\left(A*ts\right)\\ G=\left(F-1\right)./A\end{array}$

A— complex vector of poles of the rational function

C—complex vector of residues of the rational function

D—scalar value specifying direct feedthrough, and

Delay — delay time are properties of the rational function object, h. For more information, see rationalfit function.

Version History

Introduced in R2007a