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stepresp

Step-signal response for rational object and rationalfit function object

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Syntax

[outputsignal,tout] = stepresp(h,ts,n,trise)

Description

[outputsignal,tout] = stepresp(h,ts,n,trise) computes the time domain response of a rational function object, h, to a step signal based on the number of samples, n and the rise time, trise.

example

Examples

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Open Live Script

Calculate the step response of a rational function object from the file passive.s2p. Read passive.s2p.

S = sparameters('passive.s2p');
freq = S.Frequencies;

Get S11 and convert to a TDR transfer function.

s11 = rfparam(S,1,1);
Vin = 1;
tdrfreqdata = Vin*(s11+1)/2;

Fit to a rational function object.

tdrfit = rationalfit(freq,tdrfreqdata);

Define parameters for a step signal. Define parameters for a step signal

Ts = 1.0e-11;
N = 10000;
Trise = 1.0e-10;

Calculate the step response for TDR and plot it

[tdr,t1] = stepresp(tdrfit,Ts,N,Trise);
figure
plot(t1*1e9,tdr)
ylabel('TDR')
xlabel('Time (ns)')

Figure contains an axes object. The axes object with xlabel Time (ns), ylabel TDR contains an object of type line.

Input Arguments

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Rational function object, specified as a rationalfit or rational 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

Number of samples, specified as a positive scalar integer.

Data Types: double

Time taken for step signal to reach maximum value, specified as a positive scalar integer in seconds.

Data Types: double

Output Arguments

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Computed step response, 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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Step Signal Equation

RF Toolbox™ uses the following equation to for the step signal:

{U(kts)=kts/trise,U(kts)=1,  0≤k<(trise/ts)(trise/ts)≤k≤N

The following figure illustrates the construction of this signal.

Construction of step signal

Version History

Introduced in R2010a

See Also

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