ispassive

Return true if rationalfit output is passive at all frequencies

Syntax

result = ispassive(fit)

[result,maxfreq,maxvalue] = ispassive(fit)

Description

result = ispassive(fit) determines if the rational fit input, fit is passive at all frequencies (0,Inf).

[result,maxfreq,maxvalue] = ispassive(fit) determines if the rational fit input, fit is passive at all frequencies (0,Inf).

Examples

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Check and Plot Passivity of N-by-N Rationalfit

Open Live Script

Read the file, passive.s2p and fit the 2-by-2 S-parameters.

S = sparameters('passive.s2p');
fit = rationalfit(S);

Test the passivity of the 2-by-2 fit.

ispassive(fit)

ans = logical
   0

Plot the passivity of the 2-by-2 fit.

figure
passivity(fit,[1e9 40e9])

Figure contains an axes object. The axes object with title Fit not passive, H indexOf infinity baseline blank n o r m blank i s blank 1 blank + blank 1 . 7 9 1 e - 0 2 blank a t blank 1 7 . 6 8 1 6 blank G H z ., xlabel Frequency (GHz), ylabel norm(H) contains 4 objects of type line. One or more of the lines displays its values using only markers

Input Arguments

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`fit` — Rational fit object
N-by-N array

Rational fit object, specified as an N-by-N array of rfmodel.rational objects as returned by the rationalfit function or a rational object.

Output Arguments

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`result` — Result of passivity test
`true` | `false`

Result of passivity test of the rfmodel.rational object, returned as true or false. The result tells you if the fit can result in unstable simulations.