# skrf.calibration.calibration.TwelveTerm.__init__¶

TwelveTerm.__init__(measured, ideals, n_thrus=None, trans_thres=- 40, *args, **kwargs)[source]

TwelveTerm initializer.

Use the n_thrus argument to explicitly define the number of transmissive standards. Otherwise, if n_thrus=None, then we will try and guess which are transmissive, by comparing the mean $$|s21|$$ and $$|s12|$$ responses (in dB) to trans_thres.

Notes

See func:Calibration.__init__ for details about automatic standards alignment (aka sloppy_input).

Parameters
• measured (list/dict of Network objects) – Raw measurements of the calibration standards. The order must align with the ideals parameter ( or use sloppy_input)

• ideals (list/dict of Network objects) – Predicted ideal response of the calibration standards. The order must align with ideals list ( or use sloppy_input

• n_thrus (int) – Number of transmissive standards. If None, we will try and guess for you by comparing measure transmission to trans_thres,

• trans_thres (float) – The minimum transmission magnitude (in dB) that is the threshold for categorizing a transmissive standard. Compared to the measured s21,s12 meaned over frequency Only use if n_thrus=None.

• isolation (Network object) –

Measurement with loads on both ports with a perfect isolation between the ports. Used for determining the isolation error terms. If no measurement is given leakage is assumed to be zero.

Loads don’t need to be same as the one used as a match standard or even have similar reflection coefficients. Reflects can be also used, but accuracy might not be as good.