# skrf.calibration.calibration.TwelveTerm¶

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

12-term, full two-port calibration.

TwelveTerm is the traditional, fully determined, two-port calibration originally developed in [1].

TwelveTerm can accept any number of reflect and transmissive standards, as well as arbitrary (non-flush) transmissive standards.

• If more than 3 reflect standards are provided, a least-squares
solution is implemented for the one-port stage of the calibration.
• If more than 1 transmissive standard is given the load match,
and transmission tracking terms are calculated multiple times and averaged.

References

 [1] “Calibration Process of Automatic Network Analyzer Systems” by Stig Rehnmark

Attributes

 biased_error Estimate of biased error for overdetermined calibration with multiple connections of each standard caled_ntwk_sets Returns a NetworkSet for each caled_ntwk, grouped by their names caled_ntwks List of the corrected calibration standards coefs Dictionary or error coefficients in form of numpy arrays coefs_12term Dictionary of error coefficients for 12-term Model coefs_12term_ntwks Dictionary or error coefficients in form of Network objects coefs_3term Dictionary of error coefficients for One-port Error model coefs_3term_ntwks Dictionary of error coefficients in form of Network objects coefs_8term Dictionary of error coefficients for 8-term (Error-box) Model coefs_8term_ntwks Dictionary of error coefficients in form of Network objects coefs_ntwks Dictionary of error coefficients in form of Network objects error_ntwk The calculated error Network or Network[s] family frequency Frequency object of the calibration normalized_directivity the directivity normalized to the reflection tracking nstandards number of ideal/measurement pairs in calibration output_from_run Returns any output from the run(). residual_ntwk_sets Returns a NetworkSet for each residual_ntwk, grouped by their names residual_ntwks Dictionary of residual Networks total_error Estimate of total error for overdetermined calibration with multiple connections of each standard.This is the combined effects of both biased and un-biased errors unbiased_error Estimate of unbiased error for overdetermined calibration with multiple connections of each standard verify_12term verify_12term_ntwk

Methods

 __init__ TwelveTerm initializer apply_cal apply_cal_to_all_in_dir apply_cal_to_list Apply correction to list of dict of Networks. embed Embed an ideal response in the estimated error network[s] from_coefs Creates a calibration from its error coefficients from_coefs_ntwks Creates a calibration from its error coefficients plot_caled_ntwks Plots corrected calibration standards plot_errors Plots biased, unbiased and total error in dB scaled plot_residuals Plot residual networks. pop Remove and return tuple of (ideal, measured) at index. remove_and_cal Remove a cal standard and correct it, returning correct and ideal run update_coefs update currect dict of error coefficients write Write the Calibration to disk using write()