skrf.calibration.calibration.EightTerm¶

class
skrf.calibration.calibration.
EightTerm
(measured, ideals, switch_terms=None, isolation=None, ut_hook=None, *args, **kwargs)[source]¶ General EightTerm (aka Errorbox) Twoport calibration
This is basically an extension of the oneport algorithm to twoport measurements, A least squares estimator is used to determine the error coefficients. No selfcalibration takes place. The concept is presented in [1] , but implementation follows that of [2] .
See
__init__()
Notes
An important detail of implementing the errorbox model is that the internal switch must be correctly accounted for. This is done through the measurement of switch terms.
References
[1] Speciale, R.A.; , “A Generalization of the TSD NetworkAnalyzer Calibration Procedure, Covering nPort ScatteringParameter Measurements, Affected by Leakage Errors,” Microwave Theory and Techniques, IEEE Transactions on , vol.25, no.12, pp. 1100 1115, Dec 1977. URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=1129282&isnumber=25047 [2] Rytting, D. (1996) Network Analyzer Error Models and Calibration Methods. RF 8: Microwave Measurements for Wireless Applications (ARFTG/NIST Short Course Notes)
Attributes
T_matrices 
Intermediate matrices used for embedding and deembedding. 
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 12term Model 
coefs_12term_ntwks 
Dictionary or error coefficients in form of Network objects 
coefs_3term 
Dictionary of error coefficients for Oneport Error model 
coefs_3term_ntwks 
Dictionary of error coefficients in form of Network objects 
coefs_8term 
Dictionary of error coefficients for 8term (Errorbox) 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 
measured_unisolated 

measured_unterminated 

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 unbiased errors 
unbiased_error 
Estimate of unbiased error for overdetermined calibration with multiple connections of each standard 
verify_12term 

verify_12term_ntwk 
Methods
__init__ 
EightTerm Initializer 
apply_cal 
Apply correction to a Network 
apply_cal_to_all_in_dir 

apply_cal_to_list 
Apply correction to list of dict of Networks. 
embed 

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 
renormalize 
Renormalizes the calibration error boxes to a new reference impedance. 
run 
Runs the calibration algorithm. 
terminate 
Terminate a network with switch terms 
unterminate 
Unterminates switch terms from a raw measurement. 
update_coefs 
update currect dict of error coefficients 
write 
Write the Calibration to disk using write() 