skrf.calibration.calibration.NISTMultilineTRL¶

class
skrf.calibration.calibration.
NISTMultilineTRL
(measured, Grefls, l, er_est=1, refl_offset=None, ref_plane=0, gamma_root_choice='estimate', k_method='multical', c0=None, z0_ref=50, z0_line=None, *args, **kwargs)[source]¶ NIST Multiline TRL calibration.
Multiline TRL can use multiple lines to extend bandwidth and accuracy of the calibration. Different line measurements are combined in a way that minimizes the error in calibration.
At every frequency point there should be at least one line pair that has phase difference that is not 0 degrees or a multiple of 180 degrees otherwise calibration equations are singular and accuracy is very poor.
By default the reference impedance of the calibration is the characteristic impedance of the transmission lines. If the characteristic impedance is known reference impedance can be renormalized by giving z0_ref and z0_line. Alternatively if capacitance/length of the transmission line is given with c0 argument, characteristic impedance can be solved assuming that conductance/length is zero.
Algorithm is the one published in [0], but implementation is based on [1].
References
[0]  DeGroot, J. A. Jargon and R. B. Marks, “Multiline TRL revealed,” 60th ARFTG Conference Digest, Fall 2002., Washington, DC, USA, 2002, pp. 131155.
[1]  Yau “On the metrology of nanoscale Silicon transistors above 100 GHz” Ph.D. dissertation, Dept. Elec. Eng. and Comp. Eng., University of Toronto, Toronto, Canada, 2011.
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 
er_eff 
Effective permittivity of the solved line. 
error_ntwk 
The calculated error Network or Network[s] 
family 

frequency 
Frequency object of the calibration 
gamma 
Propagation constant of the solved line. 
measured_unisolated 

measured_unterminated 

normalized_directivity 
the directivity normalized to the reflection tracking 
nstandards 
number of ideal/measurement pairs in calibration 
nstd 
Normalized standard deviation of the calibration error. 
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 

z0 
Solved characteristic impedance of the transmission lines. 
Methods
__init__ 
NISTMultilineTRL 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 
load_calibration_archive 

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. 
save_calibration 
save calibration as an archive containing the standards, parameters and calibration results 
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() 