System and method for calibrating a measuring arrangement and characterizing a measurement mount

• US 10,451,453 B2
• Filed: 02/20/2013
• Issued: 10/22/2019
• Est. Priority Date: 02/20/2012
• Status: Active Grant

• Current Assignee: Rohde & Schwarz GmbH & Company KG
• Original Assignee: Rohde & Schwarz GmbH & Company KG
• Inventors: Schmidt, Lorenz-Peter, Schramm, Marcus, Hrobak, Michael, Schur, Jan
• Primary Examiner(s): Kundu, Sujoy K
• Assistant Examiner(s): Anderson, L.
• Application Number:
  US14/379,741
• Publication Number:
  US 20150292921A1
• Time in Patent Office: 2,435 Days
• CPC Class Codes: G01D 21/00 Measuring or testing not otherwise provided for
• CPC Class Codes: G01R 27/28 Measuring attenuation, gain, phase shift or derived characteristics of electric four pole networks, i.e. two-port networks; Measuring transient response in line transmission systems H04B3/46
• CPC Class Codes: G01R 35/005 Calibrating; Standards or reference devices, e.g. voltage or resistance standards, "golden" references G01R33/0035, G01R35/002 take precedence

Abstract

A method and a system for calibrating a measuring arrangement on the basis of a 16-term error model determines a matrix (A) with measured scattering parameters (S_m) from different calibration standards (3) and with associated actual scattering parameters (S_a) of the calibration standards (3) and determines linear-in-T system errors (T_i) for the calibration of a network analyzer (1) by solving a linear equation system with the determined matrix (A). To solve the linear equation system, a first and a second linear-in-T system error (k, p) are freely selected in each case. With use of reciprocal calibration standards, the determined linear-in-T system errors are weighted with the freely selected first linear-in-T system error (T_i) or with a correct second linear-in-T system error p_kor(k)) dependent upon the first linear-in-T system error (k).

Claims

1. A method for characterizing a measurement holder connected to a network analyzer based on an error model, wherein the method comprises:

determining a matrix with measured scattering parameters from different calibration standards in the measurement holder and with associated actual scattering parameters of the calibration standards;

determining linear-in-T system errors of the error model by solving a linear equation system with the matrix; and

transforming the linear-in-T system errors into corresponding system errors of a system-error matrix of the error model which characterizes the measurement holder,

wherein in order to solve the linear equation system, a first and second linear-in-T system error are each selected and the given system error of the system-error matrix is weighted with a correct first linear-in-T system error or with a correct second linear-in-T system error,

a value of the correct first and correct second linear-in-T system error is determined by a reciprocity condition between two reciprocal transmission coefficients of a transmission path of the measurement holder in the system-error error matrix of a transmissive reciprocal calibration standard in the measurement holder, and

wherein system errors previously caused by the network analyzer and by measurement lines are determined by calibration, and the previously determined system errors are removed from the measured scattering parameters by the different calibration standards in the measurement holder.

2. The method according to claim 1, wherein the measurement holder is reciprocal with regard to its transmission.

3. The method according to claim 1, wherein the calibration standards include a total of four non-transmissive calibration standards;

and/or wherein the error model is a 16-term error model.

4. The method according to claim 1, wherein the value of the correct first and correct second linear-in-T system error is determined based on known electrical properties, including an electrical length, and two reciprocal transmission coefficients of a transmission path of the measurement holder in the system-error error matrix with the transmissive and reciprocal calibration standard in the measurement holder.

5. A method for characterizing a measurement holder connected to a network analyzer based on an error model, wherein the method comprises:

determining a matrix with measured scattering parameters from different calibration standards in the measurement holder and with associated actual scattering parameters of the calibration standards;

determining linear-in-T system errors of the error model by solving a linear equation system with the matrix; and

transforming the linear-in-T system errors into corresponding system errors of a system-error matrix of the error model which characterizes the measurement holder,

wherein in order to solve the linear equation system, a first and second linear-in-T system error are each selected and the given system error of the system-error matrix is weighted with a correct first linear-in-T system error or with a correct second linear-in-T system error,

wherein a value of a relationship between the first and second linear-in-T system error is determined by a reciprocity condition from transformed transmission factors of a transmissive and reciprocal calibration standard in the measurement holder, and

wherein the transformed transmission factors of the transmissive and reciprocal calibration standard in the measurement holder is implemented by transformation of measured transmission factors of the transmissive and reciprocal calibration standard in the measurement holder with the given linear-in-T system errors.

6. The method according to claim 5, wherein the value of the relationship between the first and second linear-in-T system error is determined based on known electrical properties, including an electrical length, and the transformed transmission factors of the transmissive and reciprocal calibration standard in the measurement holder.

7. A method for characterizing a measurement holder connected to a network analyzer based on an error model, wherein the method comprises:

determining a matrix with measured scattering parameters from different calibration standards in the measurement holder and with associated actual scattering parameters of the calibration standards;

determining linear-in-T system errors of the error model by solving a linear equation system with the matrix; and

transforming the linear-in-T system errors into corresponding system errors of a system-error matrix of the error model which characterizes the measurement holder,

wherein in order to solve the linear equation system, a first and second linear-in-T system error are each selected and the given system error of the system-error matrix is weighted with a correct first linear-in-T system error or with a correct second linear-in-T system error,

wherein a value of a relationship between the first and second linear-in-T system error is determined by a reciprocity condition from transformed transmission factors of a transmissive and reciprocal calibration standard in the measurement holder, and

wherein the value of either the correct first or the correct second linear-in-T system error is determined by a reciprocity condition between two reciprocal transmission coefficients of a transmission path of the measurement holder in the system error matrix with the transmissive and reciprocal calibration standard in the measurement holder.

8. The method according to claim 7, wherein the value of either the correct first or the correct second linear-in-T system error is determined by interrelations between known electrical properties, including an electrical length, and two reciprocal transmission coefficients of a transmission path of the measurement holder in the system error matrix of the transmissive and reciprocal calibration standard in the measurement holder.

9. The method according to claim 8, wherein the value of another correct first or correct second linear-in-T system error is determined on the basis of the determined value and of the determined sign to be additionally considered in the value of the first or the second linear-in-T system error and of the determined value and of the determined sign of the relationship between the first and second linear-in-T system error to be additionally considered.