Scattering parameter travelling-wave magnitude calibration system and method

1. A method for determining magnitudes of travelling-waves at a non-coaxial plane of a scattering (S) parameter measurement device, the S-parameter measurement device including an adapter link between the non-coaxial plane and a coaxial plane, the method comprising:

conducting a calibration at an interface between the adapter link and the coaxial plane to derive coaxial error terms for the S-parameter measurement device;

conducting a power meter measurement at the coaxial plane to obtain power wave measurements using the coaxial error terms;

conducting a calibration at an interface between the adapter link and the non-coaxial plane to derive non-coaxial error terms for the S-parameter measurement device; and

calculating a magnitude of a select one of the travelling-waves at the non-coaxial plane using the coaxial error terms, the power wave measurements and the non-coaxial error terms.

2. The method of claim 1 , wherein said conducting the calibration at the coaxial plane further comprises:

conducting a full two-port calibration at the coaxial plane to determine a first set of error terms; and

deriving the coaxial error terms for one coaxial port from the first set of error terms.

3. The method of claim 2 , wherein said conducting the calibration at the non-coaxial plane further comprises:

conducting a full two-port calibration at the non-coaxial plane to determine a second set of error terms; and

deriving the non-coaxial error terms for one non-coaxial port from the second set of error terms.

4. The method of claim 1 , wherein said conducting the power meter measurement further comprises:

attaching a power meter to a coaxial port of the S-parameter measurement device at the coaxial plane.

5. The method of claim 4 , wherein said conducting the power meter measurement further comprises:

determining a corrected reflection coefficient of the power meter using the coaxial error terms; and

determining a power meter reading.

6. The method of claim 1 , further comprising:

determining a magnitude of an additional one of the travelling waves at the non-coaxial plane.

7. The method of claim 1 , wherein said calculating further comprises:

extracting a calibration for the adapter link using an adapter removal algorithm to determine adapter error terms for the adapter link;

determining the S-parameters of the adapter link using the adapter error terms; and

calculating the magnitude of the select travelling-wave at the non-coaxial plane using the coaxial error terms, the power wave measurements, the non-coaxial error terms and the S-parameters of the adapter link.

8. The method of claim 7 , wherein said calculating further comprises:

determining a relationship between a measured value and a corrected value of the magnitude of an additional travelling-wave propagating across a zero-length thru at the coaxial plane towards the adapter link using the magnitude of a component of a composite one of the coaxial error terms.

9. The method of claim 8 , wherein the coaxial error terms include a reflection tracking error term equated to the product of two error coefficients, and wherein said determining the magnitude of the additional travelling-wave further comprises:

determining a value for the magnitude of one of the two error coefficients using the power wave measurements;

determining a value of a reflection coefficient one of the S-parameters of the adapter link; and

determining the magnitude of the additional travelling-wave using the value of one of the two error coefficients of the coaxial error terms and the value of the reflection coefficient S-parameter of the adapter link.

10. The method of claim 8 , wherein said calculating further comprises:

calculating the magnitude of the select travelling-wave using the magnitude of the additional travelling-wave, the S-parameters of the adapter link and a value of a reflection coefficient S-parameter at the non-coaxial plane calculated using the non-coaxial error terms.

11. In a scattering (S) parameter measurement system for use with an S-parameter measurement device including an adapter link between a non-coaxial plane and a coaxial plane, a memory medium comprising software programmed to determine magnitudes of travelling-waves at the non-coaxial plane by:

conducting a calibration at an interface between the adapter link and the coaxial plane to derive coaxial error terms for the S-parameter measurement device;

conducting a power meter measurement at the coaxial plane to obtain power wave measurements using the coaxial error terms;

conducting a calibration at an interface between the adapter link and the non-coaxial plane to derive non-coaxial error terms for the S-parameter measurement device; and

calculating a magnitude of a select one of the travelling-waves at the non-coaxial plane using the coaxial error terms, the power wave measurements and the non-coaxial error terms.

12. The memory medium of claim 11 , wherein said conducting the calibration at the coaxial plane further comprises:

conducting a full two-port calibration at the coaxial plane to determine a first set of error terms; and

deriving the coaxial error terms for one coaxial port from the first set of error terms.

13. The memory medium of claim 12 , wherein said conducting the calibration at the non-coaxial plane further comprises:

conducting a full two-port calibration at the non-coaxial plane to determine a second set of error terms; and

deriving the non-coaxial error terms for one non-coaxial port from the second set of error terms.

14. The memory medium of claim 11 , wherein said conducting the power meter measurement further comprises:

attaching a power meter to a coaxial port of the S-parameter measurement device at the coaxial plane.

15. The memory medium of claim 14 , wherein said conducting the power meter measurement further comprises:

determining a corrected reflection coefficient of the power meter using the coaxial error terms; and

determining a power meter reading.

16. The memory medium of claim 11 , wherein the method further comprises:

determining a magnitude of an additional one of the travelling waves at the non-coaxial plane.

17. The memory medium of claim 11 , wherein said calculating further comprises:

extracting a calibration for the adapter link using an adapter removal algorithm to determine adapter error terms for the adapter link;

determining the S-parameters of the adapter link using the adapter error terms; and

calculating the magnitude of the select travelling-wave at the non-coaxial plane using the coaxial error terms, the power wave measurements, the non-coaxial error terms and the S-parameters of the adapter link.

18. The memory medium of claim 17 , wherein said calculating further comprises:

determining a magnitude of an additional travelling-wave propagating across a zero-length thru at the coaxial plane towards the adapter link using the coaxial error terms and the S-parameters of the adapter link.

19. The memory medium of claim 18 , wherein the coaxial error terms include a reflection tracking error term equated to the product of two error coefficients, and wherein said determining the magnitude of the additional travelling-wave further comprises:

determining a value of one of the two error coefficients using the power wave measurements;

determining a value of a reflection coefficient one of the S-parameters of the adapter link; and

determining the magnitude of the additional travelling-wave using the value of one of the two error coefficients of the coaxial error terms and the value of the reflection coefficient S-parameter of the adapter link.

20. The memory medium of claim 18 , wherein said calculating further comprises:

calculating the magnitude of the select travelling-wave using the magnitude of the additional travelling-wave, the S-parameters of the adapter link and a value of a reflection coefficient S-parameter at the non-coaxial plane calculated using the non-coaxial error terms.

21. The memory medium of claim 11 , wherein the S-parameter measurement device includes a vector network analyzer.

22. The memory medium of 11 , wherein the memory medium is within the S-parameter measurement device.

23. The memory medium of claim 11 , wherein the S-parameter measurement device is controlled by an external computer system.

24. The memory medium of claim 23 , wherein the memory medium is within the computer system.

25. The memory medium of claim 23 , wherein the memory medium is a transportable computer-readable medium.

26. The memory medium of claim 11 , wherein the memory medium is flash ROM, EEPROM or EPROM.