1. Fixture Measurements
Doug Rytting

2. Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN
Other
Asymmetrical Reciprocal Optimization
Two-Tier Calibration and Simplified Error Models

3. Content of Application Note
TRL Calibration in Fixture
TRL Calibration on PC Board

4. Microstrip Test Fixture

5. Microstrip DUT in Fixture

6. Calibration Model

7. TRL Calibration Process

8. TRL Calibration Process Steps

9. Calibration Comparison

10. Calibration Comparison

11. PC Board TRL Calibration

12. PC Board vs Fixture

13. Time Domain of Launch and DUT

14. Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN
Other
Asymmetrical Reciprocal Optimization
Two-Tier Calibration and Simplified Error Models

15. Content of Application Note
De-embed Process
De-embed using ADS models

16. Text Fixture

17. Fixture Model

18. Definition of T-Parameters

19. S-Parameters and T-Parameters

20. Combine Fixture and NA Models Combing a Two-Tier Calibration

21. Definition of Error Terms

22. Definition of Error Terms

23. Fixture Model Using: Lossy Transmission Lines

24. Model of Coax to Microstrip Transition

25. Complete ADS Model of Test Fixture

26. Measured vs Modeled Fixture Optimize until Modeled Matches Measured

27. S11: De-embedded vs Coax Calibration Surface Mount Amplifier

28. S21: De-embedded vs Coax Calibration Surface Mount Amplifier

29. Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN
Other
Asymmetrical Reciprocal Optimization
Two-Tier Calibration and Simplified Error Models

30. Content of Application Note
Practical Considerations for Fixture Calibrations.
Time Domain Used to Reduce Errors.

31. Typical R&D Fixture

32. Direct Measurement Using Calibration

33. Two-Port Calibration

34. Determining Open Capacitance

35. Load Standard

36. Thru Standard

37. TDR Basics

38. TDR Basics

39. Gating The gating may include the launches by mistake.

40. Optimizing Load

41. Connectors on Fixtures

42. Connector Performance

43. Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN
Other
Asymmetrical Reciprocal Optimization
Two-Tier Calibration
Simplified Error Models

44. Asymmetrical Reciprocal Optimization
A passive asymmetrical reciprocal device is used in addition to short, open, load, and thru standards.
The errors in calibration kit parameters can be reduced through numerical optimization to minimize asymmetry after correction.
There are some potential convergence issues.

45. Asymmetrical Device

46. Before and After Optimization

47. Transmission Line Optimized Calibration
Measure S21m of a long transmission line.
Calculate S11c=S21mS21m of the transmission line.
Measure S11m of the transmission line with short connected to the end.
Subtract S11c from S11m for comparison.
Adjust capacitance of open to minimize ripple.
Adjust inductance of load and short to match the calculated S11c and measured S11m of the transmission line.
If possible, connect the load on the end of the long transmission line and adjust inductance of the load model for best performance. Then adjust the open and short models using a short connected to the end of the long transmission line.

48. Transmission Line Optimized Calibration Coax example using a 10 cm verification airline with a short on the end. Before and after optimizing the calibration standard’s models. Same approach can be used for fixture and on wafer measurements using a long verification transmission line.

49. Two-Tier Calibration
First tier calibration stored in network analyzer.
Second tier calibration performed with first tier calibration turned on.
First tier could be SOLT and second tier TRL. This method enables TRL calibration on a 3 receiver NA.
First tier could be at coax port of NA and second tier at ports of a fixture This process will characterize the fixture.

50. Simplified Error Model for Fixture Using Two-Tier Technique
Allows simpler second tier calibrations since number of error terms reduced from 7 to 6 due to reciprocity of the fixture.
For example, SOLT can be simplified to SOL since no thru is required.
Once fixture is characterized the data can be stored and used in future calibrations.
Many other simplified fixture calibrations are available.