Post on 27-Mar-2015
transcript
Slide 1
Fixture Measurements
Doug Rytting
Slide 2
Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note 8510-8A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
Product Note 8510-8A
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN 1287-9
OtherAsymmetrical Reciprocal OptimizationTwo-Tier Calibration and Simplified Error Models
Slide 3
Content of Application Note
TRL Calibration in Fixture
TRL Calibration on PC Board
Slide 4
Microstrip Test Fixture
Slide 5
Microstrip DUT in Fixture
Slide 6
Calibration Model
Slide 7
TRL Calibration Process
Slide 8
TRL Calibration Process Steps
Slide 9
Calibration Comparison
Slide 10
Calibration Comparison
Slide 11
PC Board TRL Calibration
Slide 12
PC Board vs Fixture
Slide 13
Time Domain of Launch and DUT
Slide 14
Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note 8510-8A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
Product Note 8510-8A
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN 1287-9
OtherAsymmetrical Reciprocal OptimizationTwo-Tier Calibration and Simplified Error Models
Slide 15
Content of Application Note
De-embed Process
De-embed using ADS models
Slide 16
Text Fixture
Slide 17
Fixture Model
Slide 18
Definition of T-Parameters
Slide 19
S-Parameters and T-Parameters
Slide 20
Combine Fixture and NA ModelsCombing a Two-Tier Calibration
Slide 21
Definition of Error Terms
Slide 22
Definition of Error Terms
Slide 23
Fixture Model Using:Lossy Transmission Lines
Slide 24
Model of Coax to Microstrip Transition
Slide 25
Complete ADS Model of Test Fixture
Slide 26
Measured vs Modeled FixtureOptimize until Modeled Matches Measured
Slide 27
S11: De-embedded vs Coax CalibrationSurface Mount Amplifier
Slide 28
S21: De-embedded vs Coax CalibrationSurface Mount Amplifier
Slide 29
Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note 8510-8A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
Product Note 8510-8A
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN 1287-9
OtherAsymmetrical Reciprocal OptimizationTwo-Tier Calibration and Simplified Error Models
Slide 30
Content of Application Note
Practical Considerations for Fixture Calibrations.
Time Domain Used to Reduce Errors.
Slide 31
Typical R&D Fixture
Slide 32
Direct Measurement Using Calibration
Slide 33
Two-Port Calibration
Slide 34
Determining Open Capacitance
Slide 35
Load Standard
Slide 36
Thru Standard
Slide 37
TDR Basics
Slide 38
TDR Basics
Slide 39
GatingThe gating may include the launches by mistake.
Slide 40
Optimizing Load
Slide 41
Connectors on Fixtures
Slide 42
Connector Performance
Slide 43
Agenda
Agilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial Measurements
Product Note 8510-8A
Agilent De-embedding and Embedding S-Parameter Networks Using a Vector Network Analyzer
Product Note 8510-8A
In-Fixture Measurements Using Vector Network Analyzers
Agilent AN 1287-9
OtherAsymmetrical Reciprocal OptimizationTwo-Tier CalibrationSimplified Error Models
Slide 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.
Slide 45
Asymmetrical Device
Slide 46
Before and After Optimization
Slide 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.
Slide 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 measurementsusing a long verification transmission line.
Slide 49
Two-Tier CalibrationFirst 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.
Slide 50
Simplified Error Model for FixtureUsing 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.