43 AgendaAgilent Network Analysis Applying the 8510 TRL Calibration for Non-Coaxial MeasurementsProduct Note AAgilent De-embedding and Embedding S-Parameter Networks Using a Vector Network AnalyzerIn-Fixture Measurements Using Vector Network AnalyzersAgilent ANOtherAsymmetrical Reciprocal OptimizationTwo-Tier CalibrationSimplified 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.
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 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.
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.