A Comparison of Uncertainty Evaluation Methods for On-Wafer S-Parameter Measurements

An experimental analysis of on-wafer S-parameter uncertainties is presented. Recently, two different approaches, based either on differential numerical programming or on a fully analytical solution have been introduced. In order estabilish their suitability, a careful comparison is here given for on-wafer meaurements. Through this comparison, possible limitations and causes of errors are also highlighted. Finally, the uncertainty evaluation of the 16-term error model is here presented for the first time

Accuracy evaluation of on-wafer load-pull measurements

This paper investigates the residual calibration uncertainty effects in on-wafer load-pull measurements. After the systematic error correction (based on a traditional error-box model) has been applied, the residual uncertainty on absolute-power-level measurements can dramatically affect the accuracy of typical nonlinear parameters such as gain and power-added efficiency under different load conditions. The main residual uncertainty contributions are highlighted both by a theoretical analysis and experiments. Finally, one of the possible causes for intermodulation-distortion measurement errors is shown

Further Improvements in Real-Time Load-Pull Measurement Accuracy

This letter proposes a new solution to improve the accuracy of real-time load-pull measurement systems. Since it is well known that load-pull measurement accuracy depends on the calibration residual uncertainty, the presented solution uses a new algorithm to reduce it. Measurement results that corroborate the proposed solution, with respect to the previous one, show the improvements that have been achieved

Trends of Traceability and Accuracy Assessment in Vector Network Analyzer

Modern Vector Network Analyzers are powerful vector measurement systems for high frequency device characterization, in terms of scattering parameters. These instruments need a complex calibration procedure, aimed to remove the greater part of the errors associated to the hardware and to trace measurements to primary standards. Actually, these primary standards are only indirectly associated to SI fundamental electrical quantities. The more suitable standards are sections of transmission lines, characterized by means of dimensional measurements. The system accuracy is mainly related to the uncertainty of the standards , which propagates to the calibration coefficients of the network analyzer, according to the algorithms used by the calibration process. Systematic errors not removed by the calibration process, define a scattering matrix that must be anyway evaluated, for the final measurement uncertainty. Network Analyzer accuracy assessment after calibration process is widely described in the literature, but some clarifications are necessary, in order to avoid not consistent interpretations. For the same reasons, the measurand analysis would need a revision. Indeed, also in high-level comparisons, discrepancies arise among participants using instrumentation of equivalent performances, a result clearly due to different interpretation of the analysis rules. The authors suggest simple principles, in order to improve the harmonization of the measurement results

Unconventional Non-Intrusive Measurement and Modeling of Millimeter-Wave Devices

A fast, non-intrusive and low-cost methodology for characterizing and modeling planar devices with applications at millimeter-wave frequencies is investigated in this paper. The characterization process at such frequencies asks for the implementation of the real calibration standards models in the calibration algorithm. The influence of several parameters that appear in the characterization process has been analyzed for frequencies up to 36 GHz. An example of a Schottky diode characterization and modeling at microwave frequencies with further possible applications at millimeter-wave frequencies underlines the good accuracy level provided by the proposed methodology

Trends of traceability and accuracy assessment in Vector Network Analyzers

Modern Vector Network Analyzers are powerful vector measurement systems for high frequency device characterization, in terms of scattering parameters. These instruments need a complex calibration procedure, aimed to remove the greater part of the errors associated to the hardware and to trace measurements to primary standards. Actually, these primary standards are only indirectly associated to SI fundamental electrical quantities. The more suitable standards are sections of transmission lines, characterized by means of dimensional measurements. The system accuracy is mainly related to the uncertainty of the standards , which propagates to the calibration coefficients of the network analyzer, according to the algorithms used by the calibration process. Systematic errors not removed by the calibration process, define a scattering matrix that must be anyway evaluated, for the final measurement uncertainty. Network Analyzer accuracy assessment after calibration process is widely described in the literature, but some clarifications are necessary, in order to avoid not consistent interpretations. For the same reasons, the measurand analysis would need a revision. Indeed, also in high-level comparisons, discrepancies arise among participants using instrumentation of equivalent performances, a result clearly due to different interpretation of the analysis rules. The authors suggest simple principles, in order to improve the harmonization of the measurement results