Uncertainty in Large-Signal Measurements Under Variable Load Conditions

Area of Science:

• Electrical Engineering
• Solid-State Physics

Background:

• Accurate large-signal measurements are crucial for characterizing microwave transistors.
• Variations in load conditions introduce significant uncertainty in measurement results.

Purpose of the Study:

• To investigate the impact of varying load conditions on the uncertainty of large-signal microwave transistor measurements.
• To evaluate uncertainties in complex frequency-domain traveling voltage waves.
• To analyze how load reflection coefficient variations affect wave uncertainties and performance quantities.

Main Methods:

• Analysis of uncertainty sources typical for large-signal measurements.
• Evaluation of uncertainties in the magnitude and phase of traveling voltage waves.
• Mathematical modeling of the dependency of wave uncertainty on the load reflection coefficient.

Main Results:

• Uncertainty in traveling voltage waves is directly dependent on the load reflection coefficient.
• The total uncertainty of the waves, including magnitude and phase, was quantified.
• Identified unavoidable impact of these wave uncertainties on performance metrics like output power.

Conclusions:

• Load condition variations are a primary source of uncertainty in large-signal microwave transistor measurements.
• Understanding and quantifying wave uncertainty is essential for accurate transistor performance evaluation.
• The findings provide a basis for improving measurement accuracy and device modeling.