Capabilities Below is a representative sample of our uncertainties.
Since the S parameters are dimensionless ratios, i.e. reflection and attenuation coefficients, a reference impedance must be specified. A 50 ohm impedance level is used for virtually all microwave devices calibrated. Thermistor mounts provide the basis for all microwave power measure-ments. Effective efficiency is transferred with a lower uncertainty than calibration factor because VNA techniques are used to eliminate all mismatch effects. Pulse power meter calibrations require Notch-wattmeter techniques.