Amplifier noise-parameter measurement checks and verification

We propose two verification methods for measurements of noise parameters of amplifiers, particularly low-noise amplifiers (LNAs). One method is a direct measurement of the parameter T rev, the noise temperature from the amplifier input, and the comparison of that to the value derived from the noise-parameter measurement. The other check involves the measurement of the noise parameters for the amplifier with an isolator connected to the input and comparison to the noise parameters of the amplifier alone. Relationships between the noise parameters with and without the isolator are given. We demonstrate both verification methods with measurements on a sample LNA in the 8 - 12 GHz range. Uncertainties in the noise parameters are evaluated using a previously developed Monte Carlo method, and both checks are found to be satisfied within the uncertainties.