Noise parameters extraction for measurement system with large loss

Noise parameters extraction for measurement system with large loss is studied. Amplitude of selected source reflection coefficients are limited lower than 0.3. Three microwave devices with different optimum source reflection coefficient amplitudes (0.2, 0.5, 0.8) are specified. Each device is assumed according to measurement experience. In the simulation experiment, for each device, noise parameters are extracted based on least-squares method and genetic algorithm. The results show that source reflection coefficients with amplitudes lower than 0.3 cannot guarantee the accuracy of noise parameters for all specified devices. Even though standard deviation of noise parameters extracted by genetic algorithm are smaller than those extracted by least-squares method sometimes, the mean values plus standard deviations may also deviate from specified values.