Features: Low SWR for reducing noise figure measurement uncertainty Individually calibrated ENR values at specific frequencies Calibration supplied on floppy disk for easy loading into NFA-series noise figure analyzers The Agilent 346A eliminates the necessity for several sources at different frequency bands. The low SWR of the Agilent noise source reduces a major source of measurement uncertainty; reflections of test signals. The very small change in reflection coefficient (<0.01) from ON to OFF is designed especially for accurate characterization of input-impedance-sensitive devices, like GaAsFETs and many UHF amplifiers.